Species diversity

The number of species of plants and animals that are present in a regieon constitues Its species diversity.This diversity is seen both in natural ecosystems and in agricultural ecosystems.some areas are richer in species than others.For example,natural undisturbed tropical ecosystems.some areas are richer in species richness then monoculture plantations developed by the forest Department for timber production .A natural forest ecosysstem provides a large number of non-timber forest products(NTPF's)that local people depand on ,such as fruit ,fuelwood,fooder,fiber,gum ,resin and medicins.Timber plantations do not provide the large variety of goods that are essential for local consumption .In the long-term ,the economic sustainble returns from NTFPs is said to be greater than the returns from felling a forest for its timber.Thus ,the commercial value of a ntural forest ,with all its species richness is much greater than a plantation .Moderen intensive agricultual ecosystem have a relatively lower diversity of crops than treditional agro-pastoral farming systems,where multiple crops were planted.

At present ,conservation scientists have been able to identify and catagerize about 1.8 million species on Earth .However,this this is only a fraction of what really exists .Many new species are being identified especially in the flowering plants and insects.Areas that are exceptionally rich in speicies diversity are called especially'hotspots'of diversity ;India is among the world's 15 nations that are exceptionally rich in species diversity.

Genetic Diversity

Each member of any animal or plant species differs widely from other individuals in its genetic makeup,owing to the large number of combinitions possible in the genes that give every individual specific its charecterstics.Thus,for example,each human being population of a species.If the number of breeding individuals is reduced,the dissimilary of genetic makeup is reduced and in-breeding occurs.This leads to genetic anomalies and eventually ,to the extinction of that particular species .The diversity in wild species forms the'gene pool' from which our crops and domestic animals have been developed over thousands of Years.Today,the variety of natur's bounty is being further expoited by using wild relatives to create new varieties of more productive,disease-resistant crops and to breed superior domestic animals .Modem biotechnology also manipulates genes to develop better types types of medicins and a variety of industrial products.

Definition

'Biological diversity or biodiversity is that part of nature which includes the differences in genes among the individuals of s species;the variety and richness of all the plant and animal species at different scales in space-locally,in a region ,in the country and the world;and the types of ecosystems.both terrestrial and aqutic,within a defined area.
'Biological diversity deals with the degree with the degree of nature's variety in the biosphere.This variety can be observed at three levels-the genetic variability within a community ;and the organization of species in an area in to distinctive plant and animal communities .

Defination

'Biological diversity or biodiversity is that part of nature which includes the differences in genes among the individuals of species;the variety and richness of all the plant and animal species at different scales in space-locally,in a region ,in the country and the world;and the types of ecosystems,both terrestrial and aquatic,with in a defined area.

BIODIVERSITY

The great variety of life on the Earth has provided for man's needs over thousands of years.This diversity of living creaturs forms a support system which has been used by each civilization for its growth and development.Those that used this bounty of nature carefully and sustainably survived ,while those that overused or misused it disintegrated.
Science has attempted to calssify and categorizecthe variability in nature for over a century.This has led to an understanding of its organiztion in to commubities of plants and animals.This information has helped in utilizing the Earth's biological wealth for the benefit of humanity and has been integral to the process of 'devolopment'.This includes better health care ,better crops and the use of these life-forms as raw meterial for industrial growth ,which has led to a higher standard of living for the developed world .However,this has also produced the modern consumerist society ,which adversely affects the disversity of biological resources upon which it is based .The diversity of life on Earth is os great that if we use it sustainbly we can go on devoloping new products from biodiversity for many generations.This can only happen if we manage biodiversity as precious resource and prevent the extinction of species.

Aquatic Ecosystems Using

Man uses aquatic ecosystems for the clean freshwater on which his life completely depedent.we need clean water to drink and for other domestic uses.Water is also essential for agriculture.Fisherfolk use the aquatic ecosytems to earn a livilihood,Pelple catch fush and crabs;they also clooect edible plants .These are used locally as food or for sale in the market .Over -fishing leads to a serios decline in the catch and long-term loss of income for the fisherfolk.

Marshers and wetlands are of great economic importance for people who live on their fish crustaceans ,reeds ,grasses and other produce.

Modern man impounds water in dams to be able to store it throughout the year.Agriculturae and industry are highly dependent on large quantites of water .However this leads to problems for tribal people who have lived there before the dams were built as they are displaced for these dams.

Dams are built across rivers to generate electacity.A large proporation of this energy is used by urban people ,by agriculterists in irrigated farmlands and in enourmous quantities for industry .Large dams have serios ill-effects on the natural river ecosystems .while the water from dams used for irrigation has led to economic prosperity in some areas, in semi-arid areas briught up into the surface layers of the soil.This makes such lands gradually more and saline and unproductive.

Seashore Ecosytems

Beaches can be sandy ,rocky ,shell-coveredor muddy,On each of these different types,there are several specific species which have envolved to occupy a seperate niche.There are different crustanceans,sucha sa crabs,that make holes in the sand,Various shore birds feed on their pry by probing in to the sand or mud on the seashore.Several different species of fish are caught by fishermen.In many areas the fish catch has decreased over the last tow decades.

Marine Ecosystems

The Indian Ocean,the Arabian sea and the Bay of Bengal constitue the marine ecosystems around peninsulat India.In the coastal area,the sea is shallow while further away,it is deep .Both these are different ecosystems.The producers in this ecosystem vary from microscopic algae to latge seaweeds .There are millions of Zooplankton and a large variety if invertebrates which fush ,turtels and marine mammals feed on.

The shallow areas near Kutch and around the Andaman and Nicobar Islands are some of the most increrdible coral reefs in the world .Coral reefs are only second to tropical evergreen forests in their richness of species .Fish,crustaceans,starfish,jellyfish and polyps that deposit the coral are just a few if the thousands of species that form this incredible world under the shallow seas.

The deforestation of the adjacant mangroves leads to silt being carried out to sea where it is deposited on the coral ,which gets bleached and than dies.There are many diffrerent types of coastal ecosystemes which are highly dependent on the tide.

The marine ecosystem is used by coastal fisherfolk for fishing ,which is their livlihood.In the past,fishing was done at sustainable level adn the marine ecosystems continued to maintain its abudant supply of fish over many generations.Now,with the growth of intensive fishing by using gaint nets and mechanized boats,the fish cathc in the Indian Ocean has dropped signifciantly.

Stream and river ecosystems

Streams and rivers are flowing water ecosystems,in which all the living forms are specially adapted to different rates of flow .some plants and animals ,such as snails and other burrowing animals,can withstand the rapid flow of the hill-streams.Other species of ifsh like the Mahseer,go beetles and skaters ,can live only in slower moving water .Some species of plants and animals ,like water upstrean form rivers to hill-streams for bredding.They need crystal-clear water to be able to breed.

As deforestation occurs in the hills,the water in the streams that once flowed throughout the year becomes seasonal .This leads to flash-floods in the rains and a shortage of water once the streams dry up after the monsoon.

The community of flora and fauna of strems and rivers depends on the clarity.Flow and Oxygen content,as well as the nature of their beds.The stream or river can have a sandy,rocky or muddy bed,each type having its own species of plants and animals

More

Graudally ,the more complex animals such as crabs ,frogs and fish return to the pond.The vegetation in the water consists of floating weeds and rooted vegetation on the peiphery whose roots are in the muddy floor under the water and whose foliage emerges out of the surface of the water.
As the pond fills inthe monsson season , a large number of food chains are formed .The algae are eaten by microscopic animals,which are turn eaten by small fush on which the larger carnivorous fish depend .These are in turn eaten by birds of prey.Aquatic insects,worms and snails feed on the waste material excerted by animals and animal matter.They act onthe dertius ,which is broken down into nutrients which aquatic plants can absorb,thus completing the nutrient cyle in the pond .The temporary ponds begin to dry up after the rains and the surrounding grasses and terrestrial plants spread into the moist mud that us exposed.Animals like frogs,snails and worms remain formant in the mud ,awsting the next monsoon.

Ponds Ecosystems

The pond is the simplist aquatic ecosystme to observe

There are differences between a temporary pond that has water only in the monsoon season and a larger tank or lake tht is an aquatic ecosystem throughout the Year.Most ponds become dry after the rains are over and are covered by terrstrial plants for the rest of the Year.

when a pond begins to fill during the rains are over,its life forms -such as the algae and microsopic animals,aquatic insects snails and worms come out of the floor the pond where they have remained dormant during the dry phase.

MORE DEATAILS WILL BE CONTINUE...

Motr

In aqutic ecosystems,plants and animals live in water.These species are adapted to live in different types of aquatic habibates.The special abiotic features are its physical aspects such as the quality of the water ,which includes it s clarity,salinity,Oxygen content and rate of flow .aquatic ecosytems may be classified as being stagnant ecosystems or running water ecosystems.The mud gravel or rocks that form the bed of the aquatic ecosystems are also classified in to freshwater,brackish and marine ecosystems,which are based on the slaianity levels.
The fresh water ecosystems that have running water are streams and rivers.Ponds,tanks and lakes are ecosystems where water does not flow .wetlands are special ecosystems in which the water level fluctures dramtically in different seasons .They have expenses of shallow water with aquatic vegetation,which forms an ideal habitat for fish,crustaceans and water birds.
Marine ecosystems are highly saline,while brajcish areas have less sline water such as in river deltas.Coral reefs are very rich in species and are found in only a few shallow tropical seas .The richest coral reefs in India are around the Andaman and Nicobar Islands and in the Gulf of Kutch .
Brackish water ecosystems in river deltas are covered by mangrove forests and are among the worlds most productive ecosystems in items of biomass production.The largest manganore swamps are in the sunderbans in the delta of the Ganges river

Aquatic Ecosystem

The aquatic Ecosystems comprise of the marine environments of the seas and the fresh water systems in lakes,rivers,ponds and wetlands.These ecosystems provide human beings with a wealth of natural resources.They provide food like fish and crustaceans.Natural aquatic such as rivers and seas,break down the chemical and organic wastes created by man .Hoever,this function has limitations,as the aquatic ecosystem cannot handle grat quantities of waste .Beyond a certain limit ,pollution destroys this natural function.

If aquatic ecosytems are misused or over-uitlized ,thier ability to provide resources suffers in the long teem.over-fishing leads to fall in fish catch .River courses that are changed by dams to provide electricity affect thousands of people who do not get a continuous supply of water downstream for their daily use .when wetlands are drained ,their connected rivers tend to cause floods.wetlands are drained,their connected rivers tend to cause floods .These are all exemples of unsustainable changes in the use of natural resources and nature's ecosystems that are dependent onhydrological regimes.

water is an important factor in all our ecosysms.several ecosystems exist in fresh water and marine saltwater.There is very little fresh water on earth ,which fundamental resource for people all over the world.

Desert Ecosystems

Desert and semi-arid lands are extremely specialized and sensitive ecosystems that are easily destroyed by human activites.The species of these dry areas can live only in this specialized habibat .
The deserts and semi-arid areas are mainly located in western India and the Deccan plateau .The clinate ub these vast tracts is extremely dry.There are also cold deserts such as in Ladakh ,which are located in the high plateaus of the Himalayas.The most typical desert landscape that is seen in Rajasthan is in the Thar Desert.This has sand dunes;it also has areas covered with sparse grasses and a few shrubs,which grow if it rains.In most areas of the Thar,the rain only once every few years .In the adjoining semi-arid tract ,the vegetation consists of a few shrubs abd throny trees,such as kher and babul.
The Great and Little Rann of Kutch are extraordinarily specialized arid ecosystems .In the summers,they are similar to desert landscape.However ,as these are low-lying areas near the sea,they gert converted to salt marshers during the monsoons.During this perios they attract an enomous number of aquatic birds ,such as ducks geese,crans ,strokes,etc..The Great Rann is famous as it is the onle known breeding colony of the Greater and Lessar Flamingous in India.

Grassland species vanishing

Most people feel that it is only our forests and its wildlife that isdisappearing .However,other natural ecosystems,such as grasslands,are disappearing even morerapidly.
Many of the grasslands,are disappeared from several parts of India in which they were found 50 or 60 years ago.The cheetah is extinct in India;the wolf is now highly threatned;the blackbuck and chincara are being poached for thir meat;birds sucha s the beautifull great Indian Bustard and vanishing.unless grassland species are protected,they will vanish form their shrinking habibat ,as natural and undisturbed grasslands are left in very few locations.If these animals and birds are killed or their habibat is reduced further ,their extinction will rapidly follow.

Threats to Grass land

In many areas,grasslands have been used for centuries by pastoral communties.Over utilization and in many changes in landuse of the 'common grazing lands' of rural communities has lead to their degradation c.The grassland cover in the country,in terms of permanent pastures,nw covers only 3.7% of the total land.A main threat to natural grasslands is the conversation of grasslands into irrigated farmlands .In the Deccan,grasslands have been altered to irrigated farms and are now mainly used to grow sugercane,which is a water-intensive crop.After continuous irrigation ,such land becomes salineuseless in a few years .More recently,many of these residual grasslands tracts have been converted in to industrial areas.This provides short-term economic gains but results in longterm economic and ecological losses.
Grasslands have a limited ability to support domestic animals and wildlife.Increasing this pressuring by increasing the number of domestic animals reduces the'naturalness' of the grassland ecosystem leading to its deterioration.
Most grassland ecosystem are highly modified by human activities .Cattle,sheep and goat grazing and lighting repeated fires all affect the grass lands adversely.changing the grasslands to other forms of landuse such as agriculture,tree plantations and industrialization poses a serious threat to this highly-productive ecosystem.Thus some of the grassland patches,which are in a less disturbed state and have retained their special plants and animals ,need tobe urgently protected.
The degradation of grasslands due to over-grazing by scttle,sheep and goats occures if more than a critical number of doemstic animals are presemt in the grasslands.when animals overgrgraze the area,the grasses are converted into flat stubs with very little green matter .Degraded grasslands have fewer grass species as the nutrious species are entirely used up by the large number of domestic animals and are thus unable to regenerate.

Grasslands uses

Grasslands are the grazing areas of many rural communities.Farmers who keep cattle or goats ,as well as shpherds who keep sheep are highly dependent on grasslands .Domestic animals are grazed in the 'common' land of the village.Fooder is collected and stored to feed cattle when there is no grass left for them to graze in summer.Grass is also used and farm-sheds.The thorny bushes and branches of the few trees that are seen in grasslands are used as a major source of fuelwood .
over-grazing by huge herds of domestic llivestock has degreaded many grasslands.Grasslands have diverse species of insects that pollinate crops.There are also predators of these insects such as the small mammals like srews,reptiles like lizaeds,birds of prey and ambhibians such as frogs and toads .All these carnivorous animals help to control insect pests in the adjoining agricultural lands.

Shola Grasslands

Grasslands are not restricted only to low rainfall areas .Certain grassland types form when clearings are made in different forest types.Some are located on the higher,steep hill-slopes with patches of forest that occur along the streams and in depressions.The grasslands are related to repeated fires that do not permit the forest to grow.

The grasses are the major producers of biomass inthese regions .Each grasslland ecosystem has a excessive grazing and are suppressed if the area is over-grazed.Others are destroyed by repeated fires and cannot regenerate.Thus over-used or frequently burnt grasslands are degraded and are poor in plant species diversity.

The Terai consists

The terai consists of patches of tall grasslands interpresed with a sal forest ecosystem.The patches of tall elephant grass,which frow to a height of about five meters,are located in the low-lying water logged areas.The sal forest patches cover the elevated regions and the Himalayan foot hills . The terai also includes marshes in low-lying depressions.This ecosystem extends in a belt south of Himalayn foothills.
The semi-arid plains of westren India,Central India and the Deccan are covered by grasslands.tracts withpatches of thron forest.Several mammals susch as the wolf,the blackbuck,the chinkara,and birds such as the bustards and floriccans,are adapted to these ard conditions .The scrublands of the Deccan plateau are covered with seasonal grasses and herbs on which its fauna is dependent.It teems with insect life on which the insectivorous birds feed .
The shola grasslands consist of patches on hill-slopes that occur alongside the shola forests on the westren Ghats,the Nilgiri and Annamalai ranges.These form patchworks of grassland on the slopes and forest habibats along the streams and low-lying areas.

Types of Grasslands in India

Grasslands form a variety of ecosystems that are located indifferent climate conditions ranging from near-desert conditions,to patches of shola grasslands that occur on hill-slopes alongside the exteremly moist evergreen forests in South India.In Himalayan mountains there are the high cold Himalayan pastures.There are tracts of tall elephant grass in the low-lying terai belt south of the Himalayan foothills.There are also semi-arid grasslands in Western India ,parts of central India,and inthe Deccan plateau.

The Himalyan pasture belt extends up to the snowline;the grasslands at a lower level form patches along with requires both the forest and the grassland ecosystem as important parts of their habibat.The animals migrate up in to the high-altitude grasslands in the summer and move down in to the forest in the winter when the snow covers the grasslands .These Himalayan pastures have a large variety of grasses and herbs.These Himalayan hi;;-slopes are covered with thousands of colorful flowering plants as well as a large number of medicinal plants.

Grassland Ecosystems

A wide range of landscaoes,in which the vegetation is predominantly grasses and small annual plants are specifically adapted to India's various climate conditions.These form a variety of grass land ecosystems with their specific plants and animals.

Grassland cover areas where rainfall is usually low and/or the soil depth and quality is poor,The low rainfall prevents the growth of large number of trees and shrubs ,But is sufficiant to support the growth of grass cover during the monsoon .Many of the grasses and other small herbs become dry and the part above the ground dies during the summer months.In the next monsoon the grass cover grows back from yhe root-stock and the seeds of the previous year .This change gives grass lands a highly seasonal appearence,with periods of increasd growth being followed by a dormant phase.

Forest services

Forest Services include the control of the flow of water in streams and rivers .Forest cover reduces the surface run-off of rainwater and allows ground water to be stored.Forests also prevent the erosin of soil.Once soil is lost by erison ,it can take thousands of years to re-form.Forests also regulate the local temperature .It is cooler and moister under the shade of the trees in forest .Most importantly forests absorb carbon dioxide and release the oxygen that we breath.
The wild relatives of our crop plants and fruit trees have special characterestics in their ganes,whicha are used to develop new crops and newer varieties of fruit.These newer varieties ,developed form wild relatives,give greater yields or are more resiistant to diseases .New industrial products are being produced from the wild plants of the forest .Many of our new medicins come from wild plants

Forest Products

Forest products that are collected by people include food like fruit,roots,herbs and medicinal plants.People depend on fluewood to cook food,collect fodder for domestic animals and cut building meterial for housing;collect medicinal plants that have been known for generations to treat several aliments;and use a variety of NTFPs such as fiber,cane and gum,to make house hold articles,Woods from different species of trees are put to a variety of uses for the yoke of a bullock cart while hardwood is used for its axle.
These forest products are of gteat economic value as they are collected,sold and marketed .Forest dwellers and agricultural oeioke use these goods directly,while other people get them indirectly from the market treditional types of agriculture need forest meterial like branches and wood-ash which acts as a fertilizer for crops such as rice.Urban people use these forest resources indirectly as all their food and other goods come from agricultural areas that are dependent on the neibouring forests.

In Monsson

During monsoon ,the forest retains moisture and slowly releases it through peronnal streams during the rest of the year.Plantations fail to perform this function adequately.The loss of forest cover in the catchments of a river thus leads to irreversible changes ,such as excessive soil,erison,large run -off of surface water during monsoons leading to flash-foods,and a shortage of water once the monsoons are over.

Forest Utilization

Natural forests provide local people with a vareity of products,if the forest is used carefully .Over exploitation for fuelwood or timber,and conversion to monoculture plantation for timber or other products,impovereshies the local people as the economic benifit useually accures to people who live elsewhere .The entire resource base ,on which local people have traditionally survived generations ,is rapidly destroyed .Eventually ,the forest is completely degrated .
Natural forest Ecosystems play an important role in controlling local climate and water regimes .It is a well-known fact that it is cooler under the canopy of a natural forest than it is cooler than outside the forest .

Forest communities

=====================================================================
Forest type plants Esamples common Animal Example Rare Animal Examples
=====================================================================
Himalayan coni- pine,deodar wild goats and sheep, snow lwopard,Hangul,
ferious Himalayn black bear Himalayan brown bear
Himalayan Broad Maple, Oak
leaved
Evergreen North- Jamun,ficus Tiger,Leopard,sambar, pigmy hog,rhino
east,westren Ghats, Dipterocarpus Malabar,whistling thrush, Lion-tailedmaca
Malabarpiedhornbill,Treefrofs que
Deciduous Mosit Sal
Throan and scrub,
semi-arid forests Babul,ber,neem Black buck,chinkaa,Four-hormed Bustardflorician
antelope,partidge,Montior lizard
Mangrove Delta Avicenia Crocodiles,shorebirds-
Forests sandpipers,plovers,fish custanceans

Thorn Forests

Thorn forests are found in the semi-arid regions of India.The trees,which are sparsely distributed,are surrounded byopem grassy area.Throny plants,called xerophytic species are,able to conserve water,some of these trees have small leaves ,while other species have thick ,waxy leaves to reduce water losses during transpiration.Thron-forest trees have long or fibrous roots to enable them reach water at great depths.Many of these plants have throns,which reduce water loss and protect them from herbivores.
Mangrove forests grow along the coast especiallly in the river deltas.These plabts are uniquely adapted to be able to grow in amix of saline and fresh water.They grow luxuriantly in muddy areas covered with silt that the rivers have brought down.The mangrove trees have breathing roots that emerge form mudbanks.

Decidous forests

Decidous forests are found in regions with a moderate amount of seasonal rainfall that lass for only a few months .Most of the forests in which Teak trees grow are of this type .The dediousous trees shed their leaves during the winter and hot summer months .In march or April they regain their fresh leaves just before the monsoon ,when they gtow vigorously in response to the rains.Thus,there are periods of leaf-fall and cancopy regrowth .The forest frequently has a thick undergrowth as light can penerate easily on to the forest floor.

Broad-leaves

Forests are of several types of evergreen forests,decidous forests .Broad leaved trees useually have large leaves of various shapes and are found in middle to lower latitudes.

Evergreen forests grow in the high rainfall areas of the western Ghats .North ,eastren India and the Andaman and Nicobar Islands .These forests gow in areas where the monsoon period lasts for several months.Some places even get two monsoons,such as in southern India .Evergreen plants shed a few of their leves throughout the year.Ther is no dry leafless phase as in the case of decidouous forests .So,an evergreen forest looks green throughput the year.The trees overlap with each other to form a continuous canopy.Thus,very little light penetrates down to the forest floor.Only a few shade-loving plants can grow in the ground layer in areas where some light filters down from the in areas where some light filters down from the closed canopy.The forest is rich in orchids and ferns.The barks of the trees are covered in moss .The forest abounds in animal life and is very rich in insect life.

Forest types

Forest types in India
The forest type depends upon the abiotic factors such as climate and soil characteristics of a region.Forests in India can be broadly devided in to coniferous forests and broad-leaved forests.They can also be classified according to the nature of their tree species-evergreen,decidous,xerophytes or thron trees,mangroves,etc.They can also be classified according to the most abundant species of trees,such as sal or teak forests.In many cases,a forest is named after the first three or four most abundant tree species.
Coniferous forests grow in the Himalayan mountain region ,where the temperature are low.These forests have tall stately trees with neddle-like leaves and down ward-sloping branches,so that the snow can slip instead of seeds and are called gymnosperms.

The biotic component

The biotic component includes both the large(macrophytes)and the microscopic plants and animals.plants include the trees,shrubs,climbers,grasses,and herbs in the forest.These include species that flower(angiosperms), and non-flowering species(gymnosperms)such as ferns,bryophytes,fungi and large .
The animals include species of mammals ,birds,reptiles,amphians,fish,insects and other invertebrates and a veriety of microscopic animals. As the plant and animal speices are closely dependent on each other ,together they form different types of forest for several natural resources that act as their life-support systems.people who do not live in the forest produce indirectly from the market.

Forest ecosystems

Forests are formed by a community of plants,which is predominatlystructurally defined by its trees,shrubs,climbers and ground cover .Natural vegestation looks and is vastly different from a group of planted trees in orderly rows.The most'natural'undisturbed forests are located mainly in our national parks and wildlife sanctuaries.The landscapes that make up various types of forests look very different from each other .Their distinctive appearence are fascinating aspects of nature.each forest type forms a habibat for a specific community of animals that are adapated to live in it.

The non-living or boiticaspects of the forest: The type of forest depends upon the abiotic conditions at the site.The forest on mountains and hills differ from those along river valleys .The vegetation is specific to the amount of rainfall and the local temperature ,which vary according to latitude and soil type.

The living or the biotic aspects of the forest:The plants and animals form communities that are specific to each forest type.For instance ,confierous trees occir in the Himalayas;mangrove trees occur in river deltas;thron trees grow arid areas.The snow leopard lives in himalyas while the leopard tiger live in the forests in the rest of India.wild sheep and goats live high up in the himlayas ,and many of the birds of the Himalayan forests are different from those in the rest of India.The evergreen forests of the westren Ghats and North-east India have the richest diersity of plant and animal species.

The ecological pyramids

In an ecosystem,green plants ,the producers,utilize energy directly from sunlight and convert it into matter.A large number of these organisms form the most basic or first'trophic level ' of the food pyramid .The herbivores that eat plants are at the second tropphic level and the called primary consumers.The predators that feed on them form the third trophic level consisting of the carnivores at the apex of the food pyramid .This how energy is used by living creatures and flows through the ecosystem from its base to the apex.

The food webs

In an ecosystem there are a very large number of interlinked chains;together,these form a food web .if the links in the chains that make up the web of life are disrupted due to human activities that lead to the loss or extinction of species,the web break down.

The Food Chains

The most obivious aspect of nature is that energy must pass from one living organism to another.when herbivorous animals feed on plants energy is transffered from the plants of the animals .In an ecosystem ,some of the animals feed on other living organisms ,while some feed on dead 'detrius' food chain.At each link in the chain a large part of the energy from the food chain .At each link in the chain a large part of the energy from the food is lost through daily activities .Each chain useually has only activities .Each chain useually has only four to five such links.However , a single species may be linked to a large number of species.

FOOD CHAINS AND FOOD WEBS etc..

The transfer of energy from the source in plants through a series of organisms,by eating and being eaten ,constitutes food chains.At each transfer, a large proporationof energy is lost in the form of heat .These food chains are not isolated sequences,but are interconnected with each other.This interlocking pattern is known as the food web .Each step of the food web is calle da trophic level .These trophic form the ecological pyramid.

Ecological succesion

Ecological succesion is a process through which ecosystems tend to change over a period of time succession can be related to seasonal environmentla changes,which create changes in the community of plants and animals living in the ecosystem .Other successional events may take much longer periods of time,extending to several decades.If a forest is cleared ,it is intially colonized by a certain group of species of plants and animals ,which gradually change through an orderly process of community development.One can predict that a cleared or open area will gradually be converted in to grassland ,a shrubland ,and finally a woodland and a forest ,if permitted to do so without human intergerence.There is a tendency for succession to produce a more or less stable state at the end of the successional stages.Developmental stages in the ecosystem thus consist of a poineer stage,a series of changes known as serial stages,and finally a climax stage.The succesive stages are rtelated to the way in which energy flows through the biological system.The most frequent example of successional changes occur in pond ecosystems,where it fluctuates from a dry terrestrial habibat to the early colonization stage by small aquatic speces after the monsoon,which gradually passes through to a mature aquatic ecosystem,and then reverts back to its dry stage in summer when its aquatic life remains dormant.

INTEGRATION OF CYLES IN NATURE

These cycles are part of global life processses.These biogeochemical cycles have specific features in each of the ecosystems.These cycles are linked to those of adjacant systms,althrough their characteristics are specific to the plant and animal communities in the region .This is,in turrn,related to the geographical features of the area,the climate and the chemical composition of th esoil.To gether,the cyles are responsible for maintaing life on Earth.If mankind distrurbs these cycles beyond the limits that nature can sustain,they will eventually break down and lead to degrated Earth on which man will not be able to survive.

THE ENERGY CYCLE

The energy cycle is based on the flow of enrgy through the ecosystem.The energy from sunlight in converted by the plants themselves into growing new plant meterial,which include the leaves ,flowers fruit,branchesmtrunks and roots of plants .Since plants can grow by converting the sun's energy direcly in to their tissues ,they are known as producers in the ecosystem.The plants are used by herbivores as food which givs them energy .A large part of this energy is used up for the metabolilc functions of these animals such as breathing ,digesting food,supporting growth of tissues,maintaining blood flow and body temperature .Enaergy is also used for finding shelter ,breeding andrearing the young ones.The carnivores ,In turn,depend on the herbivores,on which they feed.Thus different plant and animal species are linked to one another through manydifferent linkages,these interlinked chains can be depicted as a complex food web.This is thus called the 'web of life' that shows that there are thousands of interrelationships in nature.
The enrgy in the ecosystem can be depicted in the form of food pyramid or energy pyramid.The food pyramid has a large base of plants called producers.The pyramd has narrower middle section that depicts the number and biomass of herbivores animals,which are called 'first orderconsumers',The apex depicts the small biomass of carnivores animals called 'second-order consumers'.Man is one of the anumals at the apex of the pyramid.Thus,to support mankind,there must be large base of herbivorous animals and an even greater quantity of plant meterial.
When plants and animals die,this meterial is returned to the soil after being broken down in to simpler substance by decompossers such as insects,worms,bacteria and fungi,so that plants can absorb the nutrients through their roots.Animals excerte waste products agter digesting food ,which goes back to soil.This links the energy cyle to the nitrogen cycle.

The nitrogen cycle

carnivores fed on herbivores that in turn ,feed on plants.when animals defecate,this waste meterial is broken down b worms and insects,mostly beetles and ants.These small'soil animals'break the waste meterial in to smller bits on which microscopic bacteria and fungi which microscopic bacteria and fungi can act.This meterial is thus broken down further in to nutrients that plants can absorb and use for their growth .In this manner,nutrients are recycled back from animals to plants.similarly,the bodies of dead animals are also broken down in to nutrients that are used by the plabts fir their growth.Thus,the nitrogen cycle on which life is dependent is completed.
The nitrogen fixing bacteria and fungi in the soil give this important element to plants,which absorb it as nitrates.These nitrates are a part of the plant's metabolism,which help in forming new plant proties.This is used by the animals that feed on the plant .The notrogen is then transferred to be the carnivores when they feed on the harbivores.so ,our own lives are closely interlinked to soil animals fungi and even the bacteria in the soil .when we think of food webs,we useually think of the large mammals and other large forms of life.But we need to understand that it is the unseen small animals , plants and microscopic forms of life that are of great value for th efunctioning of the ecosystem .

The carbon cycle

The cabon found in organic compounds is included in both the abiotic abd biotic parts of the ecosystem.carbon is a building block of both plant and naimal tissues.In the atmosphere ,carbon occurs as carbon dioxide.In th epresence of sunlight ,plants take up carbon dioxide from the atmosphere through their leaves.The plants combine carbon dioxide with water ,which is absorbed by their roots from the soil .In the presence of sunlight they are able to form carbohydrates that contain carbon .This process plants releases oxygen in to the atmosphere on which animals depend for their respiration ,thus plants help in regulating and monitoring the percentage of oxygen and carbon dioxide in the Earth's atmosphere.All of manking depends on the Oxygen generated through this cyle.IT also keeps tje co2 at a cceptable levels.

The water cycle

when it rains,the water runs along the ground and flows into rivers or fallsdirectly in to the sea .A part of the rainwater that falls om land percolates in to the ground.This is stored underground throughout the rest of the year.Water is drawn up from the ground by plants along with the nutrients from the leaves as water vapor and returned to the atmosphere .As it is lighter than air,water vapor rises and forms clouds.The winds blow the clouds for long distances and when the clouds rise higher,the vapor condences and changes into droplets,which fall on the land as rain .Although thus is an endless cycle on which life depends ,man's activities are making drastic changes in the atmosphere through pollution which is altering rainfall patterns.This had led to prolonged drought periods extending over years in countries such as Africa,while causing over years in coutriessuch as Africa ,while causing devastating floods in countries such as the UA.The ELNino stroms due to these egffects have ranged many places in the last few years.

Energy flow in the ecosystem

Every ecosystem has several interrelated machinisms that affect human life.These are the water cycle, ,the carbon cylce,the oxygen cycle,the nitrogen cyle and the energy cyle and the energy cycel.while every ecosystem is controlled by these cycles,eachecosystem's abiotic and biotic features are distinct form each other.All the functions of the ecosystem are in some way related to the growth and regeneration of its plant and animal species.These interllinked process can be depicted as the various cycles;all these processes depand on energy from sunlight.During photosynthesis,cabon dioxide is absorved by plants and oxygen is released in to hte atmospher.Animals depend on this oxygen for their resprition.The water cycles depends on the rainfall,which is necessary for plants and Animals to live .The energy cycle recyles nutrients in to the soil on which plant life grows.Our own lives are closely linked to the proper functioning of these cycles of life.If human activities go on altering them .humanity cannot survie on Earth.

Decomposers

Decomposers or detrivores are a group of organisms consisitng of small animals like worms ,insects,bacteria and funfi,which break down dead organic meterial in to smller particles and finally in to simplet substances that are used by plants us nutrition.Thus,decomposition is a vital function in nature,as without this,all the nutrients would be tied up in dead matter and no new life would be produced.
Most ecosystems are highly complex and consist of an extremely large number of individuals of a wide variety of species .In the species-rich tropical ecosystems(such as in our country),only a few species are very common, while most species have relatively few individuals .some species of plants and animals are extremely rare and may occur only at a few locations .These are said to be 'endemic'to these areas.
when human activities alter the balance in these ecosystems,such pertubations often lead to the disappearence of some uncommon species when this happens to an enademic species that is not widly distributed ,it beocnmes extinct forever.

levels

Every living organsim is in some way dependent on other organisms.plants are food for herbiorous animals ,which are in turn food for carnivorous animala.Thus ,there are different tropic levels in the ecosystem.some organisms such as fungi live only on dead meterial and inorganic matter.

Plants are the'producers'in the ecosystem,as they manufacture their food by using energy form the sun.In the forest these form communities of plant life .In the sea seaweed.

The herbivrous animals are 'primary consumers 'as they live on the producers.In a forest,these are the insects,amiphians ,reptiles,birds and mammals .The hebivorous animals include,for example ,the hare,deer and elephants that live on plant life .They graze on grass or feed on the foliage from trees.In grasslands,there are grassland,there are herbivavores such asblackbuck that feed on grass.In the semi-arid areas,there are species sucha s the chinkara or indian gazelle.In the sea,there are small fish that live on algee and other plants.

At a higher tropic level,there are carnivorous animals or 'secondary consumers which live on the herbivores.In our forests the carnivores are tigers,lwopards,jackals,foxes and wilds cars.In the sea,carnivarous fish live on other fish and marine animals.The animals that live in the sea range in size froms to gaint mammals such as the whale.

FUNCTIONS OF ECOSYSTEM

Structure and functions of an ecosystem
-------------------------------------------------
Since each ecosysem has a non-living and a living part that are linked to each other ,one needs to look around us and obsereve this closely.Thenon-living components of an ecosystem are the amount of water,inorganic substances and organic compounds,and climatic comnditions,which depend on geographical conditions and organic compunds,and in an ecosystem are inseparable from their habibat.
The living component of plant life ranges from extremely small bacteria.which range from extremely small bacteria,which live in the air,water and soil,algae which live in fresh and saltwater,to the terrestrial plants which range from grasses and herbs that grow after the moonsoon every year ,to the gaint long-lived trees of the forest.The plants convert energy from sunlight in to organic matter for their growth,thus functioning as producers in the systems.The living componenet of the animal world ranges from microscopic animals .to small insects and the large animals such as fish ,amphibians,reptiles,birds and minerals.Man is just one of the 1.8 million species of plants and animals that inhabit the Earth.

Resource Utilization

Most of the traditional societies used their environment fairly sustainably.Though inequality in resource utilization has existedin every society,the number of individuals that used a large proportion of resources was extremely limited .In recent times,the proportion of'rich'people in affluent societies,have grown rapidly.Inequality has thus become a serious problem .whereas in the past many resources such as timber and fuelwood from the forest were extracted sustainably,this pattern has drastically changed during the last century.The economically-powerful sections began to use greater amounts of forest products ,while those people who lived in the forest become increasingly poor.Similarly,the builidng of large irrigation projects has led to wealth in those areas that had canals ,while those who remained dependent on a constant supply of water from the river itself,have found it difficult ti survive.The key to this issue is the need for an 'equitable'disribution of all types of natural resources .A more even sharing of resources with in the community can reduce these pressures on the natural ecosystems.

Ecosystem Degradation

Ecosystems are the basis of life itself!The natural ecosystems in the wilderness provide a variety of products and are regions in which a number of vital ecological processes are present ;without these processes,human civilization would not be able to exist.However,ecosystems are frequently distupted by human actions ,leading to the extinction of spices of plants and animal that can live only in the different natural ecosystem s.some speices ,ifeliminated seriously affect the ecosystem .These are called'Keystone species.Extinction occures due to changes in landuse.Forests are deforested for timber,wetlands are drained to create more agriculture land and semi-arid grass alnd that are used as pastures are converted to irrigated fields.The pollution several species.
The reason for the deplentation of natural is tow-fold-or rapidly exploding population needs increasing resources to sustain to sustain itself,and the growth of affluemt societies that consume
and waste a veru large proporation fo resources and energy.The increasing extraction of resources is at the cost of our natural ecosystems ,leading to a derailing of their important functions.we all use a variety of resources in our daily lives .If traced back to their source,we find that the resources were originally obtained from nature can no longer sustain .If we think before wasting resources such as water,reusing and recycling paper,using less plastic that are non-degradable,all this can cumlatively conserve our natural resources.

Landon Earth

Land on Earth is as any our other natural resources .While mankind has learnt to daapt his lifestyle to various ecosystems world over,he cannot live comfortably for instance on polar ice caps.under the sea,or in space in the foressable future.
Man needs land for building homes ,cultivating food,maintaing pastures for domestic animals,devoloping industries to provide goods and supporting the industries by creating towns and cities,Equally importantly,man needs to protect wilderness are in forests,grasslands,wetlands,mountains,coasts etc..to protect variable biodiversity.
Thus, a rationa; use of land needs careful planning.One can develop most of these different types of land uses almost anywhere ,but protected areas(National parks and wildlife santuries )can only be situted where some of the natural ecosystems are still undistrubed .These PAs are important aspects of good landuse planning.

Land Resources

Landforms like hills,valleys, plains,river basins and wetlands include different resource-generating areas that the people living in them depend on.Many traditional farmung societies from which they used resources.For example in the 'scared groves' of the western Ghats ,requests to the spirit of the grove for permission to cut a tree, or extract a resources were accompained by simple rituals.The outcome of a chance fall on one sideor the other of a stone balanced on a rock gace or withheld permission .The request could not be repeated for a specified period.
if land is utilized carefully ,it can be considered an renewwable resource.The roots of trees and grasses bind the soil.if forests are depleted or grasslands overgrazed ,the ladn becomes unproductive and wasteland is formed.Intensice irrigation leads to water-logged and salinized soil,on which crops cannot grow.

More

In nergy -efficient architecture,the sun,water and wind are used to heat abuilding when the weather is cold and to cool it in summet.This is mostly based on design and building meterial.Thick walls of stone or mud were used in traditonal architecture as an insulator.small doors and windows kept direct sunlight and heatout .Deeply-set glass windows in colonial homes ,on which direct sunlight could not reach ,permitted the use of glass with out creating a greenhouse effect;verandahs also served a similar purpose.Traditional bungalowsalso had high roofs and venitilators that permittedhot air to rise and leave the room .Cross-ventilationhwere wind can drive the air in and out of a room keeps it cool .

Solar Energy

In one hour ,the sun pours as much energy on to the Earth as we use in whole year..Is it were possible to harness this colossal quantum of enefy .Today we have developed several methods of collecting this energy for heaing water,and generating electracity.
Solar heating for homes:Modern houses that use air conditioningand /or heatingare exremely energy dependent.A passive solar home or building is designed to collect the sun's heat through large,south facing glass windows.In solar-heated buildings ,sunspaces are built on the southside of tje structuring and act as large heat absorbers.The floors of sunspaces are useually made of tiles or bricks thatabsorb heat throughout the day,then release heat at night when it is cooler.

Renewable Energy

Renewable energy systms are resources that are constantly replaced and are useually less polluting.Some examples are;Hydro power,solar,wind,and geothermal(energy from th eheat inside the Earth)we also get renewbale energy form burnung trees and even garbage as fuel and processing other plants in to biofuels .

COAL

Coal and its environmental impacts:coal is the world's single largest contributor of green house gases and is one of the most important causes of global warming.
Many coal-based power genetation plants are not fitted with devices such as electrostatic precipitators to reduce emmissions of suspended particulate matter (SPM),which us a major air pollute water vapot,lead to 'acid rain'.This kills forest vegetation,damges archtictural heritage sites,pollutes water and effects human health.
Thermal power stations that use coal produce waste in the form of'fly-ash'.Large dumps are required to dispose of this waste meterial;some efforts have been made to use it for making bricks.The transport of large quantities of fly-ash and its eventual dumping are costs that have to be included in caluclating the cost benefits of thermal power.

OIL AND IMPACTS

Oil and its environmental impacts this is India's oil reserves,which are being used at present,lie off the coast of Mumbai and in Assam.Most of our natural gas is linked to oil and because there is no distribution system ,it is just burnt off.This wastes nearly 40% of available gas.The processes oil and natural gas drilling,processing transport and utilization have serious environmental consequences ,such as leaks in which air and water are polluted and accidental fires that may go on burning for days or weeks they are put out.while refening oil,solid waste like salts and grease are produced,which also oilwells,the cleaning of oil slicks are caused at sea form off shore oil wells,the cleaning of oil tankers and shipwrecks.The most well-known disaster occured when the huge oil-carrier ,the Exxon Valdez snak in 1989 and birds,sea otters,seals fish and other marine life along the coast of Alaska was seriously affected.

Types of Energy

There are three main types of energy:those classified as non-renwble ;those that are said to be renwable;and nuclear energy,which uses such small quantities of raw meterial several of the renewable sources,if not used 'sustainably',can be depleated more quickly than they can be renewed.
Non-renewable Energy
To produce electricity form non-renemable resources,the material must first be ignitied .The fuel is placed in a secured area and set on fire.The heat thus generated turns water to stream ,which noves through pipes,to turn the blaes of a turbine.This converts magnetism electacity ,which we use in various appliances.
Non-renewable Energy sources:These consist of the mineral-based hydrocarbon fuels -coal,oil and natural gas-that were formed form ancient prehistoric forests.These are called 'fossil fuels'because they are formed agter the plant life is fossilized.At the present rate of extraction ,there is enough coal for a long time to come.oil and gas resources.However,are likely to be used up wiht in the next 50 years.When these fuels are burnt,they produce waste products that are released in to the atmosphere as gases such as carbon monoxiode -all causes of air pollution.These have to led to respiratory tract problems in an enormous numberof people all over the world,have also affected historic monuments like TajMahal,and killed many forests and lakes due to acid rain.Many of these gases also act like a greenhouse,letting sunlight in and trapping the heat inside.This is leading to global warming,a raise in global temparatur,increased drought in some areas,floods in other regions,the melting of icecaps,and a rise in sea levels ,which is slowly submering coastal belts all over the world.The warming of the seas also leads to the death of sensitive organisms like coral.

Growing energy needs

Energy has always been closely linked to mans economic gowth ,have used enegy utilization as an index of economic development,focused on rapid economic growth have usd energy utilization as an index of economic development ,.This index howver does not take in to account the advantage long-term effects of excessive energy utilization on society.

More

At present,almost 2 billion people worldwide have no access to electracity at all.While more people will require electrical energy,those who di have no access to it continue to increase their individual as well as at the user level.It is broadly accepted that long-term trends in energy use should be towards a cleaner global energy system that is less carbon intensive and less reliant on finite non and non renewable energy sources .It is estimated that the currently used methods of using renewable energy and non-renewable fossil fuel sources together will be insufficent to meet foreseeable global demands for power generation beyond the next 50-100 years.
Thus,when we use energy wastefully,we are contributing to the environmental deteriaration of our planet.We all need to become responsible energy users.Remember that even a single electrical light that is burning unnecessarily is contributor to environmetal degradation!

sun power

we use enegy for household use,agriculture ,production of industrial goods and for running transport .Modem agriculture uses energy during their maniufacture.The indusry uses energy to power manufacturing units and the urban complexes that support it.Energy-demanding roads and railway lines are built to transport products form place to place and to reach raw meterials in mines and forests.

No energy-related technology is completely 'risk free'and unlimited demands on energy increase this risk factor many -fold .All energy use creates heat and contributes to atmosperic temperature.In addition,many forms of energy release carbon dioxide and lead to global warming .Nuclear energy family plants have caused enormous losses to the environment due to the leakage of nuclear meterial .The inability to effectively manage and safely dispose of nuclear waste is serious global warm

Energy resources

Energy is defined by Physics as the capacity to do work.Energy is found on our planer in a variety of forms,some of which are immediatley useful,while others require a process of trajsformation.

Thesun is the primary energy source in our lives.we use it directly for its warmth and through various natural processes that provide us with food,water,fuel,and shelter.The sun's rays power the growth of plants,which form our food meterial ,give off oxygen which we breathe in and take up carbon dioxide that we breathe out.The sun's energy eveporates water form oceans,rivers and lakes,to form clouds that turn into raon.Today's foosil fuels were once the forests that grw in prehistoric times due to the energy of ht esun.

The chemical energy present in chemical compounds is released when they are broken down by animals in the presence of oxygen .In India,manueal labour is still extensively used to pull carts and ploughs.Electical energy is produced in several ways-power transport,artificial lighting ,agriculture and industry.This comes form hydel power based on the water cycel that is powered by stations powere by fossil fuels.Nuclear energy is held in the nucleus of an atom and is now harnessed to develop electrical energy

More

Scientists now believe that the world will soon need a second green revolution to meet our future demands of food,based on a new ethic of land and water management tha must incorporate values which include environmental sensitivity,equity,biodiversity conservation of cultivars and in-situ preservation of wild relatives of cropp plants.This must not only provide food for all,but also work out a more equitable distribution of both food and water,reduce agricultural dependence on the use of fertilizers and pesticides (which have long-term ill-effects on human welbeing)nad provide an increasing support for preserving wild relatives of crop plants in protected areas.The pollution of water sources,land degradation and desertification mu8st be rapidly reserved.Adopting soil conservation measures,using appropriate farming techniques especially on hill-slopes,enhancing the soil with organic matter ,rotating crops and managing watersheds at the micro level are the keys to agricutural production to meet future needs.Most importantly,food supply is closely linked to the effectivness of population control programs worldwide .The world needs better and more sustainable methods of food production ,which as an important aspect of landuse managements.

Loss of genetic diversity

There are 50,000 known edible plants documented world wide .Of these,only 15 varieities produce 90% of the world's food.Modern agricultural practices have resulted in a serious loss of gentic variability of crops .India's distinctive treditional varieties of rice alone are said to have numbered between 30 and 50,000.
Most of these have been lost to the farmer during the last few decades,as multinational seed companies aggressively push a few commercial genotypes.This Creates a risk to our food security,as farmers can lose all their produce due to rapidly spreading disease.On the other hand,a cereal that has multiple varieties growing in different locations does not permit the rapid spread of a disease.
The most effective method to introduced describle traits in to crops is by using characterstics found in the wild relatives of crop plants.As the widerness shrinks ,these varieties are rapidly disappeaing, once they are completely lost,their desirable characteristics cannot be introduced when found necessery in the future.Ensuring long-term food security may depend on conserving the wild relatives of crop plants in national parks and wild life sanctuaries.
In plant gentic losses world wide are not slowed down,some estimates show that as many as 60,000 plant spices,which accounts for 25% of the world's total ,will be lost by the 2025.The most economical way to prevent this is by expending the network and coverage of our protected Areas.Collections in germplasm,seed banks and tissue culture facilitiescare other possible ways to prevent extintion,but these are extremely expensive.

Fisheries

Fish is an importatn source of protein in many parts of the world.This includes both marine and freshwater fish.while the supply of food from fisheries has increased phenomenally between 1950 and 1990,in several parts of hte world fish catch has since dropped due to overfishing.In 1995 ,FAO reported that 44% of the world's fisheries are fully or heavily exloited-16% are alreay overexploited,6% are depleated and only 3% are gradually recovering .Canada had to virtiually close down cod fishing in the 1990s due to the serve depletion of its fish reserves.

Moderen fishing technologies using mechanized trawelrs and small meshed nets lead directly to overexpoilitation,which is not unsustainable.It is evident that fish have to breed successfully and need to have time to grow if the yield has to be used sustainably.The small traditional fisherman,who are no match for organized trawlers,are the worst affected by these developments.

Food security

It is estimated that 18 million people world wide,most of whom are children,die each year due to starvation or malnutrition,and manyothers suffer a variety if dietaary deficiencies.
The Earth can only supply a limited amount of food .if the world's carrying capacity to produce food cannot meet the needs of a growing population ,anarchy and conflict will follow.Thusmfood security is closelylinked with population control through the family welfare program.It is also lilnked to the availabilty of water for farming.Food security is only possible if food is equaitably distributed to all .Many of us waste a large amount of food carelessly.This eventually places great stress on our environmental resources.
Another major concern is the support needed for small farmers so that they remain farmers rather than shifting to urban centers as unskilled industrial workers.International trade polices in regard to an improved flow of food across national borders form those who have surplus to those who have a deflict in the developing world is another issue that is a concern for planners who deal with international trade concerns.'Dumping'of under-priced foodstuffs produced in the developed world on to markets in undevelopmeed countried=s undermines crop prices and forces farmers there to adopt unsustainable practices in order to compete .

More

These issues raise new questions as to how demandswill be met in future in future, even with a slowing down of population growth .Today,the world is seeling a changing trend in dietayhabits .As living standards are improving ,people are eating more non-vegeteraian food.As people change from eating grain to meat ,the world's demand for feed for livestock ,base on agriculture ,increases as well ,This uses more land per unit of food produced and the result is that the world's poor do not get enough to eat.
Women play an extremely vital role in food productin as well as in cooking meals and feeding children.In most rural communities they have the least exposure to technical training and to health workers trained in teaching/learning on issues related to nutritional aspects,women and girls frequently recieve less food than the men .These disparties need to be corrected .
In India there is a shortage of cltivatable productive land.Thus,farm sizes are too small too support a family on farm produce alone.with each generation famrs are being subdivivded further.poor environmental agricultural practices such as slash and burn ,shifitng cultivation or rab cultivation degrade the forests .
Globally ,5 to 7 million half of famland degraded eacj year.The loss of nutrients and the overuse of agricultural chemicals are major factors in land degradation.water scarcity is an important aspect of [ppr agricultural outputs.Salinization and water]-logging has aggected a large amount of agriculture worldwide.
The loss of genentic diversity in crop plants is another issue that is leading to a fall in agriculturral produce.Rice,wheat and corn are the staple foods of two-thirds of the world's grasslands,wetlands and other natural habitats are being lost ,the ability to enhance traits that are resistant to diseases,slinity,etc.,is also being lost.Genetic enginering is an untried and risky alternative to traditional cross-breeding.

World food Problems

IN many devellooping countries where populations are expanding rapidly,the production of food is unable to keep pace with the growing demand.Food production in 64 of the 105 developing countries is lagging behind their population gtowth levels.These countries to produce more food,or do not have the financial means to import it .India is one of the counry that have been able to produce enough food by cultivatinga large proportions of its arable and then through irrigation.The Green Revoltution of the '60s reduced starvation in country.However many of the technologies wehave used to achieve this are now being questioned.
* Our fertilite soils are being expoilted faster than they can recuperate.
* Forests, grasslands and wetlands have been converted to agricultural use,which has led to seerious ecological questions
* Our fish resources both marine and inland show evidence of exhaustion.

Food resources

Today our food comes almost entirely fom agriculture,animal husbanddry and finishing.Althrough india is self-sufficiant in food production,this is only because of modern tterns of agriculture that are unsustainable and which pollute our environment with excessive use of fertiizers and pesticides.
The FAO(Food and Agricultural organization)defines sustainable agriculture as that which conserves land,water and palnt and animal genetic resources does not degrade the environment and is economically vaible and socially acceptable.Most of our large fams frows several different crops,the chance of complete failure is lowered considerably .Many studies have shown that one can use alternatives to inorganic fertilizers and pesticides.This is known as integreated Crop management

Mineral Resources

A mineral is naturally occuring substanceof definite chemical compositon and identifiable physical properties.An ore is a mineral or combination of minerals from which a useual substance which a useful substance such as metal,can be extracted and used to manufacture useful products.
Minerals are formed over aa period of millianors of years in the Earth's crust.Iron aluminium,zinc,magnese and copper are important raw metirials for industrial use.Important non-metalic resources include coal,salt,caly,cement and silica.Stone used for building meterial ,such as grantle ,marble ,limestone,constitue anither category of minerals.Minerals with special special properties that human value for their aesthetic and ornametal value are gems such as diamonds,emeralds and rubies .The luster of gold,silver and platinum is used for ornaments .Minerals in the form of oil gas and coal were formed whe ancient plants and animals were converted in to underground fossil fuels.

Water for agriculture and power generation

India's increasing demand for water for intensive irrigated agriculture,for generating electracity,and for consumption in urban and idustrial centers,has been met by larging dans.The are under irrigationhas increased from 40 million has in 1900 to 100 million has in 1950 and to 271 million has by 1998.Dams support 30 to 40%of this area .

Althrough dans ensure a year-round supply of water for domestic use provide extra water for agriculture,industry and hydropower generation ,they are also accompainedby several serious environmental problems.They alter river flows,change nature's flood control machanismssuch as wetlands and flood plains,and destroy the lilves of local people and the habibates fo wild plant and animal species.

Intensive irrigation to support water-hungry cash crops like sugercane produces an uneequal distribution of water.Large landholders on the canals get the loins share of water.while smaller farmers get less and are adversely affected.

Drought

In most arid regions of the world the rains are very unpredictable.This leads to peropds when there is a serious scarity of water to drink,use in farms or provide for urban and industrial use,Drought-prone areas are thus faced with irregural periods of famine.Agriculture have no income in these bad years ,and as they have no steady income ,they have a constant fear of droughts .India has 'Drought-prone Areas Development progrms'which are used in suchareas to buffer the effects of droughts.Under these schemes, people are given wages in bad years to build roads,monor irrigation works and plantation programs.

Drought has been a major problem in our couintry,especially in arid and semi-arid regions.It is an unpredictable climatic condition and occurs due to the failure of one or more monsoons.It varies in frequency in diifent parts of our country.

while it is not feasible to prevent the failure of the monsoon .good environmental management can reduce its ill-effects.The scarcity of water during drought years affects homes agriculture and industry.It also leads to storagees and manitrution which especially affects children .

several measures can be taken to minimize the serious impacts of drought .However,this must be done as a preventive measure,so that if the monsoon fails its impact on local peoples lives is reduced.In years when the monsoon is adequate,we use up the good supply of water without trying to conserve it and use the water judiciously.Thus during a year whn the rains are poor,there is no water even for drinking in the drought area.

One factor that aggravates the effect of drought is deforstation.Once the hill-slopes are denuded of forest cover the rainwater rushes down the rivers and is lost.Forest cover permits water to be held in the area and gradually seep in to the ground.THis chargers the underground stores have been filled during a good monsoon .If water from the underground stores is overused,the water table drops and vegitation suffers.This soil and water management and afforestation are long-term measurs that reduce the impact of droughts.

Floods

Floods have been a serious environmental hazard for centuries.however the havoc raised by rivers overflowing their banks has become progressively more damaging as people have deforested catchmenrs and intensified the use of river flodd-plains that once acted as safety valves.The wetlands in flood -plains are nature's flood control systems in to which overfilled rivers could spill and they act like a temporary sponge holding the water,and preventing fast-flowing-water from damaging th esurrounding land.

Deforestation in the Himalayas causes floods that year after year kill people,damage crops and destroy homes in the Ganfes and its tributaries and Brhma putra,Rivers change their course during floods and tons of valuable soil is lost to the sea.

Global climate Change

Changes in climate at a global level caused by increasing air pollution has now begun to attract our climate,In some regions,global warming and the ElNino winds have created uncedented storms.In other areas,they lead to long droughts.Everywhere,the 'green house effect' due to atmospheric pollution is leading to increasingly erratic and unperdictable climate effects.This has seriously affected regional hydrological conditions.

over-utilization and pollution of surface and ground water

With the growth of human population ,there us an increasing need for larger amounts of water to fulfil a variety of basic needs.Today ,in many areas,this requirement cannot be met.The over-utilization of water occures at various levels .Most people use more water than they really need.Most of us waste water during a bath by using a shower or while washing clothes.May agriculturists use more water than necessary to grow crops .There are many ways in which farmrs can use less water with out reducing yields such as the use of drip irrigation systems.

Agriculture also pollutes surface water and underground water stores by the excessive use of chemical fertilizers ,and non-toxic pesticides,like neem products and using integrated pest management systems,all help to reduce the agricultural pollution of surface and ground water.

The industry tends to maximize short-term economic gains by not bothering about its liquid waste and releasing it into streams rivers and the sea.In .In the lonfer term as people become more consious of using 'green products' made by econsentive industries,the polluters products may not be used .The polluting industry that dies not care for tje environment and pays bribes to get away form the cost needed to use effulent treatments plants may eventually be caught ,punished and even closed which are already gaining in popularity.

As people begin to learn about the serious health hazards caused by pesticides in their food,public awarness may incresingly put pressures on industry to rpoduce only eco friemdly products which are already gaining in popularity.

Water Resources

The water cycle ,through evaporation and precipition,maintains hydrological systems which form rivers and lakes and supports a variety of aquatic ecosystems.Wet lands are the intermediate forms between terrestrial and aquatic ecosystems are used by a large number of people for their daily needs usch as drinking water,washing cooking watering animals and irrigating fiels.However the world depends on limited quantity of fresh water water covers 70% of the Earth's surface,but only 3% of this is fresh water .Of this 2% is present as polar ice caps and 1% is usable water in rivers,lakes and subsoil aquires.Only a fraction of this can be actually used.At global level,70% of the water is used agriculture 7% for industry and 3% for domestic use.
One of the greatest challenges facing the world in this century is the need to rethink the overall management of water resources.The world population has passed the billion mark based on the proporattion of young people in developing countries this will continues to increase significantly during the new few decades.This places enormous demands on the world's limited fresh water supply.The total annual fresh water withdrawls today are estimated at 3800 cubic kilometers twice as much as just 50 years ago (world commision on Dams,2000),Studies indiacate that a oerson needs a minimum of 20 to 40 liters of water per day for drinking and sanitation .However,more than one billion people worldwode have no access to clean water,and to many more,water supplies are unreliable

Deforestation

Those cilizations that looked agter the forests by using forest resources cautiously have proposed,whereas those that destroyed forests were gradually improverished,Today ,logging and mining are serious causes of loss of forests in our country and all over the world.Dams built for hydroelectic power or irrigation have submerged large tracts of forests and have displaced tribal people whose lives are closely knit to the forest.This has become a serious cause of concern in India.
One of India's serious environmental problems is forest degredation due to timber extraction and to cook thier meals and heat their homes.we have not been able to plant enough trees at a sufficent rate to support the need for timner and fuelwood.

Use and overexploition

People who live in or near forests know the value of forest resources first-hand ,because their lives and livelihoods depend directly on these resouceces.However,the rest of us also derive great benifits form the forests,which we are rearely aware of.The water we use depands on the istance of forest.we use many medicines that are based on forest produce amd we depend on plants for the oxygin they emit and to remove the carbon dioxide we breath out from the air.

Once upon a time,forests extended over large tracts of our country.People have used forests in our country for thousands of years .With the spread of agriculture,however the forests were left in patches which were controlled mostly by tribal people .They hunted animals and gathered plants and lived entirely on Forest resources.Deforestation became a major concern in British to develop sceintific forestry in India.They however aliented local people by creating Reserved and Protected Forests,which curtailed access to the resources .This led to a loss of stake in the consevations of the forest and to the gradual degraditon and fragmentation of forest across the length and breath of the country .

Another period of overutilization and forest degradation occured in the early period following independence as people felt that after the British had gone they had a right to use our forests in any way they pleased.The following years saw in India's residual forest wealth dwindle sparply.Timber extraction continued to remain the Forest Department's main concern up to the 1970s.The fact that forest degradation and deforestation was creating a serious of renue from timber.

Forest resources

Renewable Resources

Althrough water and boilogical living resources are considered renewable,they are ,infact renewable only with in certain limits They are linked to natural cycles,such as the water cylce.
*Fresh water(even after being used)evaporatesdue to the sun's energy ,forms water vapor and is re-formed in clouds,which fall to earth as rain,However,water sources can be overused or wasted to such anextent that theylocally run dry .Water sources can also become to heavily polluted by sewage and toxic substances that it becomes impossible to use the water
*Forests,once destroyed,take thousands of years to re-growin to fully -developed natural ecosystemswith their full complement of spices.Forestscan thus be said to behave like non-renewable resources if overused.
*Today,fish are being over-havested until the catch has become a fraction of the original resources and the fish are incapable of breeding successfullyto replenish the population.
*The out put of agriculture land,if mismanaged reduces by human activities until it cannot reproduce fast enough to maintain a viable number,the species becones extrict.
*Many spices are probably becoming extrict.with out us even knoimg and other linked species are affected by their loss.