YamEen Uncategorized

6 Environmental science Social Issues part 2

Rehabilitation should be collective
In the villages, almost each’ family depends on the other. The social and moral obligations
towards each other bind them into one cohesive whole. The authorities are rehabilitating
individual families and not the village as a whole.
Monetary Compensation
Mere payment of cash is not rehabilitation. Moreover, the amount of cash paid as
compensation is insufficient to buy land in other places because of the high rates. The
oustees being basically farmers lack the business acumen needed to set up a viable commercial
alternative. Since they are not accustomed to having such large sums (relative to their
usually small incomes) in a lump sum, they are ignorant as to how they should spend it.
Mismanagement
The project authorities estimated the total affected population in 1981 as 46,000. Using
the Census Office figures, the total number affected for 1981 is act 70,000.
Lack of Public Relations
The majority of populace to be displaced consists of advises, tribal, scheduled castes
that have a unique lifestyle. The traumatic experience of shifting to new areas and new
occupations involving drastic changes in their lifestyle weighs heavily on these people. The
absence of any public relation efforts has further aggravated the situation.
Housing compensation: It is necessary to highlight a major flaw in the procedure for
fixed immovable property like houses, well, barns fence, cattle-stalls, etc. The present
procedure evaluates the “current worth” or “value after depreciation” for determining the
amount of compensation. This concept is faulty. He should be paid an amount for his house
etc., equivalent to the cost of reconstructing a dwelling place equal to the plinth area lost
under submergence. This amount (i.e., replacement cost) will obviously be more than the
“current worth” of his old dwelling.
Environmental Ethics
The Earth is unique among all the planets in our solar system. It is endowed with
plentiful resources. Man’s greed to raise his standard of living compels him control and tap
natural resources. Many. rivers throughout the world have been “controlled” to provide
power, irrigation, and navigation for the people at the expense of the natural world. If such
gifts of nature are not tapped for resource generation, many people think it to be wastage
of resources. The capitalists want to use the forests for timber production and not doing so
is closely linked to economical hardships. Removing the trees would destroy something that
took hundreds of years to develop and may never be replaced. Efforts to manage the
interactions between people and their environment are an age-old practice. At one time,
pollution was a local, temporary event, but today, pollution problems have crossed
international borders and have become global. The seminars over chemical and radioactive
waste disposal witness the increasingly international nature of pollution.
Ethical issues dealing with the environment are no different from other kinds of problems.
The concept of an environmental ethics could encompass differing principles and beliefs.
Ethics is one branch of philosophy, which fundamentally attempts to define what is right,
and what is wrong, regardless of cultural differences. Environmental ethics are formulated
on the basis that human beings are also a part of nature and nature has many interdependent
components. In any natural ecosystem, the well being of the individual and of each species
is linked to the well being of the entire community. In a world increasingly without
environmental borders, nations, like individuals, should have a fundamental ethical
responsibility to respect nature and to care for the Earth, protecting its life-support systems,
biodiversity, and beauty, caring for the needs of other countries and future generations.
Environmental ethicists argue that to consider environmental protection as a “right” of the
planet is a natural extension of concepts of human rights.
Although there are many different attitudes about the environment. Three types of the
ethics are identified as (a) the development ethic, (b) the preservation ethic, and (c) the
conservation ethic. Each of these ethical positions has its own appropriate code of conduct
against which ecological mortality may be measured.
The development ethic is based 011 actions. Development in any sector is inevitable.
. But the development should not crop up at the cost of environmental failure. This philosophy
is strengthened by the idea that, “if it can be done, it should be done.”
The preservation ethic considers nature special in itself. Some preservationists have
an almost religious outlook regarding nature. They believe that nature is beautiful place to
live in and it should be maintained for feeding, breeding, enjoyment and peace. On the other
hand scientific outlook argue that the human species depends on and has much to learn
from nature. Rare and endangered species and ecosystems, as well as the more common
ones, must be preserved because of their known or assumed long-range, practical utility.
The third environmental ethic is referred to as the conservation ethic, It recognizes
the desirability of decent living standards, but it works towards a balance of resource use
and resource availability.
Economic growth and resource exploitation are attitudes shared by developing
societies. As a society, we continue to consume natural resources as if the supplies were
never ending. All of this is reflected in our increasingly unstable relationship with the
environment, which grows out of our tendency to take from the “common good” without
regard for the future.
Global Environmental Ethics
This new sense of urgency and common cause about the environment is leading to
unprecedented cooperation in some areas. Ecological degradation in any nation almost
inevitably impinges on the quality of life in others. For years, acid rain has been a major
irritant in relations between the United States and Canada.
Conclusion
Will the nations of the world be able to put aside their political differences to work
towards a global environmental course of action? Out of that international conference was
born the U.N. Environment Programme a separate department of the United Nations that
deals with environmental issues. Through organizations such as this nations can work
together to solve common environmental problems. Deep ecologists, on the other hand, see
humankind itself as the main problem. They believe that the earth is a complex organism
with its own needs, metabolism; and immune system and that humankind’s relationship
with the earth is increasingly parasitic. In the book Deep Ecology: Living Nature. As If
Nature Mattered, proponents Bill Devall and George Sessions, clearly state their principles:
(1) Humans have no right to reduce the richness and diversity of life except to satisfy vital
needs: (2) the quality of human life and culture is compatible with a substantial decrease
in the human population; and (3) the flourishing of non-human life requires such a decrease.
To secure for current and future generations a safe and healthy environment, a sound
and prosperous economy should aim at:
1. Ensure that citizens today and tomorrow have the clean air water, and land essential
to sustaining human health and the environment.
2. Protect and enhance, the quality of water resources and promote the wise and
efficient use of water.
3. Maintain and enhance the health and diversity of the wildlife and planets.
4. Develop an environmentally literate society.
Climate Change
Introduction
The recent interest in global warming and sustainable development has become a
global talk. The most important global environmental topics as chosen by a panel of about
12 world experts were as follows: human population growth, bio-diversity and conservation,
climate change, forest decline, hazardous wastes, land degradation, human pathogens, urban
environment, work environment and resource depletion. Man is as closely related to nature
as he is to himself, because he is a part of it. An outright dependence on nature has been
a striking feature of man’s progress through the centuries of his struggle.
Climate has from the very beginning regulated man in practically every aspect of life
and has played a very important role in the development of civilizations all around the
world. Man’s impact on climate began 5000 to 9000 years ago, as he was able to alter the
environment by burning and felling forest and tilling the earth. The most extensive change
wrought by man prior to our own times was the gradual conversion of most of the temperate
forest zone to crops that is an artificial steppe or savanna. Thus until the industrial revolution
and probably until the present century, man had little effect on the climate except on a very
local scale.
Presently global warming has emerged as one of the most important environmental
issues ever to confront humanity. This concern arises from the fact that our everyday
activities may be leading to changes in the earth’s atmosphere that have the potential: to
significantly alter the planet’s heat and radiation balance, and thereby lead to a warmer
climate in the next century and thereafter. International efforts to address this problem
have been on for the last decade, with the Earth Summit at Rio in 1992 as an important
launching point and the Conference of Parties in Buenos Aires. In 1998 as the most recent
step. Although India as a developing country does not have any commitments or
responsibilities at present for reducing the emissions of greenhouse gases such as carbon
dioxide (CO2) that lead to global warming, pressure is increasing on India and other large,
rapidly developing countries such as China and Brazil to adopt a more pro-active role.
What is Climate Change?
Climate change is a newcomer to the international political and environmental agenda,
having emerged as a major policy issue only in the late 1980s and thereafter. It has emerged
since the 19th century that CO2 in the atmosphere is a ‘greenhouse gas’, that is, its presence
in the atmosphere helps to retain the incoming heat energy from the sun, thereby increasing
the earth’s surface temperature. Of course, CO2 is only one of several such greenhouse gases
in the atmosphere. Others include methane, nitrous oxide and water vapour. However, CO2
is the most important greenhouse gas that is being affected by human activities. CO2 is
generated by a multitude of processes. Since the Industrial Revolution, when our usage of
fossil fuels increased dramatically, the contribution of CO2 from human activities has grown
large enough to constitute a significant perturbation of the natural carbon cycle.
The concentration of CO
2 in the Earth’s atmosphere was about 280 parts per million by
volume (ppmv) in 1750, before the Industrial Revolution began. By 1994 it was 358 ppmv
and rising by about 1.5 ppnw per year. If emissions continue at the 1994 rate, the
concentration will be around 500 ppmv, nearly double the pre-industrial level, by the end
of the 21st century.
Rising Concentrations
The effect is that the atmosphere retains more of the Sun’s heat, warming the Earth’s
surface. While the pattern of future warming is very much open to debate, it is indisputable
that the surface of the Earth has warmed, on average, 0.3 to 0.6 °C since the late 19th
century when reliable temperature measurements began. Under the existing scenarios of
economic growth and development leading to greenhouse gas emissions, on a worldwide
average, temperatures would rise by 1 to 3.5 °C by the year 2100, and global mean sea level
by about 15 to 95 cm. It is likely that changes of this magnitude and rapidity could pose
severe problems for many natural and managed ecosystems. Indeed, for many low-lying and
deltaic areas and small islands, a sea level rise of one meter could threaten complete Joss
of land and extinction of habitation.
Extreme Weather Events
In addition, most of the ill effects of climate change are linked to extreme weather
events, such as hot or cold spells of temperature, or wet or dry spells of rainfall, or cyclones
and floods. Predictions of the nature and distributions of such events in a changed climate
are even more uncertain- to the extent that virtually no authoritative predictions exist at
all. While there are costs as well as benefits associated with climate change, the scientific
consensus is clearly that the overall effects are likely to pose a significant burden on the
global community. Unlike many other environmental issues, such as local air or water
pollution, or even stratospheric ozone depletion caused by chlorofluorocarbons (CFCs), global
warming poses special challenges due to the spatial and temporal extent of the problem
covering the globe and with decades to centuries time scales.
Analysis and assessment of just what steps needed to be taken to limit greenhouse gas
emissions. This process resulted in the negotiation’ of a protocol, the final details of which
were completed at the third meeting of the Conference of the Parties to the Framework
Convention held December 1-12, 1997, in Kyoto, Japan. The Kyoto Protocol to the United
Nations Framework Convention on Climate Change commits industrialized nations to specific,
legally binding emission reduction targets for six greenhouse gases: carbon dioxide, methane,
nitrous oxide, hydro fluorocarbons, per-fluorinated compounds and sulphur hex fluoride.
First, although India does not currently have any obligations under the Convention to
reduce its greenhouse gas emissions. It is important for us to develop a clear understanding
of our emission inventory. We also need to document and analyze our efforts in areas such
as renewable energy, wasteland development and a forestation – all of which contribute
towards either reducing CO2 emissions or increasing CO2 removal from the atmosphere.
Considering that these efforts may often be undertaken for a variety of reasons not directly
related to global warming, but yet has benefits as far as climate change is concerned, we
may be able to leverage such efforts in the international context. The Research community
could contribute substantially in this regard. We need to significantly improve our ability
to plan and adapt to extreme events such as floods, droughts, cyclones and other meteorological
hazards. Any robustness that we build into the system in this regard will always stand us
in good stead no matter what climate change actually transpires.


Global Warming and the Greenhouse Effect

In the late 1900’s researchers realized that the world may be getting warmer. The last
two decades of the 1900’s witnessed some warm and cool years. However, not enough
evidences were available to support the theory of global warming. But this a well-known fact
that accumulation of several green house gases can lead to a rise in temperature (global
warming). If a global warming phenomenon sets in this would result in major changes in
world’s climate. The increase in temperature might lead melting of snow on poles, which
would terrifically add, to ocean waters. Hence the level of seas, and oceans would rise, this
would largely affect the coastal areas. These would submerge under coastal Waters due to
expansion of seas and oceans. Besides the Temperate climate pattern would shift northward
and present temperate regions would become hot & dry.
The Greenhouse Effect is a natural phenomenon that plays a central role, in determining
the earth’s climate. The hot surface of the sun radiates heat and light energy. Several gases
in the atmosphere are transparent to light but absorb infrared radiation. These allow sunlight
to pass through the atmosphere and be absorbed by the earth’s surface. This energy ,is
again radiated as heat energy, which is absorbed by the gases. As the effect is similar in
nature to what happens in a’ botanical greenhouse (the glass panes allows the light energy
to enter inside but diminishes the loss of heat), these gases are called greenhouse gases and
the resultant warming from their increase is called the greenhouse effect. Anthropogenic
activities add to the phenomenon accelerating greenhouse gas building process. Global increase
of greenhouse gases in the atmosphere viz., carbon dioxide, nitrous oxide, methane and
chlorofluorocarbons are now well documented. In addition to all these changes, troposphere
and stratospheric chemistry are being modified due to the addition of these gases as well
as emission of carbon monoxide, nitrogen oxides and other compound. The United State
Environmental Protection Agency, Office of Policy, Planning and Evaluation in 1989 have
documented the increase of the different green house gases.
Table 6.1: Major Green House Gases Contributing to Global Warming
Sl.No. Gas Contribution to global
warming
1. Carbon dioxide 57
2. Chlorofluorocarbons 25
3. Methane 12
4. Nitrous oxide 6
The concentration of carbon dioxide into the atmosphere has increased by 25% since the
industrial revolution. Carbon dioxide is increasing at a rate of about 0.4% per year and is
responsible for about half of the current increases in the greenhouse effect. The concentration
of methane has more than doubled during the last three centuries. Agricultural sources
particularly rice cultivation and animal husbandry has probably been the most significant
contributors to historical increase in concentrations. But there is the potential for rapid
growth in emissions from landfills, coal seems, permafrost, natural gas explorations and
pipeline leakage, and biomass burning associated with forest clearings in the future.
The concentrations of nitrous oxide have increased by 5-10% since pre-industrial times.
The cause of this increase is highly uncertain, but it has been understood that the use of
nitrogenous fertilizer, land clearing biomass burning and fossil fuel combustion have all
contributed. Nitrous oxide is currently increasing at a rate of about 0.25% per year, which
represents and imbalance between sources and sinks of about 30%. CFC’s were introduced
into the atmosphere for the first time during the century; the most common species are
CFC-12 and CFC-II. Of major concern because of their potential to deplete stratospheric
ozone, the CFCs also represent about 15% of the current increases in the greenhouse effect.
The chemistry of the atmosphere is changing due to emission of carbon monoxide,
nitrogen oxides, and volatile organic compounds, among other species, in addition to the
changes in the greenhouse gases already described. This alters the amount and distribution
of ozone and the oxidizing power of the atmosphere. which changes the lifetimes of methane
and other greenhouse gases. Changes in global ozone are quite uncertain, and may have
contributed to an increase or decrease in the warming commitment during the last decade.
Acid Rain
Although the phenomenon of “acid rain” (more correctly acid deposition) was identified
in Manchester, England, as long ago as 1852, and described more thoroughly in 1872,
modern scientific research has been going on only since the mid-1950s. Public concern about
the problem began in the late 1960s. Acid rain is an environmental hazard that is transponder
in nature. Northeastern America, North Western Europe and India are facing an acute
problem of acid rain. Acid rain has affected certain rivers, lakes, streams and forests in
United Kingdom (UK), United States of America (USA), Germany and many other countries.
Acid rain literally means ‘the presence of excessive acids in rain waters’. Acid precipitation
is a mixture of strong mineral acids sulphuric acid (H2SO4), nitric acid (HNO3) and in some
locations, hydrochloric acid (HCl). It usually has a ph of less than 5.6, the value of distilled
water in equilibrium with atmospheric carbon dioxide.
Acid in the Rain Water’s
Acid rain problem is a result of anthropogenic activities. Most acids come from cars,
homes, industries and power stations but some share is contributed by natural sources such
as volcanoes, swamps and planktons. The acid problem is basically associated with the
transport and subsequent deposition of oxides of sulphur, nitrogen and their oxidative
products. These are produced by combustion of fossil fuels, power plants, automobile exhausts
and domestic fires etc.
Formation of Acid Rain
Acid rain is one of the form of acid deposition which can either be wet or dry, acid rain,
snow, dew, fog, frost and mist are the wet form of deposition, while dust particles containing
sulphate and nitrates which settle on ground is called dry deposition.
Wet Acid Rain
Coal, fuel wood or petroleum products have sulphur and nitrogen. These elements,
when burnt in atmospheric oxygen,’ are converted into their respective oxides (SO2 and
NO
3), which are highly soluble in water. By anthropogenic and by natural sources, oxides
of sulphur and nitrogen enter the atmosphere.
Reactions
Reaction with Sulphur
S + O
2 = SO2
2SO
2 + O2 = 2SO3
Reaction with Nitrogen
NO + O
3 = NO2 + O2
NO
3 + NO2 = N2O5
When air is saturated with water droplets (humid conditions), N2O5 invariably reacts
with water vapors to form droplets of HNO3.

N2O5 + H2O = 2HNO3Besides some HNO2 is also formedN2O3 + H2O = 2HNO2SO3 in humid conditions forms droplets of H2SO4.SO2 + 1/202O2 + H2O = H2SO4HNO3 and H2SO4 thus formed combine with HCl to generate precipitation, which iscommonly referred to as acid rain.The primary reason for concern is that acid deposition acidifies streams, and taken oncoarse, sandy soils low in lime: The effect is seen particularly in headwater areas and in wetmontane environments, wherever sulphate loading from anthropogenic sources is strong.The chemical and physical consequences of lake acidification include, increased leaching ofcalcium from terrestrial soils, mobilization of heavy metals such as aluminium, zinc, andmanganese and an increase in the transparency of lake waters. The biological consequencesinclude market changes in communities of aquatic plants and animals, with a progressivelessening of their diversity.Acid deposition may further impoverish forests soils, developed on sandy substrata poorin lime. As a consequence of accelerated leaching of nutrients, such as phosphorous, potassium,magnesium and calcium from these soils, forest productivity would eventually be reduced.Moreover, the acid sulphate particles that contribute to acid precipitation are in the sizerange that penetrates deep into the lung, and they may well exacerbate lung diseases andincrease mortality rates.Ozone Layer DepletionJoseph Farman, of the British Meteorological Survey, and colleagues reported in thescientific journal Nature that concentrations of stratospheric ozone above Antarctica hadplunged more than 40 percent from 1960s baseline levels during October, the first monthof spring in the Southern Hemisphere, between 1977 and 1984. It meant that for severalmonths of the year a hole forms in the ozone layer, which protects animals and plants fromultraviolet solar radiation. Suddenly it seemed that the chemical processes known to depleteozone high in the earth’s atmosphere were working faster and more efficiently than predicted.Chemistry of the Ozone LayerOxygen molecules (O2), abundant throughout the atmosphere, are split apart intoindividual atoms (O + O) when energized by radiation from the sun. These atoms are freeto collide with other O2 molecules to form ozone (O3). The particular configuration of theozone molecules allows them to absorb the sun’s radiation in ultraviolet wavelengths thatare harmful to life if they penetrate to the earth’s surface. The ozone molecules formed bycollision are partially removed by other naturally occurring chemical reactions, and so theoverall concentration of stratospheric ozone remains constant. High above the stratosphere,the density of gases is. so low that oxygen atoms rarely find other molecules to collide with,and ozone does not form in abundance. Below the ozone layer, too little solar radiationpenetrates to allow appreciable amounts of ozone to form. Thus most of the world’s ozone
is in a stratospheric layer bulging with ozone at latitudes from 10 to 35 kilometers.
Closer to the ground, in the troposphere, ozone produced through a series of chemical
reactions involving hydrocarbons and nitrogen oxide emissions from vehicles and industrial
activity is an effective greenhouse gas. Thus, ozone plays two very different roles in global
environmental change: one in the stratosphere as a shield against harmful ultraviolet
radiation, and another nearer the ground in the troposphere as a greenhouse gas find a
health hazard.
The researchers hypothesized in 1974 that increasing concentrations of chlorofluorocarbons (CFCs), synthetic compounds that are chemically very stable in the lower atmosphere,
rise unchanged through the lowest atmospheric layer, the troposphere. Even though CFCs
are produced mostly in the industrialized countries of Europe and North America—where
they are used in a wide variety of applications such as for solvents and refrigerants.
The researchers surmised that upon reaching the stratosphere, the CFCs encounter
high-energy ultraviolet light’, which breaks them down, releasing their chlorine atoms. The
chlorine atoms can then engage with ozone in a catalytic reaction in which each chlorine
fragment can destroy up to 100,000 ozone molecules before other chemical processes remove
the chlorine from the atmosphere.
The Antarctic Ozone Hole
Now, many scientists describe the Antarctic ozone hole as the first unequivocal evidence
of ozone loss due to man-made chlorine and one of the first clearly definable effects of
human-induced global change. They found that the ozone levels dip at about the same
latitudes where levels of chlorine monoxide ascend. Scientists are convinced that the elevated
levels of chlorine and bromine account for much of the ozone depletion. The ozone molecules
are formed over the tropics and are delivered along with chlorine to the Antarctic, as well
as to the Arctic, via atmospheric motions. In Antarctica, a circulation pattern known as the
Antarctic polar vortex traps the ozone cover the South Pole for several months. It is within
this vortex that scientists have measured such shockingly low ozone concentrations during
the first two weeks of October shortly after the beginning of the Southern Hemisphere
spring. The chemical reactions that take place on these surfaces convert chlorine from forms
that do not react with ozone to other, less stable forms that readily break up in the presence
of sunlight and go on to destroy ozone. Both cold temperatures and sunlight arc critical to
the process leading to ozone depletion in the Antarctic. Antarctic ozone is depleted not
during the winter, when temperatures are coldest and the South Pole is immersed in darkness,
but in the southern spring, after sunlight returns but temperatures are still low.
Effect on Line
The ozone layer is essential to life because it shields it from damaging ultraviolet
radiation. Researchers are trying to learn how humans, vegetation, and aquatic ecosystems
each may be affected by ozone depletion. Direct exposure to ultraviolet radiation can damage
the human immune system, cause cataracts, and increase the incidence or skin cancer. The
EPA estimated in 1986 that the incidence of skin cancers would rise 2 percent for each 1
percent depletion of stratospheric ozone. As part of the effort to understand the effects on
vegetation and crops, researchers have tested more than 200 plant species, two-thirds of
which show sensitivity to increased ultraviolet exposure. Soybeans, one of civilization’s
staple food crops, are particularly susceptible to ozone damage, as are members of the bean
and pea, squash and melon, and cabbage families. Plant responses to ultraviolet radiation
include reduced leaf size, stunted growth, poor seed quality, and increased susceptibility to
weeds, disease, and pests. Scientists are also in the early stages of understanding how
ultraviolet radiation might affect marine ecosystems and animals. Concern about these
systems begins with phytoplankton, microscopic marine algae that form the base of the
marine food web. Studies in the tropics have shown that significant amounts of ultraviolet
radiation can kill them, while lesser amounts can slow photosynthesis and thus productivity.
In Antarctica, this could affect kill, tiny crustaceans a notch up the food chain, and then
fish, birds and marine mammals including seals and whales. While water provides some
protection from radiation, crude estimates indicate that ultraviolet radiation can penetrate
to depths of 10 to 20 meters. Some phytoplankton is known to be tolerant of ultraviolet
radiation, whereas others cannot tolerate any. A likely response will be for tolerant species
to replace sensitive ones, though no one knows how this would affect the fish that eat them.
Nations Joining to Protect the Ozone Layer
The Montreal Protocol on Substances That Deplete the Ozone Layer, negotiated in
September 1987, calls for 50 per cent reduction in CFC production from 1986 levels by 1999.
Forty-nine nations- including Canada, the United States Japan, and many nations in Europe,
which together consume 80 percent of the chemicals controlled-have ratified the protocol.
The protocol is a delicate balance between the most up-to-date scientific information, reliable
industrial expertise, and committed political leadership, all supported by strong and informed
public interest. The Montreal Protocol may prove to be a model for actions that span national
boundaries and interests as the world addresses common environmental issues such as
greenhouse warming and other forms of global change.
Conventions
Several conferences in the recent years have taken place which have provided
international policy framework to be considered when dealing with the science of the global
climate change as under:
Vienna Convention for the Protection of the Ozone Layer (Vienna, Austria, March 22,
1985). This convention was signed by 20 states and the EEC at a conference convened by
the UNEP. The object of the convention was the protection of human health and the
environment against adverse effect resulting or likely to result from human activities, which
modify or are likely to modify the ozone layer. International conference on the assessment
of the role of CO
2 and other green house gases in climate variations and associated impacts
(Villach, Austria, October 9- 15, 1985) and follow up workshops (Viliach, Austria, September,
28, October 2, 1987 Bellagio, Italy November 9-13, 1987). The Viuach conference held with
29 countries recommended that the- governments and intergovernmental organizations should
take into account the results of the assessment made in their environmental programmes,
and should favour the increase of public information effects on the global change issues.
This meet was in regard with the assessment of the presence of carbon’ dioxide in the
atmosphere.
Montreal Protocol on substances that deplete the Ozone Layer (Montreal, Canada,
September 16, 1987). This protocol signed by 24 of the 46 countries attending a Conference
in Montreal seeks to inhibit the production, consumption and trade of ozone-depleting
compounds. The compounds are divided into groups: Group I (certain CFSs) and Group II
(specific halons) each subject to different limitations. The protocol also distinguishes between
two groups of countries, the more developed with relatively high levels of consumption of
the contoured ozone depleting substances and the developing countries with relatively low
levels of consumption.
International Conference on the Protection of the Global Atmosphere (The Hague, The
Netherlands, March 11, 1989). This conference held at the initiative of the French Prime
Minister and co-sponsored by the French, Dutch, and the Norwegian governments, produced
“The Hague Declaration” which called for the development within the UN framework of a
new institutional authority, either by strengthening existing institutions or by creating new
institutions. The declaration also called for the creation of an “Atmospheric Fund” to provide
“fair and equitable assistance to compensate countries bearing and abnormal or special
burden as a result of decisions taken to protect the atmosphere.”
Earth Summit-United Nations Conference on Environment and Development (Rio de
Janeiro 3-14 June, 1992)- The historic Earth Summit held from June 3-14, 1992 in Rio de
Janeiro was attended by over 115 heads of states or governments. The major achievement
was the adoption of Agenda 21, a voluminous 800 pages document that details how countries
would go about achieving sustainable development with detailed chapters on the financial
principle and mechanisms involved. There are also chapter on technology transfers.

<<< Previous                                                             Next >>>
YamEen Uncategorized

6 Environmental science Social Issues part 1

IntroductionThe term sustainable was development and introduced by the World Commission onEnvironment and Development (The Brundtland Commission), in its seminal report of 1987,Our Common Future. The concept has terrifically worked out in creating public awarenessfor sustaining the planet with better management. The sustainable development has beendefined as “meeting the need of the present generation without compromising the needs offuture generation”. The concept precisely emphasizes upon using the earth resourcesjudiciously and compensating for it in some sense e.g. if cut few trees to support our lives,
we should also implant some new ones at some site. This would result in. maintaining the
earths fine balance between resource consumption and resource generation.
In understanding this concept we very often encounter two terms- sustainable and
development. These are summarized below as:
Sustainable
The literal meaning of sustainability is “that can be maintained” or “keep goal
continuously”. In ecological sense it refers to “conservation of ecological balance by avoiding
depletion of natural resources”. Hence, we can understand it as something, which has got
to do with longevity (long life) of a resource, commodity, species, ecosystem, earth etc.
Development
The literal meaning of development is “the act or instance of growth/advancement”. So
the growth can be of many types viz., growth of education, growth of industry, growth of
population, growth of forests and many other. But what type of growth are we addressing
to? Here we are addressing to one of the most sensitive issue of growing concern ‘about
improving the well-being of human beings. This could be achieved only through compromising
with some of our comforts and luxuries. The generation of comforts and luxuries brings
environment under great pressure. The Nations economic growth should not stand upon the
fragile foundation of earth’s resources. Mahatma Gandhi a great social scientist, rightly
192
CHAPTER
Environmental Science :
6 Social Issues
pointed out that, “The earth provides enough to satisfy everyone’s need, but not everyone’s
greed”.
In the context of economical and technical development the world always had been
better today than yesteryears and will always be better tomorrow than today. But the
condition of environment will always be poorer than before. Hence, the concept of sustainable
development raises certain questions for the present generations to answer. What is our
present? Are we happy with our present? Prospective changes of the magnitude described
above raises fundamental questions about the kind of world we will bequeath to our children
and about the nature and goals of development. The present in which we live is important
as it shapes our future. Nothing much can be done to recover the damages imposed on
nature in the past. But if we shape our surroundings based on environmental ethics and
economically exploit our present environment we would lend a healthier tomorrow to our
children. As we have examined some environmental issues in the previous chapters, we
would commonly agree that human population growth, loss of biodiversity, habitat destruction,
ozone depletion, global climate change, pollution (air, water, noise etc.) and limited food &
energy supply are environmental concerns of global scale. In the past two decades a great
deal of work from researchers, ecologists, environmental scientists, social scientists,
geographers and demographers have build up a very clear picture of what our tomorrow
would be like: Some initiatives have been taken up both at government and non-government
level. Still promising environmental concern at individual level is far lacking beyond
sustainable needs.
Although population growth continues to expand at an unsustainable pace but still
certain countries have achieved a demographic transition to zero population growth. However,
positive signs from developing nations are still absent. We have achieved breakthroughs in
renewable energy sources, agro-forestry schemes and better pollution control advancements.
Increased man awareness, resourcefulness and enterprise will help eliminate poverty and
resource wastage and will make our environment a much better place to live in. Until
environmental concerns do not find space in our heart we would never be able to delicately
handle our surroundings when we are at home or public. We should recognize things at
personal and collective grounds to protect nature and to create a sustainable environment.
Urban Problems Related to Energy
Big cities and towns have always influenced education, religion, commerce,
communication and politics, which have in turn influenced culture and society in various
proportions. Initially only a very limited section of the society lived in cities and towns while
the chief occupation of major population had been fishing, hunting, agriculture and cattle
rearing. However’ Industrial Revolution lead to expansion of cities and town both in size and
power. In developing nations, especially a large segment of society from villages moved to
cities for occupational support (occupational migration). This exactly was the cause of rapid
expansion of cities’ and formation of metropolitans like Delhi, Bombay, Chennai, Bangalore,
Calcutta and others. This ultimately brought into picture the concept of urbanization and
industrializations, which provided many benefits to society, especially to the rich, but also
introduced some evils in it. Here evils referred to were the increasing demand on energy
resources; whose consumption in turn lead to multitude problems of pollution, resource
shortage, diseases and waste disposal. Some of the major urban problems related to energy
are as under:
194 ENVIRONMENTAL SCIENCE
(i) Electricity
Electricity from various sources is a major requirement of expanding cities, towns and
villages. Each and every activity of mans life is now someway related to electricity
consumption. Housing gadgets like mixer-grinder, T.V., computer, music systems, geysers,
fans, lights, A.C.s, microwave, water lifting pump, warm blowers, coolers, etc. form the
essential components of a house. This all together has led to an electricity energy crunch.
It is well known that some part of electricity is lost in transmission and greater part
is stolen. The remainder is simply not enough to support the majority of people in the city
and that’s why the problem of electricity in cities is on the rise. The buildings are empowering
the cities like anything but nowhere we see dams, supplying electrical units, increasing in
number at the same pace. Therefore, what majority of the cities face today is a usual cut
of electricity for a minimum of 6-8 hrs. This makes today’s urban life handicapped. Resourceful
enjoy the resource benefit from the rising generator and inverter culture, which in turn put
pressure on resources and lead to pollution problems.
(ii) Fossil fuels (petroleum, natural gas and coal)
Fossil fuels have always been under a great threat from times immemorial. In the
absence of technological advancements these have served mankind for several years. In this
quest for energy the coal reserves have suffered a lot. With rise in technical know how man
started generating power from nuclear sources, hydroelectric power, wind power etc. But
still these contribute a little. We still depend on thermal power a lot.
(a) Petrol and Diesel: Transport and communication has brought the petroleum reserves
of the world under a great threat. The rise in number of vehicle per year is immense.
To understand the gravity of the problem a glance of metropolitan roads and lanes
is enough. Even the roads and lanes of big cities, small cities and towns are loaded
with two wheelers.
(b) Natural Gas: The common usage of natural gas is in the form of Liquid Petroleum
Gas (LPG). There is a terrific rise in the usage of LPG driven household commodities
with the expanding population. Earlier the LPG usage was only limited to kitchen
for cooking. The advent of technology introduced a numerous household items
making its use like gas geysers, gas heaters, gas fans, gas lanterns etc. In a way
it is serving as a substitute of electricity, which is other reason for increasing
pressure on oil wells/reserves.
(c) Coal: The world population has extracted and used coal reserves thinking as if it
is a never-ending commodity/resource. It has served Sustainable Development,
— Urban Problems,
— Water Conservation and Management,
— Resettlement and Rehabilitation of People,
— Environmental Ethics,
— Global Warning,
— Environment Protection Act,
— Issues involved in Enforcement of Environment Legislation,
ENVIRONMENTAL SCIENCE : SOCIAL ISSUES 195
Millions throughout the ages. Earlier it was primarily used to support kitchens. People
also utilized it for heating stoves/ heaters in colder regions of the world. Later, its usage in
the railways became the chief cause of its rapid exhaustion. Coal reserves are a limited
source of energy now. It should be used judiciously and economically.
(iii) Fuel wood
Fuel wood being used for the ignition of fire is chiefly responsible for the destruction
of impoverished forestlands. Though fuel wood collection to support family daily chores is
allowed in certain parts of the forest generally the outskirts but the greed and dearth
compels women to penetrate deep into the forest. Generally the big cities are characterised
by the absence of forestland at the fringes. But whatever degraded forest is available serve
as a source of fuel wood even in and around urban centres e.g. Dehradun is a well developed
city, but in its fringes we can still see women and children carrying loads of fuel wood.
Water Conservation
We could save as much as half of the water we now use for domestic purposes without
great sacrifice or serious changes in our lifestyles. Simple steps, such as taking shorter
showers, stopping leaks, and washing cars, dishes, and clothes as efficiently as possible, can
go a long way toward forestalling the water shortages that many authorities predict. Isn’t
it better to adapt to more conservative uses now when we have a choice than to be forced
to do it by scarcity in the future?
Rain Water Harvesting
Water is commonly taken for granted as nature’s gift. Often it is used wastefully in
agriculture, but industry and people pollute and poison available water supplies at an
alarming rate. Water problems arise from increasing demands generated by rapid population
growth; urbanization, industrialization and irrigation for additional food production. In many
areas excessive pumping of groundwater not only brings down water quality, but also depletes
it this affects’ sustainability. The ‘capacity of irrigation tanks numbering about five lakh in
the country is shrinking due to situation and encroachment. Scarcity is noticed even in high
rainfall areas like Cherrapunji (Assam), Western Ghats and Kerala. This is due to improper
management and poor conservation of rainwater.
India’s water potential is substantial but the scarcity is felt everywhere even for drinking.
This is because the country’s water policy and management is not very specific and
implementation is poor. Total rain in the country is about 400 M hm (million hectare
meters). The runoff in the rivers is estimated at 186 M ha. Further the utilizable groundwater
is calculated as 40 M hm. However, the utilizable quantity is about 110-115 M hm (70 M
hm from surface and 40 M hm from groundwater). To meet the relentless increase in
demand for water for various purposes and to achieve the goal of optimal use and to get the
maximum benefits, it is necessary to make water resource development holistic through a
comprehensive integrated river basin planning and management. This can be done only if
a wide range of disciplines are involved. Wastage of water due to leakage in pipes and
unattended repairs results in about 30-40 per cent water resource lost.
The landscape watershed units can be effectively subdivided into discrete hydrological
units. Since the watersheds are spatially laid from ridge to valley, they most efficiently
conserve land and water resources and help secure water availability throughout the growing
196 ENVIRONMENTAL SCIENCE
season. The land area of the watershed drains into a common point. Hence, the drainage
water can be easily stored in above -ground storage structures for recycling during droughts
or for growing an additional crop. Rain fed agriculture research and development has been
dominated by the concept of high yields for decades. It arose from the scientific principles
developed for the ‘green revolution’ high input, high-output technologies. Fatigue and cracks
are now developing in the green revolution areas. For rain fed agriculture, an area-based
development through watershed management provides an excellent framework for sustaining
semi-arid tropical ecologies. Also the landscape watershed units focus on the maintenance
of managed biodiversity through diversified cropping systems. It is significant to note that
a broad range of baseline information on watershed-based soil and water conservation
technologies already exists. A study commissioned by the National Institute of Agricultural
Extension Management, Hyderabad, showed that if the watershed technology is to succeed
it must be specific to natural endowments of the location; it must be built on indigenous
knowledge; it should be based on people’s participation; it must be equitable in sharing of
costs and benefits, and village-based institutions must be put-in-place right from inception
of the project.
Watershed Management
It was suggested that, rather than allowing residential, commercial, or industrial
development on flood plains, these areas should be reserved for water storage, aquifer
recharge, wildlife habitat, and agriculture. Sound farming and forestry practices can reduce
runoff. Retaining crop residue on fields reduces flooding, and minimizing. Ploughing and
forest cutting on steep slopes protects watersheds. Wetlands conservation preserves natural
water storage capacity and aquifer recharge zones. A river fed by marshes and wet meadows
tend to run consistently clear and steady rather than in violent floods.
A series of small dams on tributary streams can hold backwater before it becomes a
great flood. Ponds formed by these dams provide useful wildlife habitat and stock-watering
facilities. They also catch soil where it could be returned to the fields. Small dams can be
built with simple equipment and local labour; eliminating the need for massive construction
projects and huge dams. Watershed-based frame for rain fed agriculture provides uncommon
opportunities for achieving sustainable food and nutritional security. It is time that the
watershed development agenda is considered a programme for-the masses.
Resettlement and Rehabilitation of People
“Land for land” is a better policy than cash settlement. Even in implementing this
policy, the land is not given in the command area in most cases, forestland is either cleared
on waste fallow land given without any provision for developing the land or for the supply
of necessary inputs; a village is broken up and families dispersed; villagers are usually left
to buy private land, take loans from the government, which puts poor villagers at a
disadvantage- land prices in neighboring villages shoot up steeply if the government takes
up resettlement; the villagers are resettled in distant places, sometimes in a totally alien
environment and culture, thus creating insurmountable adjustment problems. Oustees from
Pong dam in Himachal Pradesh were settled in Anupgarh in Rajasthan, bordering on Pakistan.
The people were generally left to fend for themselves. Arrangements for drinking water,
dispensaries, schools, village roads or drainage of the rehabilitation sites are only completed
years later. In the case of the Ukai Dam in Gujarat, resettlement work was undertaken by
ENVIRONMENTAL SCIENCE : SOCIAL ISSUES 197
the ‘Ukai Nav Nirman Samity. Even so, out of a total of 18,500 affected families, only 3500
families could be resettled.
People who could previously barely manage to survive in their traditional environment
are uprooted as a result. The objectives of rehabilitation should be:
1. The people displaced should get an appropriate share in the fruits of development.
2. Creating new settlements with their own environment should rehabilitate them.
3. Removal of poverty should also be an objective of the rehabilitation policy and
therefore some land to all.
4. Oustees (even the landless) should be given assurance of employment.
5. While dealing with tribal one should also keep in mind the following five principles
of tribal-development accepted during Jawaharlal Nehru’s era as ‘tribal panchsheel.’
6. Tribal should develop along the lines of their own genius and we should avoid
imposing anything on them.
7. We should try to encourage their own traditional arts and culture in every way.
8. Resettlement should be in the neighborhood of their own environment. If
resettlement is not possible in the command area, top priority should be given to
the development of irrigation facilities and supply of basic inputs for agriculture;
drinking water, wells, grazing grounds for cattle schools for the children, primary
health care units and other amenities should be arranged.
9. In partly affected village, villagers should be given the option of shifting out with
others with the same compensation as available to evacuees.
10. Training facilities should be set up to upgrade the skills of affected people and
reservation in jobs should be made for the willing adults among the evacuees.
11. Special attention should be given to the rehabilitation of artisans and village crafts
people.
12. Villagers should be taken into confidence at every stage or implementation and
they should be educated, through open meetings and discussion about the legalities
of the Land Acquisition Act and other rehabilitation provisions.
13. The aid of voluntary agencies planning and implementation programme.
Rehabilitation Problem
Involuntary displacement of human population is always traumatic. Irrespective of the
causes leading to such migrations the degree of suffering experienced by such people simply
cannot be quantified in money values, and even in words it can be described only inadequately.
But, unfortunately, ousting of people likely to be submerged under irrigation or hydel power
dams is a classic case where hardships are imposed on people in spite of the ‘pro-people’
laws and policies proclaimed by the Government. Below is a critique of the Tehri Dam
Rehabilitation.
Compensatory Land
The project authorities commenced the Scheme by allocating 2767 acre of land in the
Dehra Dun area, which was already reeling under severe pressure from tourism, limestone
quarrying and urban expansion.

<<< Previous                                                             Next >>>
YamEen Uncategorized

5 Pollution and its Factors part 4

Disaster Management
Loss of life and property due to natural disasters like tropical cyclones, floods, droughts,
tornadoes, earthquakes, volcanic eruptions etc, is very large. Fortunately warning facilities
are available today and by mitigation measures, loss of lives and properties can be minimized.
National Meteorological Services of the world to provide warnings to the public for some of
the weather related natural disasters. It is not possible to forecast a long period ahead
precisely when and where a dangerous natural phenomenon will take place. While natural
disasters cannot be prevented, taking proper long-term and short-term disaster mitigation
measures can minimize the loss of life and property.
Some common disasters known to occur in our country are as under:
Floods
Floods are defined as a relatively high flow of water discharged from river and stream
network, which sets the riverbank margins to overflow and lead to the inundation of low
land areas surrounding the riverbed. It is essentially a physical phenomenon. Floods arise
from abnormally heavy rains, dam failures, snow melts, river blockages. Flood disasters
rank second only to droughts in the total number of people affected worldwide.
Types of Floods
Floods can be classified into three categories as under:
(i) River floods
Rivers get charged due to heavy rains over large catchments areas or by melting of
snow or sometimes both especially in the mountainous tracts. The floods take place in river
systems with tributaries that may drain into large geographic areas and encompass many
independent river basins. Amount of flooding depends on moisture in the soil, vegetation
cover, and depth of snow and size of catchments basin.
(ii) Coastal floods
Coastal flooding is associated with tropical cyclones/ harsh winds arising at the ocean
surface. Coastal floods are often aggravated by wind induced storm surges along the coastline.
Sea and ocean ‘water floods the inland coasts affecting kilometers of tracts. Ocean tides,
storm surges or tsunamis play a definite role. Prolonged and indefinite rains in the rainy
season marked from June-September results in extreme flood in coastal river basins.
(iii) Flash floods
These floods occur within six’ hours of the beginning of rainfall and; are characterized
with rising clouds, thunderstorms and tropical cyclones. These result from runoff from a
torrential downpour, particularly if the catchments slope is unable to absorb and hold a
significant part of water. Other causes of flash floods include dam failure, sudden break up
of glaciers etc. These offer potential threats in the areas where the terrain is steep, surface
runoff is high, water flows through canyons and where severe rainstorms are likely.
General Characteristics of Floods
1. Man made structures and forest vegetation exhibits different levels of tolerance
towards effects of floods.
2. Intensity of damage is governed by the time interval of standing floodwaters.
3. High velocity of running water may uproot or weaken foundations of buildings.
4. Rate of rise and discharge of a river is important as a basis for flood control.
5. Frequency of occurrence estimated over a length of period would determine the
kind of activities the flood plain should be put to.
6. Generally the rainy season is characterized by the floods during which agricultural
economy suffers a huge loss.
Effects of Floods
1. Rising water, erosion and the force damages the residential and commercial building.
They are dangerous for villages lying in the coastal areas as it sweeps away
everything, which comes into its path. In mountainous areas it is the chief cause
of landslides.
2. Fisherman, local people, cattle, animals and vegetation suffer a great loss of life
and property. Most of the deaths are reported to be from drowning.
3. Fresh water supplies by all sources are nearly destroyed and contaminated hence
the areas falling under its impact bear a great risk of suffering from water borne
diseases.
4. The destruction of food and fodder crops result in acute food shortage.
5. Floods also make soil infertile, as the topsoil is lost due to erosional activity.
6. Floods are also known to preserve, wetlands and recharge ground water.
Flood Control
1. Depth and width of the riverbed could be increased as its capacity to carry larger
loads increases manifold and thus reduce the area of the flood plain.
2. A network of canals can be established from the river systems, which generally
leads to floods. This would also benefit the agricultural economy/ section. Care
must be taken in the design and construction because of the possible environmental
impact and necessary safety features.
3. Reservoirs should be made for storing floodwater and releasing them at manageable
rates. This would require careful engineering. Dams, and reservoirs would further
lead to generation of resources.
4. Newly constructed residential as well commercial buildings should have foundations,
which are strong enough to respond to flood conditions.
5. Rivers and streambeds should be stabilized with stone, masonry or vegetation at
the banks. This should strictly be followed where rivers pass through cities, specially
near bridges.
Post Disaster Requirements
The initial response to flooding authorities/community should include:
Search and Rescue operations, water provision,
Medical assistance, Disaster epidemiological surveillance assessment, food and
and temporary shelter.
The secondary response should include:
Reconstruction of houses, equipment and tools, supply
Creation of employment, of animals, and assist with
Assistance to farmers, recovery of small business
Distribution of farm and fisheries.
Flood Problem In India
The nature of flood problem varies from one river system to another. Two great river
systems are discussed below considering the flood problems in India:
Brahmputra River
The main problem of flooding in the northeastern region arises from the Brahmaputra
river and its tributaries. The river in monsoon season overflows its banks and causes a great
damage to life and property both. Several times it has affected Kaziranga wildlife sanctuary
where rhinoceros population died due to rising floods. In recent years, the erosion along the
banks of the Brahmputra has assumed serious proportions. The rivers also carry considerable
amount of silt and have a tendency to change its course.
Ganga River System
In this region the northern tributaries of the Ganga, namely the Rapti, the Sharada,
the Ghaghra and the Gandak cause extensive flooding along their banks. Drainage congestion
is confined to the northwestern parts of U.P., Meerut, Mathura and Agra suffers the most.
Bihar suffers a considerable amount of damage due to the flooding of the Burhi Gandak, the
Baghirati, the Kamla Balan, the Kosi and the Mahananda. In addition to the crop submergence
the area experiences traffic dislocation also. In the Bengal region Baghirati, the Ajoy and
the Damodar cause extensive flooding. Here the tidal effect of Bay of Bengal also plays a
role in flooding. In Delhi and Haryana it is the Yamuna, the biggest tributary of the Ganga,
which causes a marginal amount of flooding. Most of these flooding regions suffer from
inadequate channel capacity as well as regulation of river water flow in these channels.
Earthquakes and Seismology
An earthquake is a major demonstration of the power of the tectonic forces caused by
endogenetic thermal conditions of the interior of the earth. An earthquake is a motion of the
ground surface, ranging from a faint tremor to a wild motion capable of shaking buildings
apart and causing gaping fissures to open in the ground. The Richter scale devised by
Charles F. Richter in 1935 measures the magnitude or intensity of energy released by an
earthquake. Good Friday Earthquake of March 27, 1964 in Alaska (USA) measuring 8.4 to
8.6 on Richter scale is among the greatest earthquakes of the world ever recorded.
The science that studies the behaviour and patterns of seismic waves is called seismology.
The place of origin of an earthquake is called focus, which is always hidden inside the earth,
but its depth varies from place to place. The place of the origin of an earthquake is called
‘focus’ which is always hidden inside the earth. The deepest earthquake may have its focus
at a depth of even 700 km below the ground surface. Major Himalayan earthquakes, such
as the Bihar-Nepal earth quake of August 2, 1988, have their focus around 20-30 km deep.
The place on the ground surface, which is perpendicular to the buried ‘focus’ or ‘hypocenter’
recording the seismic waves for the first time is called ‘epicenter’. The waves generated by
an earthquake are called ‘seismic waves’ which are recorded by an instrument called
seismograph. The lines joining the places of equal intensity of seismic waves on the maps
are called is oseismallines.
Causes of Earthquakes
Earthquakes are caused mainly due to disequilibria in any part of the crust of the
earth. A number of causes have been assigned to cause disequilibria in the earth’s crust such
as volcanic eruptions, faulting and folding, gaseous expansion and contraction inside the
earth, hydrostatic pressure of man-made water bodies like reservoirs and lakes, and plate
movements.
(1) Vulcan City
Volcanic activity is considered to be one of the major causes of earthquakes. Vulcan city
and seismic events are so intimately related to each other that they become cause and effect
for each other. Earthquakes follow each volcanic eruption and many of the severe earthquakes
cause volcanic eruptions. The explosive violent gases during the process of Vulcan city try
to escape upward and hence they push the crystal surface from below with great force and
thus is’ caused severe earth tremors of high magnitude.
(2) Faulting and Elastic Rebound Theory
The horizontal and vertical movements caused by end genetic forces result in the
formation of faults and folds which in turn cause isocratic disequilibria in the crystal rocks
which ultimately causes earthquakes of varying magnitudes depending on the nature and
magnitude of dislocation of rock blocks caused by faulting and folding. The 1950 earthquake
of Assam was believed to have been caused due to disequilibria in crystal rocks;
(3) Hydrostatic Pressure and Anthropogenic Causes
Certain human activities such as pumping of ground water and oil, deep underground
mining, blasting of rocks by dynamites for constructional purposes, nuclear explosion, storage
of huge volume of water in big reservoirs etc. also cause earth tremors of serious consequences.
The introduction of additional load through the construction of large dams and impounding
of enormous volume of water in big reservoirs behind the dams cause disequilibria of adjusted
rocks below the reservoirs.
(4) Plate Tectonic Theory
The earth is composed of solid and moving plates having either continental crust or
oceanic crust or even both continental oceanic crusts. The earth’s crust consists of 6 major
plates (Eurasian plate, American plate, African plate, Indian plate, Pacific plate and Antarctic
plate) and 20 minor plates. These plates are constantly moving in relation to each other due
to thermal convective currents originating deep within the earth. All sorts of disequilibria
are caused due to different types of plate motions and consequently earthquakes of varying
magnitudes are caused.
CLASSIFICATION OF EARTHQUAKES
Each earthquake differs from the other and thus it becomes difficult to classify all the
earthquakes into certain categories.
(1) Classification on the Basis of Causative Factors
(A) Natural Earthquakes are those, which are caused by natural processes i.e. due
to end genetic forces. These are further divided into four subcategories.
(i) Volcanic Earthquakes are caused due to volcanic eruptions of explosive
and fissure types and are confined to volcanic areas. Severe earthquake
caused by violent explosions of Etna volcano in 1968.
(ii) Tectonic Earthquakes are caused due to dislocation of rock blocks during
faulting activity. Such earthquake is very severe and disastrous i.e. 1906
earthquake of California (USA).
(iii) Isostatic Earthquakes are triggered due to sudden disturbance in the
Isostatic balance at regional scale due to imbalance in the geological processes.
(iv) Plutonic Earthquakes are in fact, deep focus earthquakes, which occur at
greater depths.
(B) Anthropogenic Earthquakes are caused by human activities such as pumping of
water and mineral oil from underground aquifers. and oil reserves respectively,
deep underground mining, blasting of rocks by dynamites for constructional purposes
e.g. Koyna earthquake of Maharashtra of 1967 due to Koyna reservoir etc.
(2) Classification on the basis of Focus
On the basis of the depths of their foci these have been divided into 3 types.
(i) Moderate Earthquake: Foci are located at the depths between 0-50 km.
(ii) Intermediate Earthquake: Foci at the depths between 50-250 km.
(iii) Deep Focus Earthquake: Foci at the depths between 250-700 km.
Classification on the basis of Human casualties
(i) Moderately Hazardous Earthquakes: If deaths of human range below 50,000
due to seismic tremors e.g. Tabas earthquake of Iran 1978 A.D. (death toll 25,000).
(ii) Highly Hazardous Earthquakes: If deaths of human range between 51,000-
1,00,000 due to seismic tremors e.g. in 1935, Quetta, Baluchistan, (death toll
60,000).
(iii) Most Hazardous Earthquakes: If deaths of human casualties are above 1,00,000
mark e.g., in 1976 Tang-Shan, China (death toll 7,50,000).
World Distribution of Earthquakes
Earthquakes are, in fact associated with the weaker and are statically distributed areas
of the world. Most of the world earthquakes occur in the zones of young folded mountains,
the zones of faulting and fracturing, the junction of continental and oceanic margins, the
zones of active volcanoes and along the different plate boundaries. The world map of the
distribution of earthquakes prepared by seismologists show the occurrence of earthquakes
along the following belts.
(i) Circum-Pacific Belt: surrounding the Pacific Ocean.
(ii) Mid-Continental Belt: representing epicenters located along the Alpine-Himalayan
Chains of Eurasia and northern Africa and epicenters of East African Fault zones.
(iii) Mid Atlantic Belt: representing the earthquakes located along the mid-Atlantic
Ridge-and its offshoots.
Effects of Earthquake hazardous
Earthquakes and their hazards are determined on the basis of the magnitude of seismic
intensity as determined by Richter scale but are decided in the basis of quantum of damages
done by a specific earthquake to human lives and property.
(i) Landslides
Weaker landmasses and tectonically sensitive land margins cause landslides and debris
falls, which damage settlements and transport systems on the lower slope segments.
(ii) Damage to Life and property
Structures such as buildings, roads, rails, factories, dams, bridges suffer a huge damage
thus causing a heavy loss of human life and property both. The vibrations of earthquakes
last longer and the amplitudes of seismic waves are greater artificially in filled and leveled
depressions, swamp deposits etc. than in the structures of consolidated materials and bedrocks.
Two major earthquakes of Bihar-Nepal border in 1934 and 1988 explain the impact of
earthquake disasters on human structures and human lives. The damage caused by the
Bihar earthquake of 15 January 1934, measuring 8.4 on Richter scale, include 10,700 human
deaths, landslides and slumping in an area of 250 km length and 60 km width, ruptures and
faults in the ground surface etc.
(iii) Damages to Government Infrastructure
Cities and towns are worst affected due to large concentration of human population,
commercial complexes and residential areas. Due to collapse of large buildings there is
greater loss of life and property. Due to collapse of buildings ground water pipes are bent
and damaged thus water supply is disrupted, electric and telephone poles are uprooted and
there is total disruption of power and communication. Other side effects are collapsed sewer
system causing epidemics, roadblocks etc.
(iv) Fire Hazard
Earthquakes strongly shake the buildings and thus strong oscillations cause severe
fires in houses, mines and factories because of overturning of cooking gas cylinders, contact
of live electric wires, churning of blast furnaces, displacement of other electric and firerelated appliances.
(v) Landmass Deformation
Severe earth tremors and resultant, vibrations caused by severe earthquakes result in
the deformation of ground surface because of crusts and troughs in the ground surface and
faulting activity.
(vi) Flash Floods
Strong seismic events result in the damages of dams and cause severe flash floods.
Severe floods are also caused because of blocking of water flow of rivers due to rock blocks
and debris produced by severe tremors on the hill slopes facing the river valleys.
(vii) Tsunamis
The seismic waves, caused by the earthquakes traveling through seawater, generate
high sea waves and cause great loss of life and property. Since the pacific Ocean is girdled
by the earthquakes and volcanoes tsunamis are more common in the pacific with a minimum
frequency of 2 tsunamis per year.
A CASE STUDY
U.P. Earthquake of 1991
A severe earthquake occurred in Garhwal region of Uttar Pradesh on 20th Oct. 1991.
Intensive tremors were felt at 2.53 a.m., which lasted for about 45 seconds. The magnitude
of earthquake was measured 6.6 on Richter scale and its epicenter was at Angola, a place
near Uttarkashi, Mild tremors are a regular feature of the area. The worst affected areas
have been in the district of Uttarkashi, Tehri Garhwal and Chamoli while it also caused
sizeable damage in the districts of Dehradun, Pauri Garhwal and Nainital. The roads and
bridges are the chief means of communication in hill region, which underwent heavy damage.
The economy of such places is based on tourism to a great extent, which suffered a great
set back. The overhead drinking tanks and pipelines had developed cracks. Sources of
drinking water had been damaged. The earthquake caused intensive damage to the building
of various government departments, Forest, Home, Finance and Rural Development.
Cyclones
Cyclones are the centers of low pressure surrounded by closed isobars having increasing
pressure outward and closed air circulation from outside towards the central low pressure
in such a way that air blows inward in anticlockwise on northern hemisphere and clockwise
in southern hemisphere. They range in shape from circular, elliptical to V shape. From
locational viewpoint cyclones are classified into two principal types e.g. i) extra-tropical
cyclones/temperate cyclones ii) tropical cyclones.
(I) Temperate Cyclones
Temperate cyclones are atmospheric disturbances having low pressure in the centers
produced in the middle latitudes characterized by converging and rising air, cloudiness and
precipitation. They are formed in the regions extending between 350- 65″ latitudes in both
hemispheres due to convergence of two contrasting air masses e.g. After their formation
temperate cyclones move in easterly direction under the influence of westerly winds and
control the weather conditions in the middle latitudes.
(i) Shape, Size and Speed
Temperate cyclones are of different shapes e.g. circular, semi-circular, elliptical, elongated
or V, but all of them are characterized by low pressure in their centres and closed isobars.
The pressure difference between the centre and periphery is about 10-35 mb. It means that
pressure increases from the centre towards outer margin. Average large diameter of an
ideal cyclone is about t 900 km while short diameter measures t 000 km. The temperate
cyclones move eastward under the influence of westerly winds with average velocity of 32
km per hour in summer and 48 km per hour in winters.
N.W. Quadrant N.E . Q uadrant
Cold front
S.W. Q uadrant
S.E. Q uadrant
Figure 5.1: A generalized temperate cyclone in northern hemisphere.
(ii) Wind Systems
Since there is low pressure in the centre of temperate cyclone and air pressure increases
outward and hence winds blow from the periphery towards the centre but these winds do
not reach the centre straight rather they cut the isobars at the angle of 20° to 400 due to
friction and Coriolis force and thus wind direction becomes anticlockwise in the northern
hemisphere and clockwise in the southern hemisphere. Since temperate cyclones are formed
due to convergence of two contrasting air masses and hence it is natural that there are
variations in the nature and direction of winds in different parts of the cyclones.
(iii) Temperature
Different temperatures are noted in different parts of temperate cyclones because of
their origin due to convergence of two thermally contrasting air masses. The southern part
of cyclone records higher temperature because of the dominance of warm air while the
north-eastern, northern and north-western parts record low temperature because of the
dominance of cold polar air mass. The western part records lowest temperature.
(iv) Source Regions and Tracks of Movement
The areas frequented by temperate cyclones mostly lie in the middle and high latitudes
extending between 350-650 latitudes in both the hemispheres. These cyclones move, on an
average, in easterly direction. (1) Cyclones after originating in the north Pacific off the
north-east and eastern coasts of Asia move in easterly and north-easterly direction towards
the Gulf of Alaska and ultimately merge with Aleutian Lows from where they follow southerly
direction and reach as far south as southern California. The cyclones moving inland dissipate
and are occluded at the windward western slopes of the Rocky Mountains.
(v) Origin of Temperate Cyclones
Though the formation and development of temperate cyclones is a quick process but it
passes through a series of successive stages. The period of a cyclone from its inception
(cyclogenesis) to its termination (proteolysis or occlusion) is called the ‘life cycle of cyclone’;
which is completed through six successive stages.
(a) The first stage involves the convergence of two air masses of contrasting physical
properties and directions. Initially, the air mass (warm and cold) move parallel to
each other and a stationary front is formed. This is called initial stage.
(b) The second stage is also called as ‘incipient stage’, during which the warm and
cold air masses penetrate into the territories of each other and thus a wave-like
front is formed.
(c) Third stage: This is the mature stage when the cyclone is fully developed and
isobars become almost circular.
(d) Fourth stage: Warm sector is narrowed in extent due to the advancement of cold
front than warm front, as cold front comes nearer to warm front.
(e) Fifth stage: Starts with the occlusion of cyclone when the advancing cold front
finally overtakes the warm front and an occluded front is formed.
(f) Sixth stage: Warm sector completely disappears, occluded front is eliminated and
ultimately cyclone dies’ out.
(II) Tropical Cyclones
(i) General Characteristics
Cyclones developed in the regions lying between the tropics of Capricorn and Cancer
are called Tropical Cyclones which are not regular and uniform like extra tropical or temperate
cyclones. There are numerous forms of these cyclones, which vary considerably in shape,
size, velocity and weather conditions. The weather conditions of low latitudes mainly rainfall
regimes are largely controlled by Tropical Cyclones.
(a) Size of tropical cyclones varies considerably. On an average their diameters range
between 80 km and 300 km.
(b) Weak cyclones move at the speed of about 32 km per hour while hurricanes attain
the velocity of 180 km per hour or more.
(c) Tropical cyclones become more vigorous over the oceans but become weak and
feeble while moving over land areas. This is why these cyclones affect only the
coastal areas e.g. Tamil Nadu, Orissa and West Bengal coasts of India.
(d) The centre of the cyclone is characterized by extremely low pressure.
(e) Tropical cyclones are not characterized by temperature variations in their different
parts because they do not have different fronts.
(f) There are no different rainfall cells hence each part of the cyclones yields rainfall.
(g) Tropical cyclones are not always mobile. Normally, they move from east to west
under the influence of trade winds
(h) Tropical cyclones are confined to a particular period of the year (summer season).
(ii) Types of Tropical Cyclones
Generally they are divided into 4 major types
(a) Tropical disturbances or easterly waves
(b) Tropical depressions
(c) Tropical storms
(d) Hurricanes or typhoons
(iii) Origin of Tropical Cyclones
On an average, tropical cyclones are formed due to development of low pressure of
thermal origin. They develop when the following requirements are fulfilled:
(a) There should be continuous supply of abundant warm and moist air. Tropical
cyclones originate over warm oceans having surface temperature of 27°C.
(b) Higher value of Coriolis force is required for the origin of these cyclones.
(c) They are associated with inter-tropical convergence (lTC), which extends from 50
-300N latitudes during summer season.
(d) There should be anti-cyclonic circulation at the height of 9000 to 15000 m above the
surface disturbance.
(iv) Distribution of Tropical Cyclones
There are 6 major regions of the tropical cyclones e.g. (1) West Indies, Gulf of Mexico,
and Caribbean Sea. (2) Western North Pacific Ocean including Philippines, Islands, China
Sea, and Japanese Islands. (3) Arabian Sea and Bay of Bengal. (4) Eastern Pacific coastal
region off Mexico and Central America. (5) South Indian Ocean of Madagascar (Malagasi),
and (6) Western South Pacific Ocean, in the region of Samoa and Fiji Island and the east
and north coasts of Australia.
(v) Environmental Impact of Tropical Cyclones
Tropical cyclones are very severe disastrous natural hazards which inflict heavy loss to
human lives and property in terms of destruction of buildings, transport systems, water and
power supply systems, disruption of communication system, destruction of standing
agricultural crops, domestic and wild animals, natural vegetation, private and public
institutions etc. Through damages caused by high velocity winds, floods and storm surges.
ANTICYCLONES
General Characteristics
Surrounded by circular isobars anticyclone is such a wind system which has highest air
pressure at the centre and lowest at the outer margin and winds blow from the centre
outward in clockwise direction in the northern hemisphere and anticlockwise in the southern
hemisphere fig.13. Thus, anticyclones are high-pressure systems and more common in the
subtropical high pressure belts but are practically absent in the equatorial regions.
Anticyclones were classified into (i) warm anticyclones, and (ii) cold anticyclones by
Hanzilk in 1909.
They are characterized by the following properties.
(1) They are usually circular in shape. The difference of pressure between the centre
and periphery of anticyclone ranges between 10-20 mb.
(2) They are much larger in size and area than temperate cyclones.
(3) Anticyclones follow cyclones. They move very sluggishly. The average velocity of
anticyclones is 30-50 km per hour.
(4) Winds descend from above at the centre and thus weather becomes clear and rain
less because the descending winds cause atmospheric stability.
(5) Temperature in anticyclones depends on weather, nature of air mass and humidity
in the air.
(6) Anticyclones do not have fronts.
1. Wind Systems and Temperature
Wind system is not fully developed in anticyclones because of weak pressure gradient.
On an average, wind circulation is of divergent system wherein winds spread in all directions
from high-pressure centre to low-pressure periphery. The winds are very much sluggish in
the rear portion in comparison to the front portion. The centre is characterized by light
breeze.
These arise due to the descent of either polar cold air mass or warm tropical air mass.
Cold anticyclones are associated with extremely low temperature and they cause cold waves
during winter season but when they come in summer season, weather becomes pleasant.
2. Shapes and Size
Anticyclones are generally of circular shape but are very large in size. They become so
large in size that their diameters become 9,000 km.
3. Weather ConditionsGenerally, anticyclones are rainless and sky is free of clouds because of the fact thatdescending air in the centre of anticyclone is warmed up at dry adiabatic rate due tosubsidence. This causes rise in temperature, which reduces normal lapse rate of temperature,with the result the stability of air increases resulting into marked increase in the aridity of
air. This is why anticyclones are indicative of dry weather.
4. Landslides
Among physiographic units, the two northern units of the Greater Himalayas (7500-
8500m), and the Inner Himalayas (Trans-Himalayan zone), an intervening system of high
plateau and valleys lying between the two great mountain ranges, are considered along with
middle mountains, the traditional centres of population. The upper northern section of these
middle mountains remains largely’ under upper montane forest (2900-4000 m), below which
is the belt of intensive agriculture. Lithology is highly varied, including sedimentary,
metamorphism, and granites. However, there are extensive areas of phyllites and schists;
these are deeply weathered and the prevailing steep slopes render them highly susceptible
to erosion and slope failure (mostly through landslides). Presently, according to gross yet
reliable estimate, the landslides occupy about 1% of land surface in only five central districts
of Himachal Pradesh. They have a total volume of more than 2.2 x 106 m3 and a mean age
of 6.5 years. This helps to evaluate the denudation rate, which is about 12 mm/year (all
erosive processes). Landslides have about 2.5-mm/ year denudation rates. One of the main
causes of landslides is road construction.
Suggestions
Various studies indicate that for each linear kilometer of mountain road, 10 small to
medium landslides occur. Prior to the 1962 border war with China, the Himalayan section
in India was in most parts accessible only on foot. The shock of the Chinese military
presence, the three India-Pakistan wars of 1947, 1965, and 1971, the continued border
tensions (especially along the Kashmir ceasefire line), and several other problems led to
accelerated construction of up to 10,000 km of highways and connecting roads. The poor
alignment and ill-considered design are causing a total soil loss of 0.199 t of sediment per
linear meter of road per annum. Valdiya (1973) indicated that during the construction phase
an average kilometer of road requires the removal of 40,000-80,000 m3 of debris. These
enormous volumes are dumped on the roadsides and damage ecologically fragile slopes by
depriving them of natural vegetation and at times destroy the terraces.
QUESTIONS
1. Write the definition of pollution in your own words and also explain the causes of pollution.
2. Explain the types of pollution. Write the precautions to minimize the pollutions (air, water,
social, marine, noise).
3. What is social water management? Explain.
4. Explain the role of an individual in prevention of pollution and how it is possible?
5. How we can conduct the pollution case study in a particular area and also explain the
disaster management?
<<< Previous 

YamEen Uncategorized

5 Pollution and its Factors part 3

Effect of Noise Pollution
1. Constant noise affects a man physically and mentally. Physical effects include
blood vessels to contract, skin to become pale, muscles to constrict and rise in blood
pressure leading to tension and nervousness.
2. High intensity sound emitted by industrial plants, bottling machines, supersonic
aircrafts, when continued for long periods of time not only disturbs but also
permanently damages hearing.
3. Offices, industries and crowded places where constant noise prevails can produce
temper tantrums, headaches, fatigue and nausea. 
4. Loud and sudden noise affect the brain. Intermittent noise leads higher incidence
of psychiatric illness and also a danger to health of pregnant mothers and small
infants.
5. Noise has harmful effects on nonliving materials too, e.g. cracks develop under the
stress of explosive sound.
Control of Noise Pollution
Following methods can control noise pollution:
1. Limited use of loudspeakers and amplifiers.
2. Excursing control over noise producing vehicles.
3. Industrial workers should be provided with ear plugs.
4. Delocalisation of noisy industries far away from dwelling units.
5. Within a radius of 10 miles of airport, no buildings or factories should be allowed.
6. Plants and trees should be planted all around the hospitals, libraries and schools
and colleges.
7. Personal protection against noise can be taken by using, cotton plugs in the ear.
Radiation
The radiations from the atomic blasts cause several health hazards. The radiations
carry high energy and remove electrons from atoms and attach them to other atoms producing
positive and negative ion pairs. Hence, they are known as ionizing radiations. The ionization
property of these radiations proves to be highly injurious to the protoplasm. The ionizing
radiations of ecological concern are classified as follows:
Corpuscular Radiations
These consist of streams of atomic or subatomic particles, which transfer their energy
to the matter they strike.
(i) Alpha particles
These particles are large and travel few centimeters in the air. These cause large
amount of local ionization.
(ii) Beta particles
These are small particles characterized by having high velocities. They can travel a few
meters in space. These are capable of entering into the tissues for few centimeters.
Since alpha and beta particles have low penetration power they can produce harmful
effects only when absorbed, ingested or deposited in or near living tissues.
(iii) Electromagnetic radiations
Electromagnetic radiations include waves of shorter wavelengths. These are capable of
traveling long distances and can readily penetrate the living tissue. These include gamma
rays. These can penetrate and produce effect even without being taken inside.
Other Types of Radiations
Besides radioactive radiations, some other radiations are also present in the atmosphere
(i) Neutrons
These are large uncharged particles, which do not cause radiation by themselves, but
they produce radioactivity in non-radioactive materials through which they pass.
(ii) X-rays
These are electromagnetic waves very similar to gamma rays, but originate from the
outer electron shell of radioactive substances, which are not dispersed in nature.
(iii) Cosmic rays
These are radiations from the outer space, which contain alpha and beta particles
together with gamma rays.
Sources of Radiations
The radiations are produced from the radioactive elements, which are known as
radionuclides or radioactive isotopes, e.g. Uranium. Radium, Thorium, and Carbon-14. These
contribute to background radiation. But isotopes of certain metabolically important elements
like Carbon-14, Cobalt-60, Calcium 45, Iodine-131, Phosphorus-32, etc. are not ecologically
harmful but are used as tracers. The third category of radionuclides comprises of fission
products of uranium and certain other elements. These are cesium, strontium, and plutonium
etc.
Biological Effects of Radiation
The effects of radiation have revealed that acute doses are found to be deleterious and
may kill the organisms, whereas the increase in radiation in biological environment leads
to different kinds of mutations. The effects of Cobalt-60 or Cesium-137 gamma radiations
have now been studied on communities and on ecosystems at different places. The research
concludes that Irradiations eliminate varieties in species. The sensitivity of cells, tissues and
organisms to radiation varies. The cells with larger chromosomes are more sensitive.
Herbaceous communities and early stages of succession are resistant than the mature forest.
Nuclear Fall Outs or Radioactive Fall Outs
The atomic blasts not only produce the local ionizing radiations at that time but the
radioisotopes produced as a result of explosion enter the atmosphere and continue to fallout
gradually over broad geographic areas for a very long time. These are known as nuclear
fallout or radioactive fallout. These are dangerous for life as they also produce ionizing
radiations.
Biological Effects of Fall outs
The fallout of radionuclides combines with various metals and dust and from colloidal
suspension combines with organic compounds to form complexes. The smaller particles of
radionuclides adhere tightly to the leaves of plants and produce radiation damage to leaf
tissue besides entering the tissues also. Through grazing animals these enter the food chain
directly at the primary consumers level. Radionuclides, which combine with organic
substances, enter the food chain through producer tropic level. Therefore, the radionuclides
fall out manages to enter the body of all living organisms. Radioactive Strontium-90 poses
a health hazard in human beings and other higher vertebrates. It continues to deposit in
the bones and causes bone cancer and leukemia. Radioactive Cesium-137 is known to cause
irreversible genetic changes in different organisms. The fallout radiations do cause changes
in the genetic constitution of organisms, resulting in gene mutations and chromosomal
aberrations. Their considerable, doses may kill, cripple and alter the animals and plants in
the areas.
Control of Radiation Pollution
Following measures can help in controlling the radioactive pollution:
(i) Workers in nuclear plants should be provided with nuclear gadgets and safety
measures against accidents.
(ii) Leakage of radioactive elements from nuclear reactors, laboratories, transport,
careless handling and use of radioactive fuels should be checked.
(iii) Level of radiation pollution should be monitored regularly in risk areas.
(iv) Disposal of radioactive wastes deserves special attention.
Case studies
Hiroshima and Nagasaki Episode
The tale of Hiroshima and Nagasaki is a painful experience. It is for the first time that
an atomic bomb has been exploded over human population. The incident took place on
August 6,1945 at 8:15 a.m. The bomb with an approximate temperature of around 100
million 0°C was exploded on a fine morning in Hiroshima (Japan). The temperature of the
city hiked like anything, almost like an oven. After three days, Nagasaki too suffered the
ravages of a nuclear attack. More than 1,00,000 people were reported to die just after the
event took place. Since radiations from nuclear elements remain active even after, the
generations to follow up also suffered from various diseases. Even the babies in the mother’s
womb were affected and a few perished. Blindness, deafness, skin diseases and cancers,
distortion of bones and other parts became the fortune of human civilization.
Chernobyl Accident
This incident took place in Ukraine on April 26, 1986. There was a Chernobyl nuclear
power plant in Ukraine after which the event has been named. Approximately four million
people had been reported to suffer from the accident. The accident contaminated neighboring
environment up to several kilometers. The sites were evacuated and resettlement was done
for the affected people. The radiations released affected ground water and surface waters,
affecting large areas of Europe. 131 Iodine and 137 Cesium are the most dangerous amongst
the 20-odd radioactive elements released during Chernobyl disaster. As per the Soviet Health
Ministry, 31-persons died shortly after the disaster. Of the 276,614 people who worked for
rehabilitation and cleaning operations, a total of 1065 died by the end of 1990.
Marine Pollution
All river drainages end up in the seas. On the way to sea, rivers carry large amounts
of sewage, garbage, and agricultural discharge, biocides, including heavy metals. Besides
this discharge of oils and petroleum products and dumping of radionuclides waste into sea
also cause marine pollution. Huge quantity of plastic is being added to sea and oceans. Over
50 million lb plastic packing material is being dumped in sea of commercial fleets. Many
marine birds ingest plastic that causes gastro-intestinal disorders. The chemical principle in
PCBs causes more damage as thinning of eggshell and tissue damage of egg. Radionuclide
waste in sea includes Sr-90, Cs-137, Pu-239, and And Pu-240.
The pollutants in sea may become dispersed by turbulence and ocean currents and
finally becomes a part of food chain. Bioaccumulation in food chain may result into loss of
species diversity. The pollution in Baltic sea along the coast of Finland, took place largely
from sewage and effluents from wood industries. This pollution effect brought changes. in
species diversity in the bottom fauna. In less polluted water there was rich species diversity,
which tended to decrease with increasing pollution load. In heavily polluted areas, macroscopic
benthic animals were absent, but chirognomy larvae occurred at the bottom. In marine
water the most serious pollutant is oil. Spill of oil or petroleum products due to accidents/
deliberate discharge of oil polluted waste brings about pollution. About 285 million gallons
of oil are spilled each year into ocean, mostly from transport tankers. Oil pollution causes
damage to marine fauna and flora including algae, fish, birds, and invertebrates. About
50,000 to 2,50,000 birds are killed every year by oil. The oil is soaked in feathers, displacing
the air and thus interferes with buoyancy and maintenance of body temperature.
Hydrocarbons and benzpyrene accumulate in food chain and consumption of fish by man
may cause cancer. Detergents used to clean up the spill are also harmful to marine life.
Thermal Pollution
The increase in water temperature by industrial units such as steel and iron factories,
electric powerhouses and atomic power plants may be called as thermal pollution. Some of
the industries generate their own power supply where water is used to cool the generators.
This hot water is released into the main stream, causing a warming trend of surface waters.
If the drainage is poorly flushed, a permanent increase in the temperature may result.
Many organisms are killed instantly by the hot water resulting into a high mortality.
It may bring other disturbance in the ecosystem. The eggs of fish may hatch early or fail
to hatch at all. It may change the diurnal and seasonal behaviour and metabolic responses
of organisms” It may lead to unplanned migration of aquatic animals. Macrophysics population
may also be changed. As temperature is an important limiting factor, serious changes may
be brought about even by a slight increase in temperature in a population. Heat stress
(5-1 one above the normal growing temperature of organism) induces expression of specific
gene families called heat shock genes, which lead to the synthesis of a new set of proteins
called heat shock proteins. Heat shock proteins have been found in every organism from
unicellular prokaryotes to multicultural organisms including Homo sapiens. Heat Shock
Proteins synthesis lead to acquired thermo tolerance, i.e. the ability of an organism to
withstand a normally lethal temperature. Thermo tolerant genotypes show adaptations at
various levels of organization besides showing qualitative and quantitative differences in
heat shock proteins as compared to the thermo sensitive genotypes.
Solid Waste Management
Environmental problems also include solid waste disposal. At all levels of development
human beings produce domestic wastes. These comprises of kitchen wastes, ashes from
fires, broken utensils and worn-out clothing. The industrial revolution leads to the
concentration of people in urban areas with very high population density. This resulted in
addition of new sources of wastes from shops, institutions and factories. In developed countries
services for the regular removal of domestic and trade wastes have been in operation for last
many years.
Many changes have taken place in our society. The character of the wastes has altered
with rising living standards, changes in retail distribution methods and fuel technology.
Grave environmental concerns have come up with rise in construction of new buildings,
supermarkets, and industrial wastes of many kinds. In the industrialized countries, therefore,
basic health and environmental problems have been solved in the storage and collection of
solid wastes, although major problems remain in regard to resource recovery and disposal.
The technology of wastes handling is now highly developed. The substantial sectors of
industry are engaged in the production of equipment with regard to removal of wastes.
Many institutions give technical training and support. However developing nations like
India are facing the problems of urbanization with high population densities. The developing
countries are aware of the importance of avoiding the environmental pollution. The quality
of urban environment is a matter of growing concern and the importance of solid wastes
management is increasingly being recognized
Sources and Characteristics
Solid wastes generally refer to describe non-liquid waste materials arising from domestic,
trade, commercial, industrial, agriculture and mining activities and from the public services.
Disposal of sludge’s (liquid waste) of some kind fall within the scope of solid waste
management. These arise primarily from industrial sources and from sewage treatment
plants. Solid wastes comprise countless different materials; dust, food wastes, packaging in
the form of paper, metals, plastics or glass, discarded clothing and furnishing, garden wastes
and hazardous and radioactive wastes. The method and capacity of storage, the correct type
of collection vehicle, the optimum size of crew and the frequency of collection depend mainly
on volume and density. Just as solid wastes comprise a vast number of materials, they arise
from a multitude of separate sources as well as many kilometers of streets upon which solid
wastes accumulate. Thus, the four main aspects of solid wastes management are: (i) storage
at or near the point of generation, (ii) collection, (iii) street cleansing, (iv) disposal.
The main constituents of solid wastes are similar throughout the world, but the
proportions vary widely. As personal income rises, paper increases, kitchen wastes decline,
metals and glass increase, total weight generated rises and the density of the wastes declines.
Clearly, the amount of work involved in refuse collection depends upon the weight and
volume of wastes generated and the number of collection points from which the wastes have
to be removed.
Health and environmental implications
Improper handling of solid wastes results in increased potential risks to health and to
the environment both. Direct health risks concern mainly the workers in this field, who
need to be protected, as far as possible, from skin contact with wastes. For the general
public, the main risks to health are indirect and arise from the breeding of disease vectors,
primarily flies and rats. More serious, however, and often unrecognized, is the transfer of
pollution to water, which occurs when the leach ate from a refuse dump enters surface water
or wastes, either in the open air, or in plants that lack effective treatment facilities for the
gaseous effluents. Traffic accidents can result from wastes accumulated and dispersed on to
streets and roads. They have caused death and injury to people in the surrounding areas.
There also persists the specific danger of the concentration of heavy metals in the food
chain. These metals can be taken up by the plants growing on land on which sludge has
been deposited, creating risks to the animals which graze and the humans who consume
these animals.
Economic implications
Labour and transport absorb the major part of the operating cost of solid wastes
management services. The level of mechanization that should be adopted for solid wastes
management systems relates directly to the cost of labour, as compared to that of plant and
energy. There is not much variation, worldwide, in energy or mechanical plant costs, but
there is wide variation in the range of labour costs. Thus, there are no universally applicable
solid wastes management systems. Every country must evolve indigenous technology based
on the quantity and character of the wastes, the level of national wealth, wage rates,
equipment, manufacturing capacity, energy costs etc. It is necessary to deploy a complete
set of technical skills, which derive from several professional disciplines. These include civil
and mechanical engineering, chemical engineering, transport organization, land use planning
and economics.
Refuse Collection
A refuse collection service requires vehicles and labour. For their efficient development,
three components are basic:
(1) Travel to and from the work area,
(2) The collection process, and
(3) The delivery process.
The use of large, widely spaced communal storage sites is usually a failure because the
demand placed on the householder goes beyond his willingness to cooperate. Communal
storage points should, therefore, be at frequent intervals, Madras and Bangalore provide
fixed concrete containers. They are fairly successful because they place reasonable and
acceptable duty on the residents, thus very little domestic waste is thrown in the street.
In another system of block collection, a collection vehicle travels a regular route at
prescribed intervals, usually every two days or every three days, and it stops at every street
intersection, where a bell is rung. At this signal the residents of all the streets leading from
that intersection bring their wastes containers to the vehicle and hand them to the crew to
be emptied. A crew of one or two men is adequate in number, as they do not need to leave
the vehicle.
Sanitary Landfill Disposal
Land disposal (burying of wastes) is the only approved method of disposal, which is
performed at a single site. Incineration, composting, and salvage are either a form of refuse
handling or processing. They are not complete methods of disposal, and they require disposal
of residue. Sanitary landfill can be defined as the use of solid wastes for land-reclamation,
a typical example being the restoration, by filling to the original level of man made surface
dereliction such as a disused surface, mineral excavation. Solid wastes may also be used to
improve natural features by raising the level of low-lying land to enable it to be used or
cultivation or industrial development. Thus, sanitary land filling has two essential features,
which differentiate it from crude dumping:
(i) Only sites that will be improved not degraded, by a change of level are selected.
(ii) Simple engineering techniques are used to control the manner in which the wastes
are deposited, so that dangers to public health and the environment are avoided.
Unfortunately most of the world’s wastes are disposed off by uncontrolled dumping
which blights the land for any future use and causes serious risks of water pollution and
vector breeding. Very few cities operate sanitary land filling to standards, which totally
control health and environmental dangers; most of those that do are in the industrialized
countries.
Control of Hazards
(i) Control over pathogens is dependent upon a rigorous policy of covering the wastes
soon after deposit. This serves both to isolate the wastes and to retain the heat,
which is quickly generated during aerobic decomposition.
(ii) The main source of insects will be the eggs of flies. Which have been deposited in
the wastes before they arrive at the site. Most of these will be buried deep in the
wastes and will succumb to the temperature increase.
(iii) Fire at a sanitary landfill can arise from innumerable causes, hot ashes in a vehicle
delivering wastes: a cigarette thrown by a worker; the sun’s ray though a fragment
of glass on the surface. With some kinds of wastes the consequence of fire may be
very serious and underground fires have been known that ultimately caused the
collapse of the surface into voids caused by the fire.
(iv) The pollution of static water, ditches, river or the sea occurs when a sanitary
landfill adjoins a body of water. The normal source of the leach ate causing this
pollution is rain falling on the surface.
Incineration
Open burning, barrel burning, and other related uncontrolled forms of burning have a
long history of use. Many liquid wastes and pathological wastes are best disposed of by
incineration. Originally, solid waste incineration was practiced to reduce the quantity of
refuse or disposal. After it was proven that heat could destroy most pathogens, incinerators
were used in hospitals for destruction of pathological wastes. With few exceptions, incinerators
are not “good neighbors,” and the environmental nuisances of dust. Noise and air pollution
have provoked communities to an anti-incinerator philosophy. To overcome this negative
community feeling is going to require that incineration prove its worth and that imagination
be used in the design of future units. Incineration of solid wastes yields the highest percent
of volume reduction except for Pyrolysis. Unlike a sanitary landfill, incineration of solid
wastes can be performed on the premises of apartments, supermarkets, departments’ stores,
and similar establishments.
Composting
Composting involves the biological stabilization of solid matter either under aerobic or
anaerobic conditions. The end product of composing is an organic material, which could have
beneficial value as a soil conditioner or plant mulch. In addition to producing a modified
solid waste material, which can be useful in land reclamation, composting does yield a
volume reduction of solid waste by about 40-60% of the compost able fraction pyrolysis
Pyrolysis is a thermal process where oxidation of the organic fraction is not allowed to
occur. Instead, the organic matter is evolved from the refuse with heat, leaving an ash
consisting mostly of carbon and any inorganic matter, e.g. metal and glass are not removed
before Pyrolysis. Some of the gases, which have been volatized, are condensed while the
remainder is burned to supply the heat (energy) needed to pyrolyze the material. Since
oxidation is prevented, the Pyrolysis process must be performed in an atmosphere of argon,
helium or nitrogen.
Role of an Individual in Prevention of Pollution
Which are the most viable, efficient and economical ways to eliminate pollution problems?
We very often see people blaming public and government sectors to control pollution through
controlling market mechanisms and government blaming people to avoid and check pollution.
Who would control whom? Many ecologists and environmental scientists believe in that
pollution problems can be overcome by using market mechanisms to reduce pollution rather
than rigid rules and regulations. However, on the other hand man should identify and gear
up his own potential to curb down pollution. Man could achieve this by identifying his own
role at individual level in prevention of pollution. This is possible through environmental
awareness, education and enlightenment.
Ways and means by which pollution problems can be greatly reduced at individual level
are:
1. Masses at personal level should determine to consume optimum level of resources,
which would lead a comfortable life. Because excessive resource consumption is in
someway related to pollution problems and hazards (natural and anthropogenic
both).
2. Waste disposal at personal level should be optimally reduced as waste destruction
by any means causes pollution.
3. Maintenance of vehicles should remain proper as to avoid introduction of harmful
gases and other pollutants in to the atmosphere.
4. Generators and other household gadgets that add to pollution of environment should
be kept well maintained.
5. Use of chemical fertilizers should be limited as to avoid water pollution e.g. DDT
6. Timely disposal of waste to prevent decomposition of household refuge as to check
foul odours and spread of disease by insects, flies and other pathogenic bacteria.
7. Industrialists should check for proper disposal of treated water from factory units
as to avoid thermal pollution of water bodies. They should also deploy a water
treatment plant to prevent the flow of hazardous material.
8. Service centres of vehicles should minimize the disposal of organic solvents into the
main drains.
9. Music lovers should listen and operate their music systems at optimum levels as
to avoid noise pollution

<<< Previous                                                             Next >>>

YamEen Uncategorized

5 Pollution and its Factors part 2

Sources of Water Pollution
(i) Domestic sewage
This includes household’s wastes like food wastes, synthetic detergents used for washing
clothes and cleaning bathrooms and latrines and water based paints.
(ii) Industrial effluents
The industrial wastes are discharged in the adjoining rivers and streams through flush
lines of factories. The textiles, sugar and fertilizers factories, oil refineries, drugs manufacture,
rubber, and rayon fibers, the paper industries and the chemical factories all produce Chemical
pollution.
(iii) Agricultural source
Increased use of fertilizers has become essential for high yielding crop plants. Excess
of nitrates used as fertilizers seep into ground water is carried into lakes and pond. On
entering the drinking water supply system these create several health problems.
(iv) Pesticides
These include insecticides, fungicides, nematicides, rodenticides, herbicides and soil
fumigants. These contain chlorinated hydrocarbons, organophosphates, metallic salts,
carbonates, acetic acid derivatives etc. many pesticides are non-degradable. They pass through
the food chains and accumulate in fatty tissues thus causing several health hazards.
(v) Thermal pollution
Power plants and nuclear power stations are the main sources of thermal pollution of
water where water is used for cooling and becomes hot. The hot water on entering the main
water body raises its temperature, which kills fishes and other aquatic animals and increases
the rate of respiration in aquatic plants.
(vi) Pathogenic organisms
Sewage and domestic waste from houses introduces pathogenic organisms viz., protozoa,
worms-eggs and bacteria into water. This contaminated water if consumed causes jaundice,
typhoid, dysentery, cholera, tuberculosis etc.
(vii) Mineral oils
Oil from oil spills and washings of automobiles finds way into river water through
sewers.
(viii) Underground water pollution
Underground water particularly in cities and industrial areas is no more pure and safe.
The sources of underground water pollution are sewage, seepage, pits, industrial effluents,
septic tanks, fertilizers and pesticides, garbage etc.
(ix) Marine water pollution
River and stream network sources of water ultimately end up ocean and seas. Thus,
these acts as the sink of all natural and man-made water based pollutants. The main
sources of oceanic pollution are discharges of oil, greases, petroleum products, detergents,
sewage and garbage including radioactive wastes.
Effect of Water Pollutants
The main effects of water pollutants are:
1. Compounds of mercury, arsenic and lead are poisonous and chemically harmful as
they even affect water treatment plants e.g. organic sulphur compounds interfere
with nitrification.
2. Mercury when dissolved in water is absorbed by aquatic plants and enters the food
chain. Lead impairs metabolism and brings about congenital deformities, anaemia
etc.
3. Cadmium damages kidneys and liver.
4. Inorganic nitrates and phosphates promote growth of oxygen-consuming algae,
which result in the death of fishes and other aquatic animals.
5. Presence of dyes and compounds in the discharged water changes the colour of
water.
6. Soap, detergents and, alkalis result in foam formation.
7. Industrial effluents containing iron, free chlorine, phenol, manganese, oils,
hydrocarbons, ammonia, algae and microorganisms impair the taste and odours of
water.
8. The nitrates and phosphates dissolved in water accelerate the growth of
microorganisms, which consume much of the dissolved oxygen depriving fish and
other aquatic life (Eutrophication).
9. Biomagnifications is the increase of toxic materials at each tropic level of a food
chain.
For example, DDT after reaching a water system is absorbed by the microorganisms on
which smaller fishes feed. From them, DDT reaches the carnivorous animals. Since bigger
fishes consume more food, large amounts of DDT accumulates in their body.
CONTROL OF WATER POLLUTION
(i) Separate ponds and tanks to be used for cattle and animals.
(ii) Use of pesticides, insecticides and fertilizers should be done judiciously. Rapid
biodegradable substitutes for pesticides should be employed.
(iii) In towns where sewage facilities are not available, septic tanks should be made in
the houses.
(iv) Rivers and lakes should not be used for bathing or washing as it contaminates
water. .
(v) Domestic sewage and industrial wastes should be treated before discharging them
into drains.
Treatment of waste Water
Domestic sewage and industrial wastes should be properly treated before these are
drained in the mainstream water. Treatment involves the following two steps:
(i) Sewage treatment
It involves following steps:
Primary treatment. It involves physical processing of sedimentation, flotation and
filtration where sewage water is passed through screens to remove larger particles and then
through grinding mechanism to reduce the larger particles to smaller size. The sewage is
finally passed through settling tanks to remove suspended impurities.
Secondary treatment. Sewage obtained after primary treatment is sent to aeration tank
where it is mixed with air and sludge laden with bacteria and algae. The algae provide
oxygen to the bacteria and decompose organic matter into simple compounds. Chlorination
is finally done to remove bacteria.
Tertiary treatment. In the third and last step water is passed through ion exchangers
to remove dissolved salts.
(ii) Treatment of industrial effluents
Treatment of industrial effluents involves neutralization of acids and bases, removal of
toxic compounds, coagulation of colloidal impurities, precipitation of metallic compounds
and reducing the temperature of effluents to decrease thermal pollution.
SOIL POLLUTION
Soil Pollution
Like water and air, soil is also equally important for living organisms. It supports
plants on which. all other living organisms depend. The process of soil formation is so slow
that the soil may be regarded as a non-renewable source. Therefore, the study and control
of soil pollution is important. Any substance that reduces soil productivity is called soil
pollutant.
Sources of Soil Pollution
There are several materials, which adversely affect physical, chemical and biological
properties of the soil and thus reduce its productivity. These are
1. Chemicals present in industrial waste.
2. Pesticides and insecticides that are sprayed on crops. .
3. Fertilizers and manures that are added to the soil to increase the crop yield.
Effect of Soil Pollutants
Chemicals and pesticides affect the structure and fertility of soil by killing the soil
microorganisms. Pesticides are absorbed by the plants and then transferred to other organism.
Hence, they affected food chains and food webs. Excretory products of livestock and human
beings used as manure pollute the soil besides giving high yield. The faulty sanitation and
unhygienic practices of the people add to the soil pollution. Pathogens present in the wastes
and excreta contaminate the soil and vegetable crops causing diseases in man and
domesticated animals.
Types of Soil Pollution
It is of the following types-
(i) Positive soil pollution
Reduction in the productivity of soil due to the addition of undesirable substances like
pesticides, herbicides, fertilisers, etc. is called positive pollution. These pollutants have
cumulative effect and kill the soil organisms.
(ii) Negative soil pollution
It is caused by the removal 01 useful components from soil by erosion, deforestation and
improper methods of agriculture.
Salination of Soil
Increase in the concentration of soluble salts is called salination. This adversely affects
the quality and productivity of soil. It takes place in two ways: accumulation of salts dissolved
in irrigation water on the soil surface due to intensive farming and poor drainage, and
deposition of salts as white crust during summer months drawn by capillary action from the
lower surface to the top surface.
Control of Soil Pollution
Various measure to control soil pollution are-
1. Transfer stations for bulk shifting of refuse should be constructed in cities and big
towns.
2. Pneumatic pipes should be laid for collecting and disposing wastes.
3. Materials like paper, glass and plastics can be recycled.
4. Metals should be recovered from scrap and disposed materials.
5. Use of chemical fertilizers should be reduced by the use of bio fertilizers and
manures.
6. Use of pesticides can be reduced by adopting biological control of pests.
7. Use of cattle dung and agricultural wastes in biogas plants should be encouraged.
8. Deforestation can check soil erosion to a great extent.
Land Degradation
Besides pollution, land and soil face several other problems. Removal of topsoil is called
soil erosion. Soil erosion factors are water, wind, ocean, waves and glaciers, felling of trees,
overgrazing by cattle, over-cropping etc. Erosion occurs both in wet and dry regions. It leads
to floods.
Soil Erosion in India
Soil erosion is a worldwide phenomenon, but it is especially high in Central Africa,
China, India, Nepal, Australia, Spain, USA and USSR. India loses about 40,000 hectares of
land every year as an effect of wind and water erosion. Damage to the topsoil is 18.5% of
the total world’s loss. This is due to overgrazing by livestock. The population of livestock in
India is the highest in the world. Overgrazing damages the topsoil, which reduces soil
fertility.
(i) Deforestation of overgrazing
Over-grazing is the main cause of soil erosion in India. Roots of grasses act as binding
material and keep the soil intact, which upon grazing are destroyed.
(ii) Desertification
Loss of soil productivity by erosion of top soil results in the formation of deserts.
Deserts are spreading in all continents. Desertification takes place by shifting of sand dunes
by wind and .over-grazing. That desert in India is spreading at the rate of 12,000 hectares
of land every year.
(iii) Shifting cultivation
Tribal communities follow the practice of cutting down trees and setting them on fire
and then raising the crops on the resulting ash. This is called Jhuming in northeastern
India. It is harmful if the Jhuming cycles are longer than ten years but short cycles destroy
forests and cause soil erosion. e.g. Asia and Africa. .
(iv) Developmental activities
Large areas of fertile and productive croplands, woodlands and grasslands are lost to
various developmental activities such as rapid urbanization, building of airports, industries,
railways, roads, mining and construction of dams.
Control of Land Degradation
Following ways can control Land degradation
1. Restoration of forests and grass cover can help in prevention of soil erosion and
floods.
2. By replacing shifting cultivation with crop rotation, mixed cropping or plantation
cropping. Providing adequate drainage to irrigated and flood-prone lands can prevent
salinity.
3. Desertification can be controlled by spread of appropriate plant species and by
raising trees as wind breaks.
Noise Pollution
Noise can be defined as unwanted/unpleasant sound. So noise pollution is unwanted
sound dumped into the atmosphere without regard to the adverse effects it may have. In
our country urbanization and industrialization have become twin problems. Cities and towns
have sprouted up where industries are concentrated. Lack of town’ planning had led to
residential, commercial and industrial areas being mixed up. Houses, schools and hospitals
are situated near industries. All the boons of industrialization and civilization such as
motors, horns, heavy and light machinery, work and movement, blaring radios, supersonic
aeroplanes have become disturbing and irritant. Our ears can hear ordinary conversation
between 30-60 decibels. Modern conversation has a noise value of 60 decibels. A decibel
value greater than 80 decibels causes noise pollution. Noise becomes troublesome above 140
decibels..

<<< Previous                                                             Next >>>
YamEen Uncategorized

5 Pollution and its Factors part 1

INTRODUCTION
Pollution may be defined as an undesirable change in the physical, chemical or biological
characteristics of air, water and land that may be harmful to human life and other animals,
living conditions, industrial processes and cultural assets. Pollution can be natural or manmade. The agents that pollute are called pollutants.
Pollutants
Pollutants are by-products of man’s action. The important pollutants are summarised
below:
• Deposited matter—Soot, smoke, tar or dust and domestic wastes.
• Gases—CO, nitrogen oxides, sulphur oxides, halogens (chlorine, bromine and iodine).
• Metals—Lead, zinc, iron and chromium.
• Industrial pollutants—Benzene, ether, acetic acid etc., and cyanide compounds.
• Agriculture pollutants—Pesticides, herbicides, fungicides and fertilizers.
• Photochemical pollutants—Ozone, oxides of nitrogen, aldehydes, ethylene,
photochemical smog and proxy acetyl nitrate.
• Radiation pollutants—Radioactive substances and radioactive fall-outs of the
nuclear test.
Classification of Pollutants
On the basis of natural disposal, pollutants are of two types:
(i) Non-degradable pollutants
These are the pollutants, which degrade at a very slow pace by the natural biological
processes. These are inorganic compounds such as salts (chlorides), metallic oxides waste
producing materials and materials like, aluminium cans, mercuric salts and even DDT.
These continue to accumulate in the environment.
(ii) Biodegradable pollutants
These include domestic sewage that easily decomposes under natural processes and can
be rapidly decomposed by natural/ artificial methods. These cause serious problems when
accumulated in large amounts as the pace of deposition exceeds the pace of decomposition
of disposal.
On the basis of the form in which they persist after their release into the environment,
pollutants can be categorized under two types:
(i) Primary pollutants : These include those substances, which are emitted directly
from some identifiable sources. This include-
(a) Sulphur compounds: SO2, SO3, H2S produced by the oxidation of fuel.
(b) Carbon compounds: Oxides of carbon (CO+CO2) and hydrocarbons.
(c) Nitrogen compounds: NO2 and NH3.
(d) Halogen compounds: Hydrogen fluoride (HF) and hydrochloric acid (HCl).
(e) Particles of different size and substances: These are found suspended in air.
The fine particles below the diameter of 100u are more abundant and include
particles of metals, carbon, tar, pollen, fungi, bacteria, silicates and others.
(ii) Secondary pollutants. The secondary pollutants are produced by the combination
of primary emitted pollutants. in the atmosphere. In bright sunlight, a photochemical
reaction occurs between nitrogen oxides; oxygen and waste hydrocarbons from
gasoline that forms peroxyacetyle nitrate (PAN) and ozone (O3), Both of them are
toxic components of smog and cause smarting eyes and lung damage.
(iii) Smog. The fog deposited with smoke and chemical fumes forms a dark and thick
covering, the smog. Smog is very common in almost all the industrial areas as the
smog is trapped for many days by the stagnant air. It is harmful both for animals
and plants.
AIR POLLUTION
The WHO defines air pollution as the presence of materials in the air in such
concentration which are harmful to man and his environment. A number of ingredients find
their way in the air and these are mostly gases, which rapidly spread over wide areas.
SOURCES OF AIR POLLUTION
Various sources of air pollution are fossil fuels, industries, agricultural activities, wars,
natural causes arid emissions from vehicles.
(i) Burning Fossil Fuels
Burning of wood, charcoal and other fossil fuels causes air pollution by the release of
carbon dioxide (CO2), carbon sulphur dioxide etc. Petroleum consists mainly of hydrocarbons,
sulphur and nitrogen.
(ii) Emissions from Automobiles
Vehicles are mainly responsible for more than 80% of total air pollution. 

The major pollutants released from automobiles, locomotives, aircraft etc., include CO, unburnt
hydrocarbons and nitrogen oxide.
(iii) Industries
Paper and pulpfactories, petroleum refineries, fertilizer plants, and steel industries,
thermal power plants are the main sources of air pollution. They add various harmful gases
like CO, SO3, NO, Hydrocarbons etc., to the atmosphere. Textile factories release cotton dust
into the air. Cities experiencing this type of pollution are Kanpur, Surat and Ahmedabad.
The pesticide and insecticide industries are posing serious threat to the environment. Food
processing industries and tanneries emit offensive odors. Release of poisonous gases from
accidents also poses serious threats. e.g. Bhopal Gas Tragedy in which methyl isocynate
(MIC) gas leakage killed several people. In Tokyo, about 34 tones of carbon particles mixed
with other suspended particles settle per square kilometer every day.
(iv) Agricultural Activities
Spraying of insecticides and weedicides also cause air pollution. These, when inhaled
create severe problems to both animals and man.
(v) Wars
Various forms of explosives used in war pollute the air by releasing poisonous gases.
This greatly disturbs the ecology of the area. Nuclear explosions pollute air by radioactive
rays. The effects of nuclear explosions on Hiroshima and Nagasaki are well-known examples.
(vi) Natural Causes
Gas emissions from active volcanoes, marsh gas, spores of fungi and pollens are the
natural causes of air pollution.
COMMON AIR POLLUTANTS
Air pollutants are of two main types ~gaseous and particulate. Oxides of carbon. Nitrogen
and sulphur are gaseous pollutants. Particulate pollutants may be solid or liquid particles,
larger particles settle down quickly viz., sand and water droplets whereas small dust particles
remain suspended in air for a long time. These are added into the atmosphere by the
processes of blasting, drilling, crushing, grinding and mixing.
(i) Carbon Dioxide
CO
2 content of air has increased by 20% during the last century. CO2 causes nausea
and headache. It’s increase in the air may cause green house effect, rise in the atmospheric
temperature. This may melt the polar ice resulting in rise in level of oceans and flooding
of coastal regions.
(ii) Carbon Monoxide
It is a very poisonous gas and is produced by incomplete combustion of fuel. If inhaled.
it combines with hemoglobin and reduces its oxygen-carrying capacity. This leads to laziness,
reduced vision and death.


(iii) Oxides of Nitrogen
These include NO and NO
2, which are released by automobiles and chemical industries
as waste gases and also by burning of materials. These are harmful and lower the oxygen
carrying capacity of blood.
(iv) Oxides of Sulphur
SO
2 and SO3 are produced by burning of coal and petroleum and are harmful to buildings,
clothing, plants and animals. High concentration of SO2 causes chlorosis (yellowing of leaves),
plasmolysis, damage to mucous membrane and metabolic inhibition. SO2 and SO3 react with
water to form Sulphuric and sulphurous acids. These may precipitate as rain or snow
producing acid rain or acid precipitation.
(v) Photochemical Oxidants
Formed by the photochemical reactions between primary pollutants, viz. oxides of
nitrogen and hydrocarbons. Nitrogen oxides in the presence of sunlight react with unburnt
hydrocarbons to form peroxyacyl nitrate (PAN), Ozone, aldehydes and some other complex
organic compounds in the air.
(vi) Hydrocarbons
These are unburnt discharges from incomplete combustion of fuel in automobiles. These
form PAN with nitrogen oxides, which is highly toxic.
(vii) Particulate Matter
Industries and automobiles release fine solid and liquid particles into the air. Fly ash
and soot from burning of coal, metal dust containing lead, chromium, nickel, cadmium, zinc
and mercury from metallurgical processes; cotton dust from textile mills; and pesticides
sprayed on crops are examples of particulate pollutants in the air. These are injurious to
respiratory tract.
(viii) Aerosols
Aerosols are chemicals released in the air in vapour form. These include fluorocarbon
(carbon compound having fluorine) present in emissions from the Jet aeroplanes. Aerosols
deplete the ozone layer. Thinning of ozone layer results in more harmful ultraviolet rays
reaching the earth, which are harmful to skin, and can lead to skin cancer also.
(ix) Radioactive Substances
These are released by nuclear explosions and explosives. These are extremely harmful
for health.
(x) Fluorides
Rocks, soils and. minerals containing fluorides release an extremely toxic gas called
hydrogen fluoride on heating. This gas is highly injurious to livestock and cattle.
POLLUTION IN INDIA
India supports a large network of factories and industries. These factories are generally
localized in eight or ten large industrial centres. These are also a great source of air as well
water pollution. To be on a safer side delocalisation of industries is the need of the time.
This would lead to an even distribution of pollutants and faster degeneration of pollutants.
The major pollutants coming out from these industries are –
(i) Industrial Pollutants. The common air pollutants from industries are SO2, CO,
CO
2, H2S and hydrocarbons together with dust, smoke and grit. These are produced
by the burning of coal and petroleum and by the combustion of lignite at thermal
power stations. The chemical industries release HCl, chlorine, nitrogen oxide and
oxides of copper, zinc, lead and arsenic.
The fertilizer factories at Gorakhpur and Ahmedabad; the steel industries at Bhilai,
Rourkela, Jamshedpur and Durgapur pollute the air with above-said gases.
(ii) Automobile Exhausts. Automobiles run by petrol and diesel produce CO, nitrogen
oxides and hydrocarbons. Hundreds and thousands tons of hydrocarbons and CO
are emitted into air daily. Metropolitan cities harbour lakhs and crores of
automobiles. Every gallon of petrol consumed by automobiles produces 3 pounds of
carbon monoxide and 15 pounds. of nitrogen oxide.
(iii) Ionizing Radiations from Radioactive Substances. Ionizing radiations include alpha,
beta particles and the gamma rays etc. These are produced by atomic explosions
and testing of atomic weapons.
Effects of Air Pollution
Effect on Plants
(i) SO2 causes chlorosis and also results in the death of cells and tissues.
(ii) Fluorides and PAN damage leafy vegetables such as lettuce and spinach.
(iii) Oxides of nitrogen and fluorides reduce crop yield.
(iv) Smog bleaches and blaze foliage of important leafy plants.
(v) Hydrocarbons cause premature yellowing, fall of leave and flower buds, discoloration
and curling of sepals and petals.
(vi) Smoke and dust cover the leaf surface and reduce photosynthetic capacity of plants.
(vii) Ozone damages cereals, fruits, and cotton crop.
Effect on Man
The effect of pollutants on animals and man are as follows-
(i) Ozone causes dryness of mucous membranes, changes eye vision, causes headache,
pulmonary congestion and oedema.
(ii) Ozone has been reported to produce chromosomal aberrations.
(iii) SO2 causes drying of mouth, scratchy throat, smarting eyes and disorders of
respiratory tract.
(iv) SO3, CO and NO2 diffuse into blood stream and reduce oxygen transport. CO
damages cardiovascular system. Hydrocarbons and other pollutants act, as
carcinogens and lead to different cancers.
(v) Cotton dust leads to respiratory disorders e.g. bronchitis and asthma.
(vi) Smoking of tobacco causes cancerous growth in lungs.

Change in Climate
CO
2 content of air is increasing due to deforestation and combustion of fuel. This
increase is affecting the composition and balance of gases in the atmosphere. Increase in
CO
2 concentration may increase the atmospheric temperature, producing green house effect
A rise of global temperature by more than 2-3 degrees may melt glaciers and polar ice. This
would lead to a rise in ocean level and consequent flooding and submergence of coastal
areas. Rainfall pattern may also change, affecting agricultural output in various regions of’
the world. Aerosols deplete the ozone layer in the stratosphere. Thinning of ozone layer
would permit more of the harmful ultraviolet rays to reach the earth. This may cause,
sunburn, blindness and inactivation of proteins, RNA, DNA and plant pigments.
Aesthetic Loss
Dust and smoke spoils the beauty of nature. Especially the mountain environments,
which serve as a great attraction for tourists. Foul odours emitted by industries, automobiles,
dirty drains and garbage heaps in cities are a great nuisance.
Control of Air Pollution
Following measures have been suggested to control air pollution-
(i) Some gases, which are more soluble in a particular liquid than air, for example,
ammonia in water, can be separated by dissolving in it
(ii) Particles larger than 50 mm are separated in gravity settling tanks. Using cyclone
collectors or electrostatic precipitators separates fine particles.
(iii) The height of chimneys should .be increased to the highest possible level to reduce
pollution at the ground level.
(iv) SO2 pollution can be controlled by extracting sulphur from the fuel before use.
(v) Pollution control laws should be enforced strictly.
(vi) Trees should be planted on the roadside, riverbanks, parks and’ open places as they
keep the environment fresh.
(vii) Population growth, which is the main cause of pollution should be checked.
(viii) Nuclear explosions should be restricted.
Water Pollution
Water is extremely essential for life, this common fact is known to all. It is required to
meet our basic needs in day to day life viz., cooking, drinking, bathing, disposal of sewage,
irrigation, generating electricity in power plants, cooling and manufacturing different products
in industries and the disposal of industrial wastes. During all these processes the undesirable
substances are added to the water resources to a great extent. This alters the basic chemistry
of water in rivers and streams.

<<< Previous                                                             Next >>>
YamEen Uncategorized

4 Biodiversity and Conservation part 2

1. Endemic Species of India
India has a very rich element of endemics in its flora. According to Chatterjee (1940)
Indian subcontinent has about 61.5 percent to endemic flora with about 7,000 endemic speciesand 134 endemic genera. Of these the Himalayas and the Khasi Hills account for about 3,000
and Deccan peninsula for about 2,000 endemic species. These figures speak eloquently of the
great need for protecting the endemics. This can be done effectively by carefully analyzing the
floristic composition of the various phytogeographical units of Indian flora and by selecting
suitable natural forests in these units and preserving them as ‘Biosphere Reserves’.
Sapria himalayana, Uvaria Inroad, Alcimandra cathcartii Magnolia gustavii, M pealiana,
Pachylarnax pleiocarpa, Nepenthes khasiana, Dicentra royler several species of Primula and
Rhododendron and the Lady’s Slipperorchids. P. aphiopodilum insigne, P. hirsutissimum, P.
faireenum, P. spicerianum and P. venusturm, are some of the noteworthy endemics of the
Himalayas and Khasi Hills. Antiaris taxicaria, Campanual cytinoides, Pedicularis perroter
and the some species of the Podostemaceae are endemic to Western ghats/the Nilgiri Hills
in South India.
2. Endangered Flora and Fauna of India
Some plants and animals have already become extinct and there are many facing
danger of extinction. The basic reasons of extinction of wildlife are as follows:
(1) Destruction of their natural habitats due to expanding agriculture, urbanization
and industrialization.
(2) Overgrazing by domestic animals that convert the area into deserts.
(3) Poaching for meat, skin, fur, ivory, rhino horns etc.
(4) Export of some species.
The Botanical Survey of India (BSI) could so far complete survey of plant resources. in
only about 3/5th of the country. As per the targets set, BSI should have complete survey
of the remaining 2/5th of the country by 1998. It is planned to publish National Flora of the
country in 24 volumes by 2000 A.D.
The Zoological Survey of India (ZSI) could so far survey only about 1/3 of the country,
and is planned to complete the survey of the 75% of the remaining 2/3rd area of the country
by 2000 A.D. Sixty-two volumes of Fauna of India are to be brought out by 2000. Data
regarding all endangered plant and animal species of the country are also not complete. It
was set that data regarding all endangered plant species will be inventoried by 1992, for
which BSI had been restructured. In its Annual Report (1987-88); D.O. En. Has reported to
publish Vol. I of Red Data Book of Indian plants covering 235 species. Red Data Book of
Indian Plants Vol. II containing about 200 rare and endangered species is completed and
printed (D.O. En. Annual Report, I988-89). The status survey of Endangered animal species
is being done and is claimed to be completed and Red Data Book compiled by 1995.
According to the Red Data Book of IUCN (International Union for Conservation of
Nature and Natural Resources), more than 1000 creatures are threatened with extinction,
some very soon, some within a decade or so. Among these facing most immediate danger
are, all species of rhinoceros particularly the Indian variety the Royal Bengal, and Siberian
Tigers, the Mexican grizzly bear, the red wolf, the mountain gorilla; the Arabian oryx and
the Asiatic lion.Indian Endangered Flora
In India, nearly 450-plant species have been identified as endangered, threatened or
rare. A list of some such species in different parts of the country is given below (this may
not be a complete list).
Table 4.6. List of Some Endangered, Threatened or Rare Species
S.No. Species Family
Himalayas and Eastern India
1. Abies delavayi Pinaceae
2 Acanthephippium sylhetense Orchidaceae
3. Aconitum deinorrhzum Ranunculaceae
4. Adinandra griffithii Theaceae
5. Aglaia perviridis Meliaceae
6. Amblyanthus multiflorus Myrsinanceae
7. Anacolosa ilicoides Oleaceae
8. Anoectolchilus sikkimensis Orchidaceae
9. Angopteris eracta Angiopteridaceae
10. Aphyllorchis Montana Orchidaceae
11. Arachnanthe cathcartii Orchidaceae
12. A. clarkei Orchidaceae
13. Artemisia Asteraceae
14. Astragalus strobiliferus Papilionaceae
15. Camellia caduca Theaceae
16. Cyathea gigontean Cyatheaceae
17. C. elegans Orchidaceae
18. Dendrobium densiflorum Orchidaceae
19. Dioscorea deltoidea Dioscoreaceae
20. D. ruflesiana Asclepiadacea
21. Gentiana Kurroo Gentianaceae
22. Lespedeza elegans Papilionaceae
23. Nardostachys grandiflora Valerianaceae
24. Nepenthes khasiana Nepenthaceae
25. Osmynda regalis Osmundaceae
26. Picea brachytyla Pinaceae
27. Rauvolfia serpentina Apocynaceae
28. Rhododendron arizelum Ericaceae
29. Saussurea bracteata Asteraceae
30. S. lappa Asteraceae
31. Zanthoxylum scandens Rutaceae

Rajasthan and Gujarat
32. Commiphora wightii Burseraceae
33. Helichrysum cutchicum Asteraceae
34. Hyphaene dichotoma Arecaceae
35. Meconopsis betonicifolia Papaveraceae
Gangetic plain
36. Aldrovanda vesiculosa Droseraceae
Peninsular India
37. Anemia tomentosa Schizaeaceae
38. Ceropegia fantastica Asclepiadaceae
39. Cycas beddomei Cycadaceae
40. Lobelia nicotionaefolia Lobeliaceae
41. Piper barberi Piperaceae
42. Pterospermum obtusifolium Sterculiaceae
Andaman and Nicobar Islands
43. Depterocarpus kerrii Dipterocarpaceae
44. Hippocratea nicobarica Hippocrateaceae
45. Lagerstroemia hypoleuca Lythraceae
46. Myristica andamanica Myristicaceae
47. Podocarpus neriifolius Podocarpaceae
48. Uvaria nicobarica Annonaceae
Indian Endangered Fauna
Some of the animal species listed below has been identified as endangered ones. This
may not be a complete list. The chici’s species are:
Table 4.7 : List of Animals Species
Mammals Four-horned antelope Bengal florican
Lion-tailed macaque Indian bison Nicobar pigeon
Nilgirilangur Wild yask Wreathed hornbill
Indian wolf Gangetic dophin Reptiles
Red fox Baleen whales Turtle
Himalayan Brown bear Marinedolphines Tortoise
Red panda Birds Terrapin
Indian Lion Geese Green sea turtle
Leopard Black eagle Tortoise shell turtle
One-horned rhinoceros Bamboo partridge Esturine crocodile
Indian wild ass Mountain quail Marsh crocodile
Andaman wild pig Chir pheasant Monitor lizards
Kashmir stag Peacock pheasant Indian python
Swamp deer Indian peafowl Amphibia
Alpine musk deer Blacknecked crane Viviparous toad
Blackbuck Masked finfoot Indian salamander
Chinkara Houbra bustard
CONSERVATION OF BIODIVERSITY
The hope for conservation of natural biodiversity however rests on preservation of
selected ecosystems and representative areas of different vegetation types in the country. as
well as on saving some of the extinction-prone species. The number of endangered species
of plants and animals is on the rise, which has prompted government and non-governmental
organizations to take certain steps in this direction. Forestry and wildlife were primarily
under the control of state governments but later on looking to the gravity of the situation
a separate Ministry of Environment and Forests was established.
The aims and objectives of wildlife management in India includes the following
(i) Protection of natural habitats
(ii) Maintenance of a viable number of species
(iii) Establishment of biosphere reserves
(iv) Protection through legislation
Some of the non-government organizations working in this direction are
(i) Bombay Natural History Society
(ii) Wildlife Preservation Society of India, Dehradun.
(iii) World Wide Fund for Nature India (WWF)
Laws Governing Biodiversity Conservation in India
(i) The Madras Wild Elephant Preservation Act, 1873.
(ii) All India Elephant Preservation Act, 1879.
(iii) The Indian Fisheries Act, 1897.
(iv) Wild Birds and Wild Animals Protection Act, 1912.
(v) The Indian Forest Act, 1927.
(vi) Bengal Rhinoceros Act, 1932.
(vii) Haily National Park Act.. 1936.
(viii) Bombay Wild, Animals and Wild Birds Protection Act, 1951.
(ix) Assam Rhinoceros Protection Act, 1954.
(x) The Cruelty Against Animals Act, 1960.
(xi) The Wildlife (Protection) Act, 1972.
(xii) The Forest (Conservation) Act, 1980.
(xiii) Wildlife (Protection) Amendment Act; 1991.
Conservation of Forests and National Ecosystems Act, 1994.
IN-SITU AND EX-SITU CONSERVATION OF BIODIVERSITY
The goal of biodiversity conservation can be attained in a number of ways. The concept
of gene banks regulates all these methods.
In-situ conservation
It can be defined as the conservation of plants and animals in their native ecosystem
(natural habitats) or even man made ecosystem, where they naturally occur.
This type of conservation is applicable to wild flora and fauna as conservation is achieved
through protection of populations in their natural ecosystems. The concept of protected
areas falls under this category e.g. National Parks, Sanctuaries and Biosphere reserves
etc.
Ex-situ conservation
It can he defined as the conservation of plants and animals away from their natural
habitats, which includes collection of samples of genetic diversity and their treatment in the
laboratory, where they are cultured.
The concept of ‘gene banks’ has primarily become the talk for ex-situ conservation as
it is important for conservation of agricultural crops and forestry based afforestation
programmes. Genetic resource centres fall under this category and include botanical gardens,
zoos etc.
INSTITUTIONS FOR “EX-SITU” CONSERVATION OF BIODIVERSITY
(a) National Bureau of Plant Genetic Resources (NBPGR)
The set up was established in 1976 by the Indian Council of Agricultural Research
(ICAR) New Delhi for “Ex-Situ” conservation of plant genetic resources for agri-horticultural
and agri-silvicultural activities. Built- in long term cold storage (Gene Banks) have been
installed in New Delhi to conserve genetic resources at low temperature of 20°C. At present,
NBPGR holds about 48.5 thousand accessions of diverse species of economically important
plants (Khanna & Singh 1987). A number of scientific organizations dealing with storage of
genetic material of various crop plants have been established in India after independence.
They are “Rice Research Institute”, Cuttack, “Potato Research Institute”, Shimla & “Indian
Institute of Horticultural Research”, Bangalore.
(b) National Bureau of Animal Genetic Resources (NBAGR)
It was established in the 1980’s in Kamal, Punjab: for preservation of germless of
improved varieties of cattle’s-cows, buffaloes, goats, sheep, camels and oxen and their various
breeds found in different parts of India. Other organizations for “ex-situ” conservation of
animal germplasm are “National Bureau of Fish Genetic Resources”. Lucknow and Wildlife
Research Institute of India, Dehradun. At WRI a “gene bank” of all wild and domesticated
animals of India is coming up.
Protected areas of India for “In-Situ” Conservation of Biodiversity:
Three types of protected areas-
(i) Wildlife Sanctuaries;
(ii) National Park;
(iii) Biosphere Reserves were created in India for “In-Situ” conservation of biodiversity.
As on 31 March, 1994 there were 421 Wildlife Sanctuaries, 75 National Park, 14
Biosphere Reserved in India covering about 4% of total geographical area. In-situ conservation
of wildlife is a comprehensive system of protected areas. There are different categories of
protected areas, which are managed with different objectives for bringing benefits to the
society. The major protected areas include: (i) National Parks, (ii) Sanctuaries, (iii) Biosphere
Reserves etc. These areas vary considerably in size, design, purpose and effectiveness of
management.
Table 4.8. Distribution between National Park, Sanctuary and Biosphere Reserve
S.No. National Park Sanctuary Biosphere Reserve
1. Associated to the habitat These are species oriented Takes into consideration
of wild animal species as pitcher plant, Great the entire ecosystem.
like rhino, tiger, lion etc. Indian Bustard.
2. The size range is Size range is Size range over
0.04-3162 sq.km. 0.61-7818 sq. km. 5670 sq. km.
3. Boundaries marked by Boundaries not sacrosanct Boundaries marked by
legislation legislation
4. Disturbance only limited Limited disturbance Disturbance only limited
to buffer zone to buffer zone.
5. Tourism allowed Tourism allowed Tourism generally not allowed
6. Scientific management Scientific management Scientifically managed
is lacking is lacking
7. No attention is paid to No attention is paid to Attention is paid
gene pool conservation gene pool conservation
(i) National Park
According to the Indian Board for Wild Life (IBWL), “a National Park is an area
dedicated by statute for all time to conserve the scenery, natural and historical objects, to
conserve the wild life there in and to provide for enjoyment of the same in such manner and
by such means, that will leave them unimpaired for the enjoyment of future generations
with such modification as local conditions may demand”.
The history of National parks in India begins in 1936 when the Hailey (now Corbett)
national parks of United Provinces (now Uttar Pradesh) was created. The area is declared
for the protection and preservation for all time of wild animal life and wild vegetation for
the benefit and advantage and enjoyment of the general public. In this area hunting of
fauna or collection of flora is prohibited except under the direction of park authority.
Table 4.9. Wildlife Reserves in Different Status
State Wildlife Reserve
Andhra Pradesh Kawal, Pocharam, Neelapattu
Arunachal Pradesh Namidapha
Assam Kaziranga, Manas
Bihar Hazaribarh, Belta
Goa Mollen
Gujarat Gir, Wild Ass, Nal Sarovar
Haryana Sultanapur lake
Himachal Pradesh Gobin-sagar
Jammu & Kashmir Dachingam
Karanataka Bandipur, Nagarhole
Kerala Periyar, Neyyar
Madhya Pradesh Kanha
Maharashtra Pench, Nawegaon, Dhakna-Kolkaz
Manipur Keibul
Meghalaya Balapakrani
Mizoram Dampa
Nagaland Intangki
Orissa Simplipal, Chilka lake
Punjab Abohar
Rajasthan Ranthambore, Ghana
Sikkim Kanchenjunga
Tamil Nadu Guindy, Mundumalai, Annamalai
Uttar Pradesh Corbett, Dudwa
West Bengal Mahanandi, Jaldapara, Deer Parks, Sunderban
(ii) Sanctuary
The Indian Board for Wild Life has defined a sanctuary as, ‘An area where killing,
hunting, shooting or capturing of any species of bird or animal is prohibited except by or
under the control of highest authority in the department responsible for the management
of the sanctuary and whose boundaries and character should be sacrosanct as far as possible.
By June 1992 India had 416 sanctuaries. The Board has further clarified the position by
stating that while the management of sanctuaries does not involve suspension or restriction
of normal forest operation, it is desirable to aside a completely sacrosanct area within a
sanctuary to be known as ‘Abhyaranya’. It has also indicated that sanctuaries should be
made accessible to the public.

In India sanctuary is usually created by an order or gazette notification of State
government. So the weakness of a sanctuary is that it can be desanctuarized merely by
another order or gazette notification of a State government because it is not safeguarded by
any proper legislation. The idea behind a wild life sanctuary and a national park is same,
i.e., maximum protection, preservation and conservation of wild animals. But the fundamental
difference between the two is that a sanctuary is created by order of a competent authority,
who may be the chief conservator of forest: or minister of a State, while a national park can
be harmed, abolished or changed only by the legislation of a State. There are, title status
and degree of permanency and protection is much higher in a national park than in a
sanctuary. In a wild life sanctuary private ownership rights may continue and forestry
usages also may continue so long as wild life conservation is not adversely affected. However,
in a national park all private ownership rights are extinguished and all forestry and other
usages are prohibited. Every national park should have the minimum requisites of fauna,
flora and scenery etc. There should be sufficient means of management and protection in a
sanctuary to be upgraded as national park.
(iii) Biosphere Reserves
Biosphere Reserves have been described as undisturbed natural areas for scientific
study as well as areas in which conditions of disturbance are under control. These serve as
the centres for ecological research and habitat protection, The “Biosphere consists of two
main zones as:
Figure 4.1: Diagrammatic representation of a typical biosphere reserve.
UNESCO launched biosphere Reserve National Programme in 1971 under its Main and
Biosphere Programme (MAB). The main objectives of the programme are as follows:
• Conserve biological diversity
• Safeguard genetic diversity
• Provide areas for basic and applied research
• Opportunity for Environmental Science and training
• Promote international cooperation
• Promote management of biotic resources
In January 1989, 274 biosphere reserves had been established in 74 countries out of
which 14 proposed sites found place in India. These are as follows:
Table 4.10. Biosphere Reserves in India
S.No. Biosphere Reserve State
1. Nilgiris Tamil Nadu, Kerala and Karanataka
2. Namdapha Arunachal Pradesh
3. Nanda Devi, Uttarakhand Uttar Pradesh
4. (Valley of flowers) Uttar Pradesh
5. Andamans Andamans & Nicobar
6. Gulf of Mannar Tamil Nadu
7. Kaziranga Assam
8. Sunderbans West Bengal
9. Thar desert Rajasthan
10. Manas Assam
11. Kanha Madhya Padesh
12. Nokrek Meghalaya
13. Little Rann of Kutch Gujrat
14. Great Nicobar Island Andamans & Nicobar
The country falls under 2 realms and 12 biogeographical provinces as under:
Ladakh, Himalayas, Highlands, Malabar, Bengal, Indus-Ganga, Assam-Burma.
Coromondal Deccan, Thar Desert, Lakshdweep, Andaman, Nicobar Islands.
Position in India
India’s Department of Environment functions as the nodal agency for United National
Environment Programme (UNEP), the South Asia Cooperation Environment Programme
(SACEP) and the International Union for Conservation of Nature and Natural Resource
(IUCN). India has been actively participating in the various sessions of UNEP with a view
to ensure that programmes are more relevant to the developing countries.
The South Asia Cooperative Environment Programme has recently set up the intergovernmental organization with Afghanistan, Bangladesh, Bhutan, India, Maldives, Pakistan,
Sri Lanka and Iran as its members. At the 1981 ministerial level meeting, areas were
identified for implementation. India was assigned the focal point responsibilities in the
areas of Environment Education, Environmental Legislation and Wild Life Management. At
the 1983 Government Meeting of SACEP number of projects have been identified for
implementation in the area of Energy, Environmental Science, Legislation and Environmental
Impact Assessment. India has a number of on-going Bilateral Programmes with both developed
and developing countries.
The Constitutional directives (Art. 48 and 51-A) and development policy have provided
a strong base for enactment of legislative measures as required for environmental protection
There are several laws enacted from time to time, which are directly related to environmental
protection. Among them more recent ones are the Insecticides Act, 1968, Wildlife Protection
Act 1972, Water (Prevention and Control of Pollution) Act 1974, Water Pollution Act 1977,
Forest Conservation Act 1980 and the Air (Prevention and Control of Pollution) Act, 1981.
The Endangered Species Act
Passage of the U.S. Endangered Species Act of 1973 and the Committee on the Status
of Endangered Wildlife in Canada (COSEWIC) in 1976 represented a powerful new approach
to wildlife protection. Endangered species are those considered in imminent danger of
extinction, while threatened species are those that have declined significantly in total numbers
and maybe on the verge of extinction in certain localities. Valuable species are naturally
rare or have been depleted by human activities to a level that puts them at risk. Bald eagles,
grey wolves, brown (or grizzly) bears, sea otters, and a number of native orchids and other
rare plants are considered either vulnerable or threatened.
Convention on International Trade in Endangered Species (CITES)
The 1975 Conventional International Trade in Endangered Species (CITES) was a
significant step towards worldwide protection of endangered flora and fauna. It regulated
trade in living specimens and products derived from listed species. India is a signatory to
this convention. The signatory countries unanimously agreed upon:
(i) That wild flora and fauna in their natural habitat is irreplaceable.
(ii) That the nations are aware of the ever-growing value of wild flora and fauna from
aesthetic; scientific, cultural and recreational viewpoint.
(iii) That people of all nations hold a collective responsibility of the protection of flora
and fauna.
(iv) That international cooperation is a must to prevent trade in endangered species of
plants and animals.
Special Projects
Project Tiger
A fast decline of the tiger population lead to the set up of a special task force in 1970
by the Indian Board for Wildlife to prepare an action plan to conserve the tiger population
in India. As a result ‘Project Tiger’ was launched on 1 April 1973 with the following objectives:
• To maintain a viable population of tigers for scientific, cultural and ecological
values.
• To preserve areas rich in biodiversity as a national heritage for the education and
enjoyment.
In 1973-74 nine Tiger Reserves were established to promote elimination of all forms of
human exploitation and disturbance from the core zones.
Gir Lion Project
The Asiatic lion is now confined to the Gir Forest of Gujarat. The sanctuary harbored
nearly 200 of them. The great reduction in the number was due to the increased threat from
overgrazing, depletion of prey species, etc. The Asiatic lion was in danger of being wiped out
either due to starvation, epidemics or human interference. In 1972 the State government
prepared a scheme for the management of the Gir Lion Sanctuary with proper guidelinesfor conservation. The Centre provided assistance for the protection and improvement of thehabitat.Himalayan Musk Deer ProjectThe musk deer (Moschus moschiferus) which was once found throughout the Himalayantract has terribly suffered due to its musk been used in the preparation of perfumes andmedicine. Secondly the habitat destruction brought about a sharp decline in their population.
A conservation project was therefore launched at the Kedarnath sanctuary in U.P.
Crocodile Breeding Project
The three varieties of crocodile population viz., gharial (cavialis gangeticus), the mugger
(Crocodylus palusstris) and the salt-water crocodile (Crocodylus porosus) witnessed a sharp
decline by the early 1970s. With the assistance of the UNDP, the Government of India
launched a crocodile breeding and management project. The project was initially launched
in Orissa in the year 1975. The project scheme was subsequently extended to U.P., Rajasthan,
W.B., T.N., A.P., Gujarat. Kerala, M.P., Maharashtra, Andamans, Assam, Bihar and Nagaland.
As a result the population of all the three species has considerably increased.
Project Elephant
The Project Elephant was launched with a view to protect and conserve the elephant
population of the country. Project Elephant aimed at restoring degraded habitats of elephants.
Creation of migration corridors, elimination of human interference and establishment of a
data base on the migration and population dynamics of elephants e.g. elephant habitat
restoration work was done in Rajaji National Park.
QUESTIONS
1. Write the Definition of the Biogeographically Classification of India in 300 words.
2. Write the Value of Biodiversity in the concept of Global.
3. What do you understand by the India as a Mega? Explain in your own words.
4. What is Diversity Nation?
5. Write short notes on Conservation of Biodiversity in India in 500 words

<<< Previous 
YamEen Uncategorized

4 Biodiversity and Conservation part 1

INTRODUCTION
Today most of us live in a socially and technologically evolved society where our exploitive
potential and knowledge of nature has increased academically. The problem is that our
contact with it has diminished morally. It may have diminished to such an extent as to be
dangerous to us and to the nature itself. Biodiversity is the vast array of all the species of
plants, animals, insects and the microorganisms inhabiting the earth either in the aquatic
or the terrestrial habitats. The human civilization depends directly or indirectly upon this
biodiversity for their very basic needs of survival–food, fodder, fuel, fertilizer, timber, liquor,
rubber, leather, medicines and several raw materials. This diversity’s the condition for the
long-term sustainability of the environment, continuity of life on earth and the maintenance
of its integrity.
Although our understanding of the earth’s organisms–its biological resources- is still
imperfect, there is no doubt that the abundance and diversity of living organisms provide
many benefits and make our world a beautiful and interesting place to live. Biodiversity is
generally described in terms of its 3 fundamental and hierarchically related levels of biological
organisms. These areGenetic diversity
It includes the genetic variations within species, both among geographically separated
populations and among individuals within single population.
Species diversity
It includes full range of species from micro organisms to giants and mammoth varieties
of plants and animals, e.g. single celled viruses and bacteria etc. and multi-cellular plants,
animals and fungi.
Ecosystems diversity
It studies variation in the biological communities in which species Jive, exist and
interact.

Because genes are parts of species, and the species make up ecosystems- the concept
of biodiversity reflects an interrelationship among its three components. Biodiversity is
distributed uniformly across the globe. It is substantially greater in some areas than in the
others. Generally, species diversity increases from the poles towards the tropics- for instance,
among the terrestrial systems, the tropical moist forests, which cover only 57% of the earth’s
land area, possess as much as over 50% of the world’s species.
LOSS OF BIODIVERSITY
Biodiversity is diminished or destroyed in a number of ways either by natural changes
or by human disruption. The loss of even a single species is considered as a tragedy as each
form of life is a natural storehouse of irreplaceable substances the genetic materials (Ehrlich
& Ehrlich, 1982). As species become extinct, the fine balance of nature is disturbed to great
extent. The loss of even a single species can alter a food chain/food web, i.e. ecosystem
disruption, and upset the delicate balance between one species that preys upon another.
Natural Causes
Species arise through processes of mutation, isolation, and natural selection. Evolution
can proceed gradually over millions of years or may occur in large jumps when new organisms
migrate into an area or when environmental conditions change rapidly. In a sense, species
that are replaced by their descendants are not completely lost. The much larger modern
horse, for instance, has replaced the tiny Hypohippus, but most of its genes probably still
survive in its distant offspring.
Human-Caused Extinction
Man has a long history of dependence on biological resource hence depletion of resources
is obvious. It has never been the pursuit of mankind to completely destroy other species, but
in a variety of ways through ignorance or carelessness, we have reduced biological abundance
and driven species into extinction. Man as a hunter in Stone Age may have been responsible
for the extermination of the “Mega fauna” of both America and Eurasia during the Pleistocene
era. Climatic change may have been partially or primarily responsible. Vast usage of bones
in Europe and Siberia provide enough evidence that our ancestors have hunted upon animals
mercilessly. The loss of species and ecosystems extracts a high price. The water, the air,
fertile soils and productive seas as a common resource are all products of healthy biological
systems. The scale of human impact on the global biodiversity is huge. It is considered that
man has disturbed his own life support system. Tropical forest areas or the world suffer a
great loss, which are disappearing at the rate of 17 million hectares (17 sq. kms.) every year
(UNEP report, 1992).
The estimation from the fossil record suggests that the average life of a species is about
4 million years. According to an estimate, if there are about 10 million species a year at a
moderate estimate, we are now likely to lose around 50,000 species a year over the next
decades. According to the IUCN Red Data Book, the following is a broad list of threatened
animals:

Table 4.1: List of Threatened Animals
Animal group No. of species
Mammals 507
Birds 1,029
Reptiles 169
Amphibians 57
Fish 713
Insects 1,083
Molluscs 409
Corals and sponges 154
Annelid worms 139
Crustaceans 126
In a large number of southern countries the seeds of biodiversity destructions were laid
during the colonial era. In India, for instance, large-scale commercial forestry started in
British colonial times speeded up the rate of forest exploitation for fodder, meat, milk and
coffee demand. Deforestation and biodiversity destruction to sustain life after independence
by our more recent ancestors added fuel to the fire. Our mental capabilities do not allow us
to accept the growing changing demand of time. We still experience a lot of dependence on
forest products especially for fuel wood. However, government has provided substitutes of
solar driven appliances for cooking and lighting. Still it has failed to decrease pressure on
wood resources.
Table 4.2. Direct and Indirect Impact of Humans on Biological Resources
Direct impact Indirect impact
Hunting and food Gathering Habitat destruction
Fishing Exotic species Introductions
Trade in Animal Products Diseases
Harvesting wild plants Pollution
Pet and scientific trade Genetic assimilation
Predator and pest control
1. Measuring Biodiversity
Diversity can be defined as the number of species found in a community. Hence,
biodiversity refers to the species richness of an area. Algorithms of biodiversity have been
developed to connote species diversity at different geographical scales as follows:
Alpha Diversity
It indicates the number of species in a single community. The index can be used to
compare the number of species in different ecosystem type.

Beta Diversity
It indicates the degree to which species composition changes along an environmental
gradient.
Gamma Diversity
It indicates the rate at which additional species are encountered as geographical
replacements within a habitat type in different localities.
2. Rio-geographic Classification of India
India has been classified into ten bio geographic zones by the Wildlife Institute of India
under the Government’s Bio-geographic Project Table 3.
Table 4.3: Bio-geographic Zones of India
S.No. Bio-geographic Zones Distribution
1. Trans- Himalaya Ladakh Mountains, Tibetan plateau.
2. Himalaya North-Western, Central, Western and Eastern
Himalayas
3. Desert Thar, Kachchh
4. Semi-arid Punjab plains
5. Arid Gujarat, Rajputana
6. Deccan Peninsula Central Highlands, Chhota Nagpur, Eastern Highlands,
Central Plateau, Deccan south
7. Gangetic Plain Upper and lower Gangetic plain
8. Coast West coast, East coast
9. North-East Brahmputra valley, North east hills
10. Island Andamans and Nicobar Group of Islands, Lakshwadeep
3. The Value of Biodiversity
Ecosystems and species provide an enormous range of goods and other services –
immediate as well as long term, material as well as spiritual and psychological – which are
vital to our well being. The values of the earth’s biological resources can broadly be classified
intoDirect Values
Consumptive and productive uses.
Food Resources: Grains, vegetables, fruits, nuts, condiments, tea-coffee, tobacco, liquor,
oil from plant resources; and meat, fish, egg, milk (and milk products), honey, etc. from
animal resources.
Other Resources: Medicine, fuel, timber, household accessories, fodder, fiber, fertilizer,
wool, leather, paint, resin, wax, thatch. Ornamental plants, rubber, creams, silk, feathers,
decorative items, etc.

Indirect Values
Non-consumptive uses and options for the future.
1. Carbon fixing through photosynthesis, which provides the support system for species.
2. Pollination, gene flow, etc.
3. Maintaining water cycles, recharging ground water, protecting watersheds.
4. Buffering from climatic extreme conditions such as flood and drought;
5. Soil production and protection from erosion;
6. Maintaining essential nutrient cycles, e.g. carbon, nitrogen, and oxygen and others.
7. Absorbing and decomposing pollutants, organic wastes, pesticides, air and water
pollutants;
8. Regulating climate at both macro and micro levels;
9. Preserving recreational, aesthetic, socio-cultural, scientific, educational, ethical and
historical values of natural environments.
(i) Consumptive Use. Man is mostly dependent on plant and animal resources for his’
dietary requirements. A major share of our food comes from domesticated crops
and animals. Still we derive major of food from wild species. A large section of
human population is dependent on food, which we gather from seas, and oceans
that is harvested from free roaming wild organisms. Seafood is rich in minerals and
vitamins and contains up to 60 percent of the protein. Unfortunately, deforestation,
hunting and clearing of forests, grazing and expansion of agricultural lands removes
potentially valuable food species and the wild ancestors of our domestic crops.
(ii) Productive Use. Trade and commerce industry is very largely dependent on forests.
Besides, timber, firewood, paper pulp, and other wood products, we get many valuable
commercial products from forests. Herbs of medicinal value. Rattan, cane, sisal,
rubber, pectins, resins, gums, tannins, vegetable oils, waxes, and essential oils are
among the products gathered in the wild form forest areas. Like Himalayan forests
serve as a storehouse of medicinal herbs, which are presently being used to cure
many diseases. Many wild species e.g. milkweeds, etc. are also being investigated
as a source of rubber, alkaloids, and other valuable organic chemicals.
(iii) Medicine. Many medicinal and aromatic plants are being exploited in the wild to
tap their potential for different ailment cure in the field of drug extraction e.g.
Hippophae rhamnoides, Ephedra Kerardiana. Dactylorrahiza hatageria etc. Besides,
they are being cultured in plantations and protected in wild to encourage in-situ
and ex-situ conservation viz. Valley of flowers, Rohtang in Kullu, Lahu & Spiti
Valley. Animal products are also sources of drugs, analgesics pharmaceuticals,
antibiotics, heart regulators, anticancer and ant parasite drugs, blood pressure
regulators, anticoagulants, enzymes, and hormones.
(iv) Ecological Benefits. Man cannot have control over nature in the wild. It can only
put “pressure on resources and pollute environment. Then what makes environment
act as a self-replenishing system with respect to resource generation and selfcleanliness. To answer this comes into picture the role of biological communities.
The processes of soil formation, waste disposal, air and water purification, nutrient
cycling, solar energy absorption, and management of biogeochemical and hydrological

are all beyond the scope of man’s control. Non-domestic plants, animals, and microbes
do this favor to mankind by maintaining ecological processes at no cost. These also
serve as a library of gene pool. Wild species of plants and animals exercise control
over disease-carrying organisms and in suppressing pests. Food chain explains how
nature keep a control over population of organisms wherein organisms of small size
and larger in number are consumed by organisms large in size and smaller in
number to next higher tropic level. Hence, preservation of natural areas and
conservation of wild species should be encouraged and practiced to restore the
biological wealth.
(v) Aesthetic Use Wild species of plants and animals have always appealed man’s .
psyche. Human society has evolved from his early habitat in the forests, which
abounds in flora and fauna. Till date his instinct to observe nature in the wild calls
him from socially and culturally an evolved society, as tourist from far and wide
places. Thousands of tourists visit national park, sanctuaries and forests throughout
the country and especially in mountainous areas. A glance of temperate grasslands
perhaps the most beautiful landscape pleases and comforts man. All domestic plants
have evolved from wild ancestors and food gathering is no longer a necessity for
man but still thousands enjoy hunting, fishing and other adventurous outdoor
activities that involve wild species. Such environment and playful exercise gives
man an opportunity to renew his pioneer skills, and be at mental ease after leading
a hectic day in today’s life. Man enjoys his surrounding by decorating it with
images of wild animals and plants.
(vi) Cultural Benefits. A particular species or community of organisms may have
emotional value for a group of people who feel that their identity is inextricably
linked to the natural components of the environment that shaped their culture.
This may be expressed as a religious value, or it may be a psychological need for
access to wildlife. In either case, we often place a high value on the preservation
of certain wild species.
(vii) Option Values. This refers to the use of various species for the benefit of mankind,
sometime in future. The hunt for various species under the scope of biotechnology.
is already underway for finding solutions to various environmental problems. The
environmental issues being addressed to be: pollution as a major problem, ways to
fight various disease viz., cancer, diabetes etc., AIDS and others.
4. Biodiversity at Global, National and Local levels
1.Global Initiatives for Biodiversity Assessment
The initiative for biodiversity assessment was taken long back in 1991 with the UNEP
Biodiversity Country Studies Project (consisting of bilateral and Global Environmental Facility
funded studies in developing countries) implemented in cooperation with donor countries
and UNDP. The preparation of it dates back to 1987. Nineteen studies have been completed
and several more are in the process of completion. The approach from gene to ecosystem was
initiated as a Research Agenda for Biodiversity, IUBS/SCOPE/ UNESCO, Paris (Sol brig,
1991). The agreed text of the Convention on Biological Diversity was adopted by 101
governments in Nairobi in May 1992, signed by 159 governments and the European Union
at the United Nations Conference on Environment and Development (UNCED) held at Rio
de Janeiro in June 1992. At present 174 governments is party to this convention. Apart from
this Global Biodiversity Strategy (1992), Global biodiversity; Status of the Earth’s Living
Resources (1992), Caring for the Earth; A Strategy for Sustainable Living (1991), Global
Marine Biological Diversity: A Strategy for Building Conservation into Decision Making
(1993), Norway/UNEP Expert Conference on Biodiversity (1993) and From Genes to
Ecosystems: A Research Agenda for Biodiversity (1991) are the milestones on the international
biodiversity initiatives. Many more nations are engaged in developing their own National
Biodiversity Strategies. Global Biodiversity Assessment (UNEP, 1995) estimates the total
number of animal and plant species to be between 13 and 14 million. It further records that
so far only 1.75 million species have been described and studied. Ecosystem diversity has
not been even reasonably explored as yet. Hence, there seems to be wide gap of knowledge
at global, regional and local levels.
Till recent past biodiversity conservation was thought to be limited to saving genes,
species and habitats but the implementation revolutionary policies and more awareness has
led to the emergence of a framework based upon saving biodiversity, studying and most
importantly using it sustainable. Reforms in the field of forestry, agriculture, technology,
international trade agreement and watershed management is required. Biodiversity is directly
or indirectly related to masses (researchers, government agencies, non-government agencies
and private sectors) ‘at all levels of development. Since we depend upon biodiversity our
various activities can be linked to its usage and conservation. Therefore, trade, economics,
population, land tenure, intellectual property rights and resource consumption & waste are
all related to biodiversity conservation. Hence, its sustainable use can be promoted through
information, ethics, knowledge and awareness.
2. Levels of Action
Need for biodiversity conservation is realized by all nations of the world because their
lies common interest of masses. Most of the resources do not belong to an individual, a
nation or a continent. They are simply global. Each and every member on the earth has
equal right over it. To limit the loss of biodiversity globally 4 major steps have been realized
important at national, regional and local levels.
(i) Global Environment Facility (GEF)
World bank, United Nations Development Programme (UNDP), United Nations
Environment Programme (UNEP) established the GEF in 1900 on a three-year
pilot basis. The GEF is expected to commit $ 400 million for the biodiversity
conservation issue.
(ii) International Biodiversity Strategy Programme (IBSP)
World Resources Institute (WRI), World Conservation Union (WCU), UNEP together
with more than 40 Governmental and non-Governmental organizations have
prepared the framework to drastically reduce the loss of biodiversity. This would
serve mankind on a more sustainable basis.
(iii) Convention on Biological Diversity (COBD)
Under the aegis of UNEP, more than 100 nations gathered during Earth Summit at
Brazil. This was accomplished to workout a legal framework for—
Governing international financial support for biodiversity conservation,
• The identification of international conservation priorities and
• Technology transfer for conservation and use of biodiversity.
(iv) Agenda 21
Developed through a series of inter-Governmental preparatory meetings with input from
a variety of non-Governmental processes including the Biodiversity Strategy Programme—
AGENDA 21 provides a plan of action on a number of issues including biodiversity.
INDIA AS A MEGA-DIVERSITY NATION
Lying at the junction of Agro-tropical, Euro-Asian and the Indo-Malayan biogeography
realms, India is a country of vast biodiversity in the world and quite a significant one all
over the globe. In fact, it is among the twelve “Mega diversity” countries in the world. India
is also a “Vavilov” centre of high crop genetic diversity–so named after the Russian agro
botanist N.I. Vavilov who identified about eight such centres around the world in the 1950s.
India, a mega-biodiversity country, while following the path of development, has been
sensitive to the needs of conservation. India’s strategies for conservation and sustainable
utilization of biodiversity in the past aimed at providing special status and protection to
biodiversity rich areas by declaring them as national parks. Wildlife sanctuaries, biosphere
reserves, ecologically fragile and sensitive areas. It has helped in reducing pressure from
reserve forests by alternative measures of fuel wood and fodder need satisfaction. by a
forestation of degraded areas and wastelands, creation of ex-suit conservation facilities such
as gene banks and eco-development. The challenges before India are not only to sustain the
efforts of the past but also further add to these efforts by involving people in the mission.
BIODIVERSITY ASSESSMENT: INITIATIVES IN INDIA
In a most recent attempt to map biogeographically regions, Rodgers and Pan war (1988)
attempted to define the biogeographically regions of India. The sub-continent has ten
biogeographically zones viz., Trans-Himalayan, Himalayan, Indian desert, Semi-Arid, Western
Ghats, Deccan Peninsula, Gangetic Plains, North East India, Islands and Coasts and not yet
defined zones for aquatic (freshwater and marine) ecosystems have been mapped. The Wildlife
Institute of India has converted these regions on Survey of India digital database.
India is rich in endemic flora and fauna. According to an estimate (Anon., 1983) about
30 per cent plant species are endemic to India. Areas rich in endemism are North Eastern
India, the Western Ghats and the North Western Himalayas. A small pocket of -local
endemism is also reported from Eastern Ghats (MacKinnon and MacKinnon, 1986). The
Project on Study, Survey and Conservation of Elidangered Plants (POSSCEF) has estimated
that about 3000-4000 plant species are under different degrees of threat (Nayar & Shastri,
1987). Recently, Ministry of Environment and Forests, Government of India has launched
a project viz., National Biodiversity Strategy and Action Plan (NBSAP) which envisages the
assessment and stock taking of biodiversity related information at various levels, including
distribution of endemic and endangered species and site-specific threats. Key features of
this project include emphasis on decentralized planning and use of interdisciplinary working
groups to involve all sectors concerned with biodiversity conservation.

Table 4.4: Wild Animal Diversity in India
S.No. Class World India % (Age) Endemism
1. Mammals 4,231 372 8
2. Birds 8; 400 1,175 4
3. Reptiles 5,375 399 33
4. Amphibian 2,000 181 62
5. Fishes 23,400 1,693 —
6. Insects 8,00,000 60,000 —
7. Molluscs 1,00,000 5,000 —
Source: Wildlife Institute of India WII, (1993).
Table 4.5: Wild Plants Diversity in India
S.No. Flora World India % of Endemism
1. Angiosperm 2,50,000 15,000 6
2. Gymnosperm — 64 —
3. Pteridophytes — 1,022 —
4. Bryophytes — 2,584 —
5. Algae — 2,500 —
6. Fungi -— 23,000 —
7. Bacteria — 850 —
8. Lichens — 1,600 —
Source: Biodiversity in India, R.R. Rao (NBRI) Lucknow, 1984.
HOTSPOTS OF BIODIVERSITY
Areas with rich biodiversity and exhibiting high levels of endemism, which are under
immediate threat of species extinction and habitat destruction, are recognized on priority
basis worldwide for conservation practices and are known as hot spots. 12 hot spots identified
world over represent 14% of world’s plant species in only 0.2% of its -total land surface. 12
mega diversity nations (Mexico, Columbia, Brazil, Peru, Ecuador, Madagascar, Indonesia.
Malaysia. India, China and Australia) contain 60-70 % of the world’s biodiversity. Out of the
total hot spots worldwide two lies in India. These are represented by North-eastern Himalayas
(Khasi jaintia hills and the lower Himalayan slopes embracing areas of Arunachal Pradesh,
Assam, Meghalaya, Nagaland and Tripura) and Western Ghats region in the south. These
fall under heavy rainfall zones.
The rain forests of the Western Ghats and the eastern Himalayas consist of very dense
and lofty trees with a multitude of species occurring in the same area. Hundreds of species


of trees can be identified in a hectare of land besides mosses, ferns, epiphytes, orchids,
lianas and vines, herbs shrubs and fungi that make up this. region the most diverse habitat.
Giant trees stretch up towards the sun. Buttress roots, anchored within the soil, support the
smooth straight trunks, which rise 30 mts. or more before branching out. The spreading
crowns effectively block outmost of the light from the light from the ground beneath.
Dipterocarpus sp. predominates in these forests and this type of vegetation is often called
Dipterocarpus forests.
1. North-east Himalayas
From the dense evergreen and semi-evergreen vegetation of the foothills in the Eastern.
Himalaya, the character of vegetation changes at altitudes of 1525 m to 1830 m. Qaks,
magnolias, laurels and birches covered with moss and ferns replace the sal, silk-cotton trees
and giant bamboos of the foothills. At about 2745 m to 3660 m one enters the coniferous
forest of pine, fir yew and junipers. There is undergrowth of scrubby Rhododendrons and
dwarfs bamboos. Due to high humidity and much higher rainfall, lichens, mosses, orchids
and other epiphytes cover the tree trunks. The animal life in the temperate region is
different from the western Himalaya and is characterized by the presence of Indo Chinese
fauna. The red panda, hog badgers, ferret badgers, crestless porcupines are typical species
of this area. Three kinds of goat antelopes also occur in the eastern Himalaya and are
relatives of the European chamois. Goral is a smaller goat antelope found throughout the
tract on rugged grassy slopes and on rocky grounds near the conifers forests.
2. Western Ghats
The Western Ghats and the central belt lying to the west of it, is a region of very high
rainfall and is characterized by evergreen vegetation, its flora and fauna being a kin to the
evergreen rain forest of north-eastern India. Among the macaques the lion tailed (Macaca
silenus) is one of the world’s most endangered primates, surviving in the evergreen forests
of the Western Ghats of south India, its total population is estimated to be about 800 only.
In the langur group, the nilgiri ‘Iangur’ (Presbvtis johni) is a multihabitat species occurring
in addition to the shoals, in the temperate evergreen forests above 1700 m altitude in the
Western Ghats. A number of climbing animals have evolved gliding mechanisms and are
particularly characteristic of these forests. Among these are the flying squirrels. The other
characteristic species of the Western Ghats are the Nilgiri mongoose, the stripnecked
mongoose, the malabar civet and the spiny mouse.
The flora and fauna of these evergreen regions have not been fully explored. Being a
store house of a large variety of plants and animals, these forests represent one of the
richest gene pool resources of flora and fauna in the country. Though a large number of such
forests have not been destroyed for various plantation crops like rubber, cocoa, coffee etc.,
whatever virgin forests remain have to be specially protected as in the Silent Valley of
Kerala or the rich orchid belt of the north-eastern Himalayas in Arunachal Pradesh and
Sikkim.
THREATS TO BIODIVERSITY
The biggest reason for the current increase in extinctions is habitat loss. Destruction
of tropical forests, coral reefs, estuaries. Marshes, and other biologically rich ecosystems

threaten to eliminate thousands or even millions of species in a human-caused mass extinction
that could rival those of geologic history. By destroying habitat, we eliminate not only
prominent species but also many obscure ones of which we may not even be aware. Over
harvesting of food species is probably the most obvious way in which humans directly
destroy biological resources. There are many, historic examples of human disturbances of
natural systems. Once-fertile areas have become deserts because of unsound forestry, grazing,
and agricultural practices. Technology nm” makes it possible for us to destroy vast areas
even faster than in the past. Undoubtedly the greatest current losses in terms of biological
diversity and unique species occur when tropical moist forests are disrupted.
1. Main Causes of Threat to Species
It is well known now that several plant species have become extinct due to certain
natural phenomena, such as land upheavals, volcanic eruptions, glaciations, protracted periods
of rain or drought, spreading of desert lands, forest fires and eutrophication in the geological
past. While such natural processes in the past had no doubt led to the extinction of flora,
the resulting new environmental conditions had also resulted in the evolution and speciation
of new flora and migration of floral elements.
But, in recent times man with his anthropogenic associates and other factors or practices
such as fire or ‘slash and burn’ for shifting cultivation (also called as ‘jhum’ or ‘podu’
cultivation in India), grazing by cattle and by several other mechanical means, has suddenly
accelerated disastrous condition in natural ecosystems. Besides, commercial exploitation of
entire plants, roots, rhizomes, tubers bulbs seeds and fruits has been the prime cause of
depletion of more important wild economic plants throughout the world for lucrative financial
gains, in the trade which flourishes both by legal and illegal means Rauvolfia serpentina,
Coptis teeta, Dioscorea sp. and Podophylum hexandrum serve as good examples.
(i) Habitat Destruction
Deforestation has been one of the major causes for the depletion of wildlife. With the
increase in human population and the growing need for resources, forests were cleared or
for agricultural operations, for human habitation and for grazing their livestock. Technological
advance and human progress had a direct bearing on the exploitation of natural resources.
Forest trees were cut to yield timber for building houses, for making furniture and for
collecting wood as fuel. Industries made a heavy demand on forest resources such as wood
for paper- making, exploitation of gums and resins, mining. of forestland for mineral ores,
building materials, etc.
Habitat destruction thus has an adverse impact on wildlife as it leads to the loss of an
environment, which provides them food and breeding grounds or nesting sites to facilitate
rearing of their young ones. Wild animals are left with no alternative but to adapt, migrate
or perish. Widespread habitat loss all over the country has diminished the population of
many species, making them rare-and endangered. In our race for progress and prosperity
we have disturbed the delicate balance of Nature.
(ii) Hunting and Poaching
Uncontrolled hunting of wildlife for pleasure, food, furs. Skins, horns, tusks, etc. pose
a serious threat to the survival of wildlife. In India, the Cheetah was hunted to extinction.
The illegal trade in animal skins has been responsible for the destruction of a large number

of tigers, leopards, deer, fishing cat, crocodiles and snakes, as well as birds with beautiful
plumage. Elephants were hunted for ivory. The rhinoceros was killed for its horns because
of the superstitious belief that it contained aphrodisiac properties. There are laws in the
country to prevent such illegal trade, but unscrupulous elements, traders and exporters
often violate these. Added to this is the practice of trade in exotic mammals, birds and
reptiles and use of wild animals in biomedical research.
(iii) Pollution
Pollution of air, water and soil due to various industrial activities not only affect our
health, but the health and well being of animal population also. Industrial effluents one
reaching water bodies adversely affect aquatic life. Pesticides like DDT and Dieldrin are
very harmful. These have a major effect particularly sea birds and their eggs. Oil pollution
is another serious problem affecting the seas through leakage from cargo ships or accidents.
Besides there are other numerous factors that affect wildlife population, which are
mostly anthropogenic. Introduction of exotic species, unhealthy agricultural practices, diseases
introduced by domesticated animals, silting of rivers, floods and droughts are a few to name
some. These all have somehow contributed to the process of endangering animal species.
2. Man and Wildlife Conflict
Man by virtue of his nature is destructive and self-centred despite the fact that he is
known as social animal. Until he realizes the need of time no rules and regulations may
help. The exploitation of forests and wildlife or rare species for commercial purposes should
be stopped. A good tiger skin is worth more than five thousand rupees. The tusks of an
elephant and the skin of big cats also fetch a good prize. The horns of rhinoceros carry a
highly fancy prize. This high market value has lead to unlimited slaughter of these animals.
ENDANGERED AND ENDEMIC SPECIES OF INDIA
The Forest administration in India is more than 100 years old. Efforts to identify plant
species as a part of wildlife and to recognize the importance for providing special protection
to endangered plant species have so far been negligible. The extinction of certain attractive
animals stimulated efforts to protect fauna, but no special heed was given to flora. The word
‘Wildlife’ had till recently been considered synonymous with animal life and consequently,
conservations and naturalists have their attention only to conservation of animal species.
It was only in the year 1968 at an International Conference (UNESCO 1968) that the
problem of conservation of flora and fauna was appreciated and several recommendations
were made urging the International Biological Programme (IBP), .the International Union
for Conservation of Nature and Natural resources (IUCN) and various international and
national organizations to initiate studies in to the problems involved, particularly the problem
of protecting and preserving wild fauna and flora in their natural habitat/ecosystems
establishing nature reserves.
Later at the 10th General Meeting of the IUCN, the Survival Service Commission
reviewed the status of endangered species of plants and their habitats. The recent
promulgations of the United States Endangered Species Act (1973), the UK Wild Creatures
and Wild Plants Act. (I975), development of international conventions on conservations
(Wetlands Convention) and the setting up of Biological Records Centre of the Nature
Conservancy, UK, and threatened plants, orchids, cycads tree wide awakening of the need
for the conservations, preservation and protection of floras of the world.
According to the Volume 5 of Red Data Book on angiosperms started by the Survival
Service Commission of the IUCN in the year 1970 (Melville, 1970), it is estimated that out
of the total of three lakes (0.3 million) species of plants in the world, over 20,000 were in
the category of either endangered or vulnerable and threatened with extinction by the year
2000 A.D.The following categories of rare species have been recognized by the IUCN, mainly
based on (i) present distribution, (ii) decline in number of time, (iii) abundance and quality
of natural habitats, and (iv) biology and potential value of the species.
Endangered (E)
Species in danger of extinction and whose survival is unlikely if the casual factors
continue operating, included are species whose numbers have been reduced to a critical level
or whose habitats have been so drastically reduced that they are deemed to be in immediate
danger of extinction.
Vulnerable (V)
Species believed likely to move into the endangered category in the near future if the
casual factors continue operating. Included are species, of which most or all the populations
are decreasing because of over-exploitation, extensive destruction of habitat or other
environmental, disturbance species with populations that have been seriously depleted and
whose ultimate security is not yet assured; and species with populations that are still
abundant but are under threat from serious adverse factors throughout their range.
Rare (R)
Species with, small world populations that are not at present endangered or vulnerable,
but are at risk. These species are usually localized within restricted geographical areas or
habitats or thinly scattered over a more extensive range.
Threatened (T)
Threatened is used in the conservation context for species which are in one of the
categoriser Endangered, Vulnerable and Rare. Some species are marked as threatened
where it is known that they are Endangered, Vulnerable or Rare, but there is known that
they are Endangered, Vulnerable or Rare, but there is not enough information to say which
of these three categories is appropriate.
Out of Danger (O)
Species formerly included in one of the above categories, but which are now considered
relatively secure because effective conservation measures have been taken or the previous
threat to their survival has been removed.
Indeterminate (I)
Species that are suspected of belonging to one of the first three categories, but for which
insufficient information is currently available.



<<< Previous                                                             Next >>>
YamEen Uncategorized

3 Environmental Science : Ecosystem part 3

(2) Again 21 per cent of this energy, or 23 gcal/cm2/yr (show on the bottom as respiration)
is consumed in metabolic reactions of autotrophs for their growth, development,
maintenance and reproduction.
(3) 15 gcl/cm2/yr are consumed by herbivores that graze of feed on autographs-this
figure amounts to 17 per cent of net autotroph production.
(4) Decomposition is 3 gcal/cm2/yr which amount to be 3, 4 per cent of net production.
(5) The remainder of the plant material, 70 gcal/cm2/yr of 79.5 per cent production, is
not utilised. It becomes part of the accumulating sediments. Apparently much more
energy is available for herbivory than is consumed.
We may conclude the following conclusions
(1) Various pathways of loss are equivalent to and account for total energy capture of
the autotrophs i.e. gross production.
(2) The three upper ‘fates’ i.e. decomposition, herbivory and not utilized collectively are
equivalent to net production.
(3) Of the total energy which is incorporated at the herbivory level, i.e. 15/ gcal/cm2yr,
30 percent of 4.5 gcal/cm2/yr is used in metabolic reactions.
(4) In this way more energy is lost via respiration by herbivores (30 percent) than by
autotrophs (21 percent),
(5) Considerble energy is available for the carnivores, namely 10.5 gcal/cm2/yr
or 70-per cent. It is not entirely utilized, merely 3.0 gcal/cm2/or 28.6 per cent
of net production passes to the carnivores. This utilization of resources is
evidently more efficient than the one, which occurs at autotroph-herbivore
transfer level.
(6) At the carnivore level the consumption in metabolic activity is about percent of the
carnivores energy intake.
(7) The remainder becomes part of the un-utilized sediments;
(1) There is Noe-way Street along which energy moves (unidirectional flow of energy.
(a) The energy that is captured by the autotrophs does not revert back to solar
input.
(b) The energy which passes does not pass back to the autotrophs. It moves
progressively through the various trophic levels. As such, it is no longer
available to the previous level. Since there is one-way flow of energy, the
system would collapse in case the primary source, the sun, were cut off.
(2) Secondly, progressive decrease in energy level is seen at each trophic level. This
decrease is accounted as under:
(i) By the energy dissipated as heat in metabolic activities.
(ii) Measured here as respiration coupled with unutilized energy.
Below is a figure after Epodum (1963)

Trophic levels
G reen plants
producers
Consum ers
2
Herbivores
NU NA
3
Carnivores
Total light
1 and L
heat
3000 — 15000 15 1.5 0.3
R R R
L
A PN P 2 P 3
K cal/m /da 2 y
L
P
N 1 A
A
P 1 P
1
P or
G
Fig. 3.2 Energy flow diagram
This is a simplified energy flow diagram
(1) The diagram depicts three trophic levels. Boxes numbered 1, 2, 3 in a leaner food
chain exhibit these.
(2) L. shows total energy input (3000).
(3) LA shows light absorbed by plant cover (1500).
(4) P.G. shows gross Primary production.
(5) A shows total assimilation.
(6) Pn shows net primary production.
(7) P shows secondary (consumer) production.
(8) Nu shows energy not used (stored or exported).
(9) NA shows energy not assimilated by consumers (egested).
(10) R shows respiration.
Some more elucidation of the figure is as under:
(1) The ‘boxes’ represent the trophic levels
(2) The ‘pipes’ depict the energy flow in and out of each level.
Energy inflows balance outflows
The first law of thermodynamics requires it. The energy transfer is accompanied by
dispersion of energy into unavailable heat (i.e. respiration). The second law requires it.

It is very simplified energy flow model of three trophic levels
Apparently the energy flows is greatly reduced at each successive trophic level from
producers to herbivores and then to carnivores. It is reflected that at each transfer of energy
from one level to another, major part of energy is lost as heat or other form. The energy flow
is reduced successively. We may consider it in either term as under:
(1) In terms of total flow (i.e. total energy input and total assimilation).
(2) In terms of secondary production and respiration components.
In this way of the 3,000 Kcal of total light, which falls upon the green plants,
approximately 50 per cent (1500 Kcal) is absorbed. Only 1 per cent (15 Kcal) of it is converted
at first trophic level. Thus net primary production comes to be at 15 Kcal. Secondary
productivity (P2 and P3 in the diagram) is about 10 percent at successive consumer trophic
levels in other words at the levels of herbivores and the carnivores. However, efficiency may
be sometimes higher as 20 per cent, at the carnivore level as shown (or P3=0.3 Kcal) in the
diagram.
It may be concluded from the above studies as under:
(1) There is a successive reduction in energy flow at successive trophic levels. Thus
shorter the food chain, greater would be the available food energy. The reason is
with an increase in the length of food chain, there is a corresponding more loss of
energy.
(2) With a reduction in energy flow (shown as ‘pipes’ in the diagram) at each successive
trophic level, there is also a corresponding decrease in standing crop or biomass
(shown as ‘boxes’ in the diagram). However, it does not mean that there exists any
correlation between the biomass and energy. Indeed energy as taken here represents
rate functions or production rates. The relationships between biomass and content
are not fixed. They may differ according to the situations. For example, one gram
of an algae (lesser biomass) may be equal to many grams (more biomass) of a forest
tree leaves as the rate of production of the algae is higher than that of tree leaves.
Y-shaped energy flow model-Two channel energy flow model
Following the example of Lindeman, several authors described energy flow modes for
different kinds of ecosystems. Two illustrations are here:
(1) Teal (1957) prepared an energy flow diagram of Root Spring in U.S.A.
(2) H.T. Odum (1957) prepared energy flow model for Silver Springs, Florida, U.S.A.
(3) 30, 810 Kcal/m2 y remained for net production.
In model given by Teal (1957) for Root Springs, most of the energy rich material eaten
by heterotrophs entered the systems as plant debris. On the other hand in the model given
by H.T. Odum (1957) for Silver Spring, most of the heterotroph’s food in food chain was
produced by green with in some systems heterotrophs consume living plants while in others
they feel on dead plant parts (detritus).
(1) In Root Springs, the chain began with dead plant parts.
(2) In Silver Springs the chain began with live plant parts.


On the basis of the studies E.P. Odum pointed out that in nature there are present two
basic food chains in any system:
(1) The grazing food chain beginning with green plant base going to herbivores and
then to carnivores, and
(2) The detritus food chain beginning with dead organic matter acted by microbes,
then passing to detritivores and their consumers (predators).
The figure given below present one of the first published energy flow models as pioneered
by H.T. Odum in 1956.
P
1
P
P3 1
P
P N
Fig. 3.3 First Energy Flow Model (1956)
The above figure illustrates energy flow in a community with a large import and
smaller export of organic matter.
P indicates gross primary production; PN indicates net primary production. P2.
P
2……………P5 indicate secondary production at the shown levels.
Gross Primary production GPP = Total photosynthetic C fixation Autotrophic Respiration,
RA = GPP-NPP
Net primary Production, NPP-RA
Heterotrophic Respiration, RH = respiration of consumers and decomposers.
Ecosystem Production, NEP = GPP-RE

The three major steps in energy flow correspond to:—
(a) Exploitation efficiency,
(b) Assimilation efficiency,
(c) Net production efficiency.
The product of the assimilation net production efficiencies gives gross production
efficiency i.e. by the fraction of the eaten material eventually transformed into consumer
biomass. The whole food web may be taken to be the product of the gross production
efficiency and the exploitation efficiency. The various kinds of energetic efficiencies can be
defined as under:
Exploitation efficiency = Ingestion of food/prey production.
Assimilation efficiency = Assimilation/ingestion;
Net production efficiency = Production/assimilation.
Ecological efficiency = Exploitation efficiency × Assimilation efficiency × Net
production efficiency;
= Consumer production/prey production;
= Production/ingestion.
Gross production = Production/ingestion.
In animals, rate of production appears to depend on body mass. Per unit body mass,
small animals are found more productive than big animals. Again invertebrates are less
productive than mammals. Molluscs, annelids, isopods, and insects are invertebrates of
intermediates size between copepods and echinoids.
Some conclusions regarding energy flow in the ecosystem are as under:
There is no quantitative relationship between the production of a certain trophic level
and the production of the next lower trophic level (both in calorific terms) except for the very
high or very low values of the former. This applies to the “phytoplankton-filter feeders” and
as well as “filtrators-invertebrate predators” trophic links in the plankton food chain.
The utilization of primary production in pelagic zone often depends on the nature of
dominant species of producers and consumers. In a system containing phyto-planktonic
algae-macroconsumers effective utilization occurs mostly via grazing. In the case of larger
algae and smaller consumers, primary production is mainly utilized via bacterial detritus
medium.
The energy transfer efficiency from the filtrator’s trophic level to their invertebrate
predators is often higher than from phytoplankton to filtrators.
ECOLOGICAL SUCCESSION-MEANING AND TYPES
Meaning of Succession
Biotic communities are not static. Instead they change through time. This change can
be understood on several levels. The simplest level is the growth, interaction and death of
individual organisms as they pass through their life cycles, affected by the cycles of seasons
and other natural phenomena. Some other levels of community change act over longer time

spans and that account for much larger changes in community composition and structure.
These include ecological succession and community evolution.
It is evident from the above said that the term succession denotes a sequence of changes
in the species composition of a community, which is generally associated with a sequence
of changes in its structural and functional properties. The term is generally used for temporal
sequence (in terms of years, decades or centuries) of vegetation on a site; although only
short term changes can be observed directly and the long term ones are inferred from
spatial sequences.
The changes associated with succession are usually progressive or directional. This fact
enables one to predict which species are likely to replace other in the course of a succession.
Sucession tends to continue until the species combinations best suited to the regional climate
and the particular site are established.
Historical Background
The basic idea of succession was in the beginning forwarded by Anon Kerner (1863) in
his book “Plant Life of the Danube Basin” during the description of the regeneration of a
swamp forest. The term ecological succession was first of all used by Hult (1885) in the study
of communities of Southern Sweden. H.C. Cowles held that communities are not static but
dynamic. This changed understanding be visualized as an orderly, directional and predictable
phenomenon. It was added that succession is autogenic i.e. regulated by biotic interactions
within the community. The central foundation of the classical theory was that early
communities alter the environment to their detriment and favour later successional
communities. It was revealed by the later studies that allogenesis was perhaps more common
and dominant than autogenesis; allogenesis means the control of community dynamics by
factors originating outside the community boundaries.
The succession of animals on these dunes was studied by ‘Shelford (1913). Later on,
Olson (1958) restudies the ecosystem development on these dunes and has given us an
updated information about it. Federick Clements (1907-1936) elaborates the principles and
theory of succession. He proposed the monoclimax hypotesis of succession. During the later
years certain other hypotheses were proposed by various ecologists to explain the nature of
climax communities: for example, polyclimx hypothesis by Braun-Blanquet (1932) and Tansley
(1939): climax pattern hypothesis by Whittaker (1953), Mac intosh (1958) and Sellack (1960):
and stored energy theory of information theory by Fosberg (1965, 1967) and Odum (1969).
Odum (1969) defined succession in terms of 3 parameters, viz.:
(1) Succession is an orderly process of reasonable directional and fairly predictable
community development;
(2) Succession results from modification of the physical environment by a community,
i.e. succession is largely community controlled.
(3) Succession culminates in a stabilized ecosystem in which maximum biomass and
symbiotic function between organisms are maintained per unit of available energy
flow. Whittaker (1975), held that through the course of succession community
production, height and mass, species-diversity, relative stability, and soil depth and
differentiation generally all tend to increase. The culminating point of succession
is a climax community of relatively stable species composition and steady-state
function, It is adapted to its habitat. It is permanent in its habitat if it is not
disturbed.

Illustrations
Ecological succession can be explained with the help of illustrations as under: –
1. Lake
When a lake fills with silt it changes gradually from a deep to a shallow lake of pond,
then to a marsh, and beyond this, in some cases, to a dry-land forest.
2. Crop field
When a crop field is deserted or a forest is severely burned over, it is just like a plot
of bare ground and a series of plant communities grow up there and replace on another –
firest annual weeds, then perennial weeds and grasses, then shrubs, and trees-until a forest
ends the development.
In this way, ecological succession is an orderly and progressive replacement of one
community by another until a relatively stable community, called the climax community,
occupies the area.
(1) In the first example the principal cause of the change in the community was
physical process-the filling in of the lake with silt.
(2) In the second example, a principal cause was the growth of plants on an existing
soil.
Development
Ecological succession develops as under:
1. Pioneers
The first organisms to become established in an ecosystem undergoing succession are
called pioneers; the stable community that ends the succession is termed the climax
community.
2. Sere
The whole series of communities which are involved in the ecological succession at a
given area. For example, from grass to shrub to forest, and which terminates in a final
stable climax community, is called as sere.
3. Seral stage
Each of the changes that take place is a seral stage.
4. Community
Each seral stage is a community, although temporary, with its own characteristics. It
may remain for a very short time or for many years.
Classification of Seres
Seres are sometimes classified according to the predominant force that is bringing them
about. These forces are biotic, climatic, physiographic, and geologic. Their resultant seres
are commonly called bioseres, cliseres, eoseres and geoseres.
Types of Succession
The succession may be of the following two types:

1. Primary Succession
Primary Succession is the process of species colonization and replacement in which the
environment is initially virtually free of life. In the other words the process starts with base
rose or sand dune or river delta or glacial debris and it ends when climax is reached. The
sere involved in primary succession is called presere.
2. Secondary Succession
Secondary succession is the process of change that occurs after an ecosystem is disrupted
but not totally obliterated. In this situation, organic matter and some organisms from the
original community will remain; thus the successional process does not start from scratch.
As a result, secondary succession is more rapid than primary. It is seen in areas burned by
fire or cut by farmers for cultivation. The sere involved in secondary succession is called
subsere.
Types of Succession
The primary and secondary successions may be of three types. The classification is on
the basis of the moisture contents:
(a) Hydrach of Hydrosere
The succession when starts in the aquatic environment such as ponds, lakes, streams,
swamps, bogs, etc. is called hydrach or hydrosere.
(b) Mesarch
The succession when begins in and area, where adequate moisture is present, is called
mesarch.
(c) Xerach or Exerosere
The succession when starts in xeric or dry habitat having minimum amounts of moisture,
such as dry deserts, rocks, etc. is called xerach. A temporary community in an ecological
succession on dry as sterile habitat is called xerosere. It may be of three types as under:-
(1) Iithosere-succession initiating on sand;
(2) Psammosere-succession initiating on sand;
(3) Halosere-succession starting on saline water or soil.
Autogenic Community
Autogenic community is the succession progressing entirely as a result of interactions
of the organisms and their environment (i.e. “driving force” is internal to the community)
for example succession on sand dunes.
Allegonic Community
Allegonic community is the succession moving under the influence of external factors,
as input of nutrients, succession in a small pond or bog.
Autotrophic And Heterotrophic Succession
Sometimes, succession is classified as autotrophic and heterotrophic on the basis of
community metabolism:
(1) Autotrophic succession is characterized by early and continued dominance of
autotrophic organisms like green plants. It begins in a predominantly inorganic
environment. In it the energy flow is maintained indefinitely.
(2) Heterotrophic succession is characterized by early dominance of heterotrophs, such
as bacteria, actinomycetes, fungi and animals. This sort of succession begins in a
predominantly organic environment and there is a progressive decline in the energy
content.
Serule
The miniature succession of micro-organic environment and different types of fungi on
the fallen logs of the decaying wood, tree bark, etc. is called serule.
Drury and Nisbet (1973) classified succession into three main types:
(a) Category I includes many classical types of secondary succession and some primary
successions. It involves temporal sequences on one site with climate and
physiography mostly remaining stable.
(b) Category II includes many primary successions (especially those in ponds and
lakes) and a few secondary successions. In this, temporal sequences on site with
the local environment changes under the influence of such external factors as
climate, erosion, drainage, nutrient inputs, etc.
(c) Category III includes those changes, which take place over long (geological) time
scale, and cover spatial sequences on adjacent sites.
Common attributes of Ecological Succession
Some Common attributes of ecological succession are as under:
Table 3.3 Ecosystem Attributes
Ecosystem attributes Development Stage Mature Stages
Community Energetics More or less than 1 About 1 (or
Gross production/community respiration approaches 1)
Gross production/standing crop biomass High Low
Biomass supported/unit energy flow Low High
Net community production (yield) High Low
Food Chains Mainly grazing; detrital Predominantly linear
web like
B. Community Structure
Total organic matter Less More
Inorganic nutrients Extrabiotic Intrabiotic
Species diversity Low High
Biochemical diversity Low High
Spatial heterogeneity and stratification Poor Well-organized
(Contd.
C. Life History
Niche specialization Broad Narrow
Organism size Small Big
Life Cycle Simple & short Complex, Long
D. Nutrient Cycling
Mineral cycles Open Closed
Nutrients exchange rate Rapid Slow
Role of detritus in nutrient regeneration
E. Selection
Growth For rapid growth “I” Mainly for feedback
selection control (k-selection
Quantity Quality
F. Overall Homeostasis
Internal symbiosis Undeveloped Developed
Nutrient conservation Poor Good
Stability (resistance to external perturbations Poor Good
Entropy High Low
SUCCESSION: GENERAL PROCESS, CLIMAX
General Process
The process of succession being with a bare area or nudation formed by several reasons,
such as volcanic eruption, landslide, following sequential steps.
1. Nudation
The process of succession begins with a bare area or nudation formed by several reasons,
such as volcanic eruption, Landslide, flooding, erosion, deposite, fire, disease, or other
catastrophic agency. Man also may be reason of formation of new lifeless bare areas for
example, walls, stone quarrying, burning, digging, flooding large land areas under reservoirs,
etc.
2. Invasion
The invasion means the arrival of the reproductive bodies or propagules of various
organisms and their settlement in the new or bare area. Plants are the first invaders
(pioneers) in any area the animals depend on them for food. The invasion includes the
following three steps:
(a) Dispersal or migration: The seeds, spores or other propagules of the species
reach the bare area through air, water or animals.
(b) Ecesis: Ecesis is the successful establishment of migrated plant species into the
new area. It includes germination of seeds or propagules, growth of seedlings and
starting of reproduction by adult plants.
(c) Aggregation: In this stage, the successful immigrant individuals of a species
increase their number by reproduction and aggregate in large population in the
area. As a result individuals of the species come close to one another.


QUESTIONS1. Explain the concept of an ecosystem with their structure and function.
2. Write the procedures of ecosystem in your own words.
3. Draw an energy flow in the ecosystem.
4. What is Ecological Succession, and food chain ? Explain in your own words.
5. Write short notes on:
(a) Ecological pyramids,
(b) Types and characteristics,
(c) Structure and functions of ecosystems.



YamEen Uncategorized

3 Environmental Science : Ecosystem part 2

FUNCTION OF AN ECO-SYSTEM
For a fuller understanding of ecosystems a fuller understanding of their functions
besides their structures is essential. The function of ecosystems includes, the process how
an eco-system works or operates in normal condition.
From the operational viewpoint, the living and non-living components of ecosystem are
interwoven into the fabric of nature. Hence their separation from each other becomes
practically very much difficult. The producers, green plants, fix radiant energy and with the
help of minerals (C, O, N, P, L, Ca, Mg, Zn, Fe etc.) taken from their soil and aerial
environment (nutrient pool) they build up complex prefer to call the green plants as converters
or transducers because in their opinion the terms ‘producer’ form an energy viewpoint which
is somewhat misleading. They contend that green plants produce carbohydrates and not
energy and since they convert or transducer radiant energy into chemical form, they must
be better called the converters or transducers. However, the term’ producer’ is so widely
used that it is preferred to retain it as such.
While considering the function of an ecosystem, we describe the flow of energy and the
cycling of nutrients. In other words, we are interested in things like how much sunlight
plants trap in a year, how much plant material is eaten by herbivores, and how many
herbivores carnivores eat.
Functions of Eco-system
The functions of Ecosystem are as under:
1. Transformation of Solar Energy into Food Energy
The solar radiation is major source of energy in the ecosystem. It is the basic input of
energy entering the ecosystem. The green plants receive it. And is converted into heat
energy. It is lost from the ecosystem to the atmosphere through plant communities. It is
only a small proportion of radiant solar energy that is used by plant to make food through
the process of photosynthesis. Green plants transform a part of solar energy into food energy
or chemical energy. The green plants to develop their tissues use this energy. It is stored
in the primary producers at the bottom of trophic levels. The chemical energy, which is
stored at rapid level one, becomes the source of energy to the herbivorous animals at trophic
level two of the food chain. Some portion energy is lost from trophic level one through
respiration and some portion is transfereed to plant-eating animals at trophic level two.
2. The Circulation of elements through Energy Flow
It is seen that in the various biotic components of the ecosystem the energy flow is the
main driving force of nutrient circulation. The organic and inorganic substances are moved
reversibly through various closed system of cycles in the biosphere, atmosphere, hydrosphere
and lithosphere. This activity is done in such a way that total mass of these substances
remains almost the same and is always available to biotic communities.
3. The Conversion of Elements into Inorganic Flow
The organic elements of plants and animals are released in the under mentioned ways:
(i) Decomposition of leaf falls from the plants dead plants and animals by decomposers
and their conversion into soluble inorganic form.
(ii) Burning of vegetation by lighting, accidental forest fire or deliberate action of man.
When burnt, the portions of organic matter are released to the atmosphere and
these again fall down, under the impact of precipitation, on the ground. Then they
become soluble inorganic form of element to join soil storage, some portions in the
form of ashes are decomposed by bacterial activities.
(iii) The waste materials released by animals are decomposed by bacteria. They find
their way in soluble inorganic form to soil storage.
4. The Growth and Development of Plants
In the biogeochemical cycles are included the uptake of nutrients of inorganic elements
by the plants through their roots. The nutrients are derived from the soil where these
inorganic elements are stored. The decomposition of leaves, plants and animals and their
conversion into soluble inorganic form are stored into soil contributing to the growth and
development of plants. Decompositions are converged into some elements. These elements
are easily used in development of plant tissues and plant growth by biochemical processes,
mainly photosynthesis.
5. Productivity of ecosystem
The productivity of an ecosystem refers to the rate of production i.e. the amount of
organic matter, which is accumulated in any unit time. Productivity is of the following types:
(1) Primary productivity: It is associated with the producers which are autotrophic,
Most of these are photosynthetic, Thus, they are, to a much lesser extent the
chemosynthetic micro organisms. These are the green plants, higher saprophytes
as well as lower forms, the phytoplankton’s and some photosynthetic bacteria. We
can define Primary productivity as “the rate at which radiant energy is stored by
photosynthetic and chemosynthetic activity of producers.” Primary productivity is
further distinguished as:
Gross primary productivity: Gross Primary Productivity is the rate of storage of
organic matter in plant tissues in excess of the respiratory utilization by plants
during the measurement period. This is, thus, the rate of increases of biomass. In
this way, net primary productivity refers to balance between gross photosynthesis
and respiration and other plant losses as death etc.
(2) Secondary productivity: These are the rates of energy storage at consumers
level. Since consumers only utilize food materials (already produced) in their
respiration, simply covering the food matters to different tissues by an overall
process. The secondary productivity is not divided into ‘gross’ and ‘net’ amount.
(3) Net Productivity: Net productivity refers to the rate of storage of organic matter not
used by the heterotrophs (consumer) i.e. equivalent to net primary production minus
consumption by the heterotrophs during the unit period. It is thus the rate of increase
of biomass of the primary producers, which has been left over by the consumers.
(4) Stability of Ecosystem: The stability of ecosystems refers to the balance between
production and consumption of each element in the ecosystem. In other words,
balance between input and output of energy and normal functioning of different
biogeochemical cycles and stable conditions of equilibrium as under:-
(i) The Equilibrium Model: The equilibrium model states that an ecosystem,
always tends towards stability. As soon as the community of an ecosystem is
disturbed due to external environmental change, it quickly returns to original
state where as.
(ii) The non-equilibrium model: The non-equilibrium model states that an
ecosystem stability is rarely attained because disturbances caused by frequent
external environmental change do not allow to develop ordered state of species
assemblages in an ecosystem.

DECOMPOSERS
In this world all living organisms require a constant supply of nutrients for growth. The
death and decomposition of plants and animals, with release of nutrients constitutes an
essential link in the maintenance of nutrient cycles. When an organism dies, an initial
period of rapid leaching takes place and populations of macromolecules. The dead organism
is disintegrated beyond recognition. Enzymic action breaks down the disintegrating parts of
the litter. Animals invade and either eat the rapidly recolonized by micro- organisms, and
the litter biomass decreases. It becomes simpler in structure and chemical composition.
Process of Decomposition
The process of decomposition involves three interrelated components, viz.
(i) Leaching (ii) Catabolism, (iii) Comminution.
1. Leaching
Leaching is a physical phenomenon operating soon-after litter fall. Soluble matter is
removed from detritus by the action of water. Sometime over 20% of the total nitrogen
content of litter maybe leached off.
2. Catabolism
The process in a plant or animal by which living tissue is changed into waste products.
3. Comminution
Comminution to make small to reduce to power or minute particles. Comminution
means the reduction in particle size of detritus. During the course of feeding, the decomposer
animals community detritus physically. And utilize the energy and nutrients for their own
growth (secondary production). In due course, the decomposers themselves die and contribute
to the detritus.
Function of Decomposition
The two major functions of decomposition within ecosystems are as under:-
(1) The mineralization of essential elements,
(2) The formation of soil organic matter to inorganic form.
The formation of soil organic matter in nature is a slow process. The decomposition of
any piece of plant detritus may take hundreds of years to complete. However, some residues
of decomposition within this period do contribute to the formation of soil organic matter.
Community of Decomposer Organisms
The community of decomposer organisms includes several bacteria, fungi, protests and
invertebrates. The different species in such a community function in an integrated manner.
For example, a fungus decomposes plant litter and is eaten by an animal. Upon death,
bacteria decompose the animal, and protozoa may eat the bacteria.
Fungi and bacteria are the principal organisms that break down organic matter. Certain
protozoa, nematodes, annelids and arthopods strongly influence their functioning (i.e. of
fungi and bacteria) due to their feeling activities. Microarthopod fauna, comprising mainly
of oribatid mites besides other mites and collembolans, are abundant in most forest, grassland
and desert ecosystem.

Most of these micro-arthropods are predominantly fungal-feeders. They can do as under:
(1) They can decompose substrata.
(2) They can decrease substrata’s mass by leaching soluble intercellular components.
(3) They can do so by oxidation.
(4) They can physically cut in into smaller fragments.
Increased mineralization of nitrogen, phosphorus and potassium has been reported to
be mediated by microarhropods in several studies.
In the same way, the interactions of micro-arthropods with soil fungi are also quite
important in nutrient cycling. Studies of this aspect are made in mycorrhizal fungi and
themicro-arthropods which feed upon these fungi:
(1) It is found that Mycorrhizal pump massive amounts of nutrients form detritus and
represent a sizable nutrient reservoir themselves.
(2) The orbited mites and other micro-arthropods feed on myocardial fungi they act like
herbivorous pests, and can alter nutrient relations/cycling in terrestrial ecosystems.
Table 3.1 : Chief Decomposer Organisms
Division/Class Orders Common Names
Eubacteria Myxobacterales Fruiting bacteria
Cytophagales Gliding bacteria
Spirochaetales Spirochaetes
Actinomycetales Actinomycetes
Cyanobacteria Blue green algae
Myxomycota Slime moulds
Mastigomycotina Chytrids, zoosporic fungi, water moulds
Zygomycotina Mucorales Pin moulds
Eutomophjthorales Entomogenous fungi
Zoopagales Nematode-trapping fungi
Ascomycotina (Several) Yeasts, cup fungi, flask fungi
Basidiomycotina (Several) Ruts, smuts, mushrooms,
Toadstools, bracket fungi, Puffballs etc.
Deuteromycotina Imperfect fungi, puffballs, Pycnidial fungi, etc.
Protozoa Ciliates, amoebas, Flagellates, etc.
Rotifera Rotifers
Nematoda Tricladida Flatworms
Metanemertini Ribbonworms
Annelida Earthworms, leeches
Mollusca Pulmonata Slugs, snails Copepods, amphipods,
Isopods, decapods
Arthropods, Diplopoda Millipedes
Arthropods, Chilopods Centipedes
Arthropods, Insects (Several) Termites, beetles, flies, Moths, ants,
grasshoppers, Cockroaches etc.
Arthropods, Arachnida (Several) Scorpions, sun spiders, Mites, spiders


DECOMPOSERS WITH VARYING RELATIONS
Some decomposer organism’s cannot be assigned a rigid or fixed position in the food
web. Their trophic relations can vary from time to time.
1. Nectroph: Some decomposers are nectrophs. They cause rapid death of the food
source because they have a short-term exploitation of living organism. Nectrophs
include may plant parasitic microbes as well as some herbivores, predators, and
microtrophs (organisms which feed on living bacteria and fungi.)
2. Biotrophs: On the other hand biotopes resort to a long-term exploitation of their
living food resource. For example, root-feeding nematodes and aphids, obligate
plant parasites, e.g., and mycorhizae and root nodules, etc.
3. Saprotophs: The apostrophes utilize food already dead, and most of the decomposers
belong to this category.
Decomposers occupying different trophic levels
There are some such organisms causing decompositions as can occupy various trophic
levels under different conditions. For instance the root parasites like Fusarium and
Thizoctonia are necrotrophs, which often show a saprotrophic tendency. In the same way,
the predators (foxes and kites) sometime behave as saprotrophs. Biotrophs sometime act as
necrotrophs or as saprotrophs.
Soul Invertebrates And Termites
There are some soil invertebrates e.g. earthworms and collembolans distribute organic
matter throughout the soil whereas others e.g. termites and ants, concentrate it at localized
sites around or near the royal chamber or in mounds. The following table shows the estimated
activities of major groups of soil animals.
Table 3.2 : Soil Animals’ Activites
Group (m-2) Density R/Q Production Excretory C/N ratio
Respiratory efficiency products
quotient
Protozoa 0.1-x1000 0.31-0.71 0.34-0.40 Urea ammonia 5
Nematodes 3.9-0-6×106 04.41-0.96 0.04-0.13 Urea ammonia 7.5-12
aminoacids
Annelids 0.650 <0.07 Urea
(eartworms)
Molluscs 0-8500 0.82 Ammonia. urea,
Amino acids
Arthropods
Collembola 700-40,00
Ants, termiter 1000-10,000 Uric acid urates

ENERGY-ITS FLOW IN ECOSYSTEMEnergy-DefinedEnergy can be defined as the capacity to do work, whether that work be on a gross scaleas raising mountains and moving air masses over continents, or on a small scale such astransmitting a nerve impulse from one cell to another.Kinds of EnergyThere are two kinds of energy, potential and kinetic. They can be explained as under:-1. Potential Energy
Potential energy is energy at rest. It is capable and available for work.
2. Kinetic Energy
Kinetic energy is due to motion, and results in work. Work that results from the
expenditure of energy can be of two kinds:
(1) It can store energy (as potential energy).
(2) It can order matter without storing energy.
3. Laws of Thermodynamics
The expenditure and storage of energy is described by two laws of thermodynamics:-
(i) Law of conservation of energy: The law of conservation of energy states that
energy is neither created nor destroyed. It may change forms, pass from one place
to another, or act upon matter in various ways. In this process no gain or loss in
total energy occurs. Energy is simply transferred from one form or place to another.
Two Reactions
There may be either of the two reactions:
1. Exothermic Reaction
When wood is burnt the potential energy present in the molecules of wood equals the
kinetic energy released, and heat is evolved to the surroundings. This is an exothermic
reaction.
2. Endothermic Reaction
In an endothermic reaction, energy from the surrounding may be paid into a reaction. For
example, in photosynthesis, the molecules of the products store more energy than the reactants.
The extra energy is acquired from the sunlight yet there is no gain or loss in total energy.
(ii) Law of Decrease in Energy: The second law of thermodynamics states that on
the transformation of from one kind to another, there is an increase in entropy and
a decrease in the amount of useful energy. In this way, when coal in burned in a
boiler to produce steam, some of the energy creates steam that performs work, but
part of the energy is dispersed as heat to the surrounding air.
Three Sources of Energy
Three sources of energy account for all the work of the ecosystem. These sources are
gravitation. Internal forces within the earth and solar radiation. The last one is significant


for ecosystem. The solar radiation, which originates from sun is the source of energy for lifeand is what sets the ecosystem, besides other natural system.Energy FlowDue to unidirectional flow of energy, the behaviour of energy in ecosystem is calledEnergy Flow. From the energetics point of view, energy flow is explained as under:(i) The efficiency of the producers in absorption and conversion of solar energy.(ii) The use of the above said converted chemical form of energy by the consumers.(iii) The total input of energy in form of food and its efficiency of assimilation.
(iv) The loss caused through respiration, heat, excretion etc.
(v) The gross, net production.
Single Channel Energy Model
Lindemann (1942) was the first to propose the community energetics approach or the
trophic-dynamic model) to ecology, which enables an investigator to compare the relative
rates at which different kinds concerning energy flow through forest ecosystems by the
application of this kind of approach, e.g. by comparing ratios of leaf fall to litter deposition
on the forest floor. His conclusion was that the rates of leaf production are higher and those
of litter accumulation lower, in the tropics than at higher latitudes.
Solar radiation
118, 872
Decom position
3.0 Decom position
0.5
Decom position
(trace)
Not utilised
1.2
Respiration
1.8
Not utilised
7.0
Respiration
4.5
Not utilised
70.0
Respiration
23.0
HERB IVO RES
(G .P.)
15.0
CARNIVO RES
(G .P.)
3 .0
AUTO TRO P HS
G ross production
(G .P.)
111.0
 Single channel energy model.
The following conclusion can be drawn from the above figure:
(1) Out of the total incoming solar radiation (118,872 g cal/cm2 /yr), 118,761 gcal/cm2/yr
remain unutilized. In this way, the gross production (net production plus respiration)
by autotrophs comes to be 111 gcal/cm2/yr with an efficiency of energy capture of
0.10 per sent.



<<< Previous                                                             Next >>>