Transcript
ECOSYSTEM-ECOSYSTEM-COMPONENTSCOMPONENTS
• An ecosystem comprises of two basic An ecosystem comprises of two basic componentscomponents
Abiotic components and Abiotic components and Biotic componentsBiotic components
• The relationship between the biotic components The relationship between the biotic components and abiotic components of an ecosystem is called and abiotic components of an ecosystem is called
'holocoenosis'. 'holocoenosis'. • Abiotic ComponentsAbiotic Components
These include the non-living, physico - chemical These include the non-living, physico - chemical factors such as air, water, soil and the basic factors such as air, water, soil and the basic
elements and compounds of the environment.elements and compounds of the environment.• Abiotic factors are broadly classified under three Abiotic factors are broadly classified under three
categories categories
• Abiotic factors are broadly classified under three categories.
• Climatic factors which include the climatic regime and physical factors of the environment like light, humidity, atmospheric temperature, wind, etc.
• Edaphic factors which are related to the structure and composition of soil including its physical and chemical properties, like soil and its types, soil profile, minerals, organic matter, soil water, soil organisms.
• Inorganic substances like water, carbon, sulphur, nitrogen, phosphorus and so on. Organic substances like proteins, lipids, carbohydrates, humic substances etc.
• Biotic Components
• It comprises the living part of the environment, which includes the association of a number of interrelated populations belonging to different species in a common environment.
• The populations are that of animal community, plant community and microbial community.
• Biotic community is distinguished into autotrophs, heterotrophs and saprotrophs.
• Autotrophs (Gr: auto - self, trophos - feeder) are also called producers, convertors or transducers.
• These are photosynthetic plants, generally chlorophyll bearing,
• which synthesize high-energy complex organic compounds (food) from inorganic raw materials with the help of sunlight, and the process is referred as photosynthesis.
• Autortophs form the basis of any biotic system.
• In terrestrial ecosystems, the autotrophs are mainly the rooted plants.
• In aquatic ecosystems, floating plants called phytoplankton and shallow water rooted plants called macrophytes are the dominant producers.
• Heterotrophs (Gr: heteros - other; trophs - feeder) are called consumers, which are generally animals feeding on other organisms.
• Consumer's also referred as phagotrophs (phago - to ingest or swallow) or macroconsumers are mainly herbivores and carnivores.
• Herbivores are referred as First order consumers or primary consumers, as they feed directly on plants
• For e.g., Terrestrial ecosystem consumers like cattle, deer, rabbit, grass hopper, etc.
• Aquatic ecosystem consumers like protozoans, crustaceans, etc.
• Carnivores are animals, which feed or prey upon other animals.
• Primary carnivores or Second order consumers include the animals which feed on the herbivorous animals.
• For e.g., fox, frog, predatory birds, smaller fishes, snakes, etc.
• Secondary carnivores or Third order consumers include the animals, which feed on the primary carnivores.
• For e.g., wolf, peacock, owl, etc.
• Secondary carnivores are preyed upon by some larger carnivores.
• Tertiary carnivores or Quaternary consumers include the animals, which feed on the secondary carnivores.
• For e.g., lion, tiger, etc. • These are not eaten by any other
animals.• The larger carnivores, which cannot be
preyed upon further are called top carnivores.
• Saprotrophs (Gr: sapros - rotten; trophos - feeder) are also called decomposers or reducers.
• They break down the complex organic compounds of dead matter (of plants and animals).
• Decomposers do not ingest their food. Instead they secrete digestive enzymes into the dead and decaying plant and animal remains to digest the organic material.
• Enzymes act upon the complex organic compounds of the dead matter.
• Decomposers absorb a part of the decomposition products for their own nourishment.
• The remaining substances are added as minerals to the substratum (mineralisation).
• Released minerals are reused (utilised) as nutrients by the plants (producers).
Structure and functionStructure and function
• The characteristic structure of an ecosystem is obtained by the systematic physical organisation of the abiotic and biotic components of that particular ecosystem.
• The two main structural features of any ecosystem are its 'species composition' and 'stratification'.
• An ecosystem can be represented by depicting the producers - consumers relationship in the given ecosystem.
• This is also called the 'Trophic structure' of an ecosystem, wherein each animal population forms the various trophic levels.
• The producers (green plants) always form the first trophic level. Herbivores, which feed on producers, are at the second trophic level followed by secondary consumers, tertiary consumers and so on.
• Trophic structure of an ecosystem can be described in terms of its total amount of nutrients or the amount of living material.
• The amount of nutrients in the soil at any given time is referred as 'standing state' whereas the amount of living material is referred as 'standing crop'.
• Function• The functional attributes of an ecosystem helps
to keep its component parts running together. • Few important functional aspects of an
ecosystem are:• Biological diversity and maintenance of stability• The numerical strength and biomass of
organisms affect the functioning of ecosystem.
• The numerical strength and biomass of organisms affect the functioning of ecosystem.
• In ecosystems, the biotic communities usually contain a few common species represented by a large number of individuals or
• by a large biomass and a comparatively large number of individual species occurring in small numbers.
• Under stress conditions, the number of rare species is usually reduced, and only a few species may survive and their frequency of occurrence may be very high.
• As a rule, the total number of species in any ecosystem is reduced under conditions of extreme stress, as found in arctic, antarctic and desert region and so on.
• A system is considered stable in the ecological sense if its structure and functions remain more or less the same from year to year.
• A system with high species diversity and low dominance is less productive but stable.
• On the other hand, a system with a community with low species diversity and high dominance is more productive but unstable
ENERGY FLOW IN AN ENERGY FLOW IN AN ECOSYSTEMECOSYSTEM
• Energy is the capacity to do work. Solar energy is transformed into chemical energy by the process of photosynthesis,
• and is stored in plant tissue and then transformed into mechanical and heat forms during metabolic activities.
• The energy, in the biological world, flows from the sun to plants and then to all heterotrophic organisms such as microorganisms, animals and man.
Food chainFood chain• "Food chain is a series of groups of
organisms called trophic levels, in which, there is repeated eating and eaten by so as to transfer food energy".
• OR• "The series of populations or organisms of an
ecosystem through which food and energy contained in it passes with each member becoming the food of the later is called a food chain".
• a) Food chain observed in a river:
• ) Food chain observed in a pasture:
• The transfer of food energy from plant sources through a series of organisms forms a 'food chain'.
• The base of the food chain is always formed by a plant (producer / autotroph), which is grazed on by a herbivore, which is predated over by a carnivore, which may be eaten by another carnivore.
• A food chain, can therefore, be represented as,
• where each link represents a trophic level.
Characteristics of food chainCharacteristics of food chain• In a food chain, • a) there is repeated eating in which each group
eats the smaller one and is eaten by the larger one. Thus, it involves a nutritive interaction between the biotic components of an ecosystem.
• b) the plants and animals which depend successively on one another form the limbs of a food chain.
• c) there is unidirectional flow of energy from sun to producers and then to a series of consumers of various types.
• Thus, a food chain is always straight and proceeds in a progressing straight line
• d) usually 80 to 90% of potential energy is lost as heat at each transfer on the basis of second law of thermodynamics (transformation of energy involves loss of unavailable energy).
• e) usually there are 4 or 5 trophic levels. Shorter food chains provide greater available energy and vice - versa.
• f) omnivores occupy more than one trophic level and, some organisms occupy different trophic positions in different food chains
Types of foodchainTypes of foodchain• There are mainly two types of food chains operating
in nature. • a) Grazing food chain• b) Detritus food chain. • Grazing food chain is generally seen in ecosystems
such as grassland, pond or lake where a substantial part of the net primary production is grazed on by herbivores (cattle and rodents).
• Usually upto 50% of the NPP is grazed on by these animals in their respective ecosystems and the remaining 50% goes to the decomposer organisms as dead organic matter.
• Thus, in these ecosystems, the food chain is herbivore based.
Characteristics of foodchainCharacteristics of foodchain• Food chain studies help, • a) understanding the feeding relationships
and the interaction between organisms in any ecosystem.
• b) comprehend the energy flow mechanism and matter circulation in ecosystems.
• c) understand the movement of toxic substances and the problem of 'Biological magnification' in the ecosystem.
• d) analyse the biological diversity in an ecosystem.
• In nature, food chain relationships are not isolated.
• They are very complex, as one organism may form the food source of many organisms.
• Thus, instead of a simple linear food chain, there is a web like structure formed by these interlinked food chains.
• Such interconnected matrix of food chains is called 'food web'.
Food webFood web• Food web can be defined as, "a network
of food chains which are interconnected at various trophic levels,
• so as to form a number of feeding connections amongst different organisms of a biotic community".
• Food webs are indispensable in ecosystems as they allow an organism to obtain its food from more than one type of organism of the lower trophic level.
• Generally, a food web operates according to taste and food preferences of the organism, yet availability of food source and other compulsions are equally important.
• For e.g., tigers normally do not eat fish or crabs, but Sunderbans they are forced to feed on them in the absence of their natural prey.
A Food Web in Terrestrial A Food Web in Terrestrial and Aquatic Ecosystemand Aquatic Ecosystem
Ecological pyramidsEcological pyramids
• Ecological pyramids can be defined as, • "a geographical representation of an
ecological parameter like number of individuals or amount of biomass or amount of energy present in various trophic levels of a food chain with producer forming the base and top carnivores at the tip".
• Graphical representation of the trophic structure is done by drawing ecological pyramids, where the basal, mid and top tiers show the parameter values for producers, herbivores and carnivores in the ecosytsem.
• An ecological pyramid may be upright (tapering towards the tip), or inverted (widens towards the tip) or spindle shaped (broader in the middle and narrow above and below).
• On the basis of the parameters used, ecological pyramids are of three types.
• Pyramid of Numbers • Pyramid of Biomass • Pyramid of Energy • "Pyramid of numbers is the graphic
representation of number of individuals per unit area of various trophic levels stepwise with producers forming the base and top carnivores the tip".
Pyramid of Numbers in a Pyramid of Numbers in a Grassland Ecosystem Grassland Ecosystem
• The shape of the pyramid of numbers vary from ecosystem to ecosystem.
• In aquatic ecosystems and herbaceous communities, autotrophs are present in large numbers per unit area.
• They support a lesser number of herbivores, which inturn support fewer carnivores
Pyramid of Numbers in a Pyramid of Numbers in a Aquatic Ecosystem Aquatic Ecosystem
• So, the producers are smallest sized but maximum in number while, top carnivores are larger in size but lesser in number,
• so these cannot be used as prey by another.
• Hence the pyramid of numbers is upright
• In a parasitic food chain, for e.g., an oak tree, the large tree provides food to several herbivorous birds.
• The birds support still larger population of ectoparasites leading to the formation of an inverted pyramid.
• When a large tree support larger number of herbivorous birds which inturn are eaten by carnivorous birds like falcon and eagle, which are smaller in number, it forms a spindle shaped pyramid.
• Pyramid of biomass is the graphic representation of biomass present per unit area of different trophic levels, with producers at the base and top carnivores at the tip".
• The total amount of living or organic matter in an ecosystem at any time is called 'Biomass'.
• In a terrestrial ecosystem, the maximum biomass occurs in producers, and there is progressive decrease in biomass from lower to higher trophic levels.
• Thus, the pyramid of biomass in a terrestrial ecosystem is upright.
• In an aquatic habitat the pyramid of biomass is inverted or spindle shaped where the biomass of trophic level depends upon the reproductive potential and longivity of the member.
• Pyramid of energy is a graphic representation of the amount of energy trapped per unit time and area in different trophic level of a food chain with producers forming the base and the top carnivores at the tip".
• Representation of Pyramid of Energy • Pyramid of energy is always upright.• It is so because at each transfer about
80 - 90% of the energy available at lower trophic level is used up to overcome its entropy and to perform metabolic activities.
• Only 10% of the energy is available to next trophic level (as per Lindemann's ten percent rule).
Forest ecosystemForest ecosystem• In the Forest ecosystem animals are
the consumers.• They influence the flow of energy and
cycling of nutrients through systems as well as structure and composition of forests through their feeding behaviour and the disturbances that they create.
• In turn their abundance and diversity is influenced by the composition of the forest and the various disturbances that occur in the forest.
• Animals in an ecosystem form the heterotrophic stratum or brown belt of an ecosystem .
• The animals in the ecosystem can be classified on the basis of their feeding habits into:-
• 1. Herbivores are animals that consume plants and get their energy by eating plants.
• They form the primary consumers of the ecosystem.Cow ,sheep ,goat ,deer,rabbit,horse ,zebra are some of the herbivorous animals.
• Carnivores or predators are animals that feed on the herbivores or other animals in order to derive energy and nutrients required for their diet.
• They form the secondary consumers of the ecosystem.Mammals like dogs,cats,mongoose ,hyennas;
• birds like hawks,eagle,falcon, reptiles like crocodile,snake,turtles are examples of carnivorous animals.
• The tertiary consumers are also carnivores that feed on primary consumers like herbivores and also feed on secondary consumers .
• Lion,tiger are examples of tertiary consumers.
• Scavengers are flesh eaters and eat the dead flesh from left over of the carnivores.
• Jackal,vultures are examples of scavengers.
• 4.Parasites are organism consumes blood or tissues of the host animal without killing the host.
• 5.Decomposers break down complex compounds of dead tissues of producers and
• consumers,absorb some of the decomposition products and release simple substances consumable by autotrophic organisms.
• Decomposers include earthworms,bacteria, fungi,actinomycetes etc.
TYPES OF FOREST TYPES OF FOREST ECOSYSTEMECOSYSTEM
• The forest ecosystem is of 3 types-tropical rain forest,tropical deciduous forest and temperate coniferous forest.
• Tropical rain forest provides both shelter and food for huge number of animals which include birds like cuckoo bird,parrot ,swallows humming bird eagles;mammals like orangutans ,monkeys gibbons,tiger,foxes,hippopotamus,jaguar,reptiles like crocodiles,alligators,anaconda,flying gecko etc.
• Tropical deciduous forest contains animals like deer,elephants,sambars ,cheetahs,wild buffaloes tiger ,leopard.Birds ,reptiles,amphibians are also found in abundance.
• Coniferous forests consists of rich and varied animal life which includes mammals like mouse deer,musk, rat,porcupine,rabbit,squirrels etc;
• insectivorous birds like grouse,jay cross bill etc and reptiles like snakes and lizards.
ROLE OF ANIMALS IN ROLE OF ANIMALS IN FOREST ECOSYSTEMFOREST ECOSYSTEM
• Animals play a very important role in forest ecosystem.
• Pollination: • Majority of flowering plants use a range
of animals of the forest as pollinating agents.Bees,butterflies, beetles,birds like sun birds,humming birds,bats are common pollinating agents.
• Often flowers of animal pollinating plants are specially adapted for a particular species of animal
• Seed dispersal:Many animals of the forest play important role in dispersal of seeds from one place to another.Some plants colourful flowers,chemicals which helps to attract certain species of animals.
• Decomposition,mineral recycling and soil improvement:
• These are mostly controlled by soil organisms,which can significantly influence physical and chemical properties of the soil.
• The decomposers degrade complex animal tissue ,decompose carbon compounds and convert plants residues into humus and improve the fertility of the soil.
• Flora refers to plant species and fauna refers to animal species.
• The term biota includes both plant as well as the domesticated and wild species of animals.
• Our country has a rich diversity of flora and fauna.
• There are over 45,000 plant species and 81,251 animal species. It represents about 7% of world's flora and 6.5% of world's fauna.
• Plants are the main source of food, fodder and other useful things such as fuel (fire wood), fibre, timber, medicine, gums, tannin etc.
• Flora and fauna of India form the following two most important natural resources
Uses of forestUses of forest• Forests can be described as uncultivated
and uninhabited pieces of land covered by trees and shrubs.
• Forests play a vital role in the life and culture of the people.
• They form an important renewable natural resource.
• India has about 63.5% million hectares of forests and forms 1/5th of the geographical area of the country.
• Forests are intimately linked with our culture and civilization. Forests are useful to us in many ways:
• Forests provides timber for the furniture and building
• Forests provides raw material for paper, board and plywood industry
• Forests provides fodder for cattle, sheep, goat and other animals
• Forests provides bamboo which is called poor man's timber
• Forests gives protection to wild life • Forests helps in balancing the carbon
dioxide and oxygen in the atmosphere. During photosynthesis, plants release O2 and use CO2 thus, they put check on the green house effect.
• Forests regulate the earth's temperature and weather cycle. They enhance local rainfall
• Forests check soil erosion, landslides and also prevent floods
• Forests protect wild life • Forests also provide fruits, nuts, gums,
rubber, dyes, fibre, medicines, camphor, essential oils etc.
• Forests are major sources of various animal products such as honey, wax, tussore, lac etc.
wild lifewild life• Naturally occurring animals, plants and
their species, which are not cultivated, domesticated and tamed, are called wild life.
• The Indian fauna includes variety of animal life such as mammals, birds, reptiles, fishes, insects etc i.e. about 800 species of mammals, 2000 species of birds, 420 species of reptiles, 2000 species of fish, 50,000 species of insects, 4000 species of molluscs
• The animals like black buck, nilgiri tahr, pigmy hog, golden langur, lion tailed macaque etc are unique to India.
• Wild life has links in food chain from which we derive benefits.
• Rodents and different insects are controlled by hawks, kites and snakes.
• It plays a vital role in biological control and maintains ecological balance in forests.
• When man destroys wild life, the ecological balance is upset.
• When forests are destroyed, harmful insects such as caterpillars, borers, and moths increase in number since birds are no longer there to eat them.
Grassland ecosystemGrassland ecosystem• Any unit that includes all the organisms
i.e. the communities in a given area,• interact with the physical environment
so that a flow of energy leads to clearly defined trophic structure,
• biotic diversity and material cycle (exchange of materials between living and non living components) within the system, known as an ecological system or ecosystem.
• The term ecosystem is derived from two different words, eco = environment ; system = an interacting, interdependent complex.
• About Ecosystem• Grassland is a type of terrestrial
ecosystem.• Grasslands occupy a comparatively
fewer area, roughly 19% of the earth’s surface.
• The various components of a grassland ecosystem are as follows
• Abiotic components-• These are nutrients present in soil and
the aerial environment. • Thus, the elements like C, H, O, N, P, S
etc. are supplied by carbon dioxide, water, nitrates, phosphates and sulphates etc., present in air and soil of the grassland.
• Moreover, in addition to the above, some trace elements are also present in soil.
• Biotic components-• These may be categorized as:• 1. Producers- They are mainly grasses.
Besides them a few herbs and shrubs also contribute to primary production.
• 2. Consumers- These occur in the following sequence:
• a) Primary consumers- In grasslands, the herbivores feeding on grasses are mainly such grazing animals as cows, buffaloes, deer, sheep, rabbit, mouse etc.
• Besides them, there are also present some insects that feed on the leaves of grasses.
• Secondary consumers- • These are the carnivores feeding on
herbivores. • These include the animals like fox,
jackals, snakes, frogs, lizards, birds etc. • Sometimes the hawks feed on the
secondary consumers, thus occupying tertiary consumer level in the food chain.
• 3. Decomposers- • The microbes active in the decay of dead
organic matter of different forms of higher life are fungi, and some bacteria and actinomycetes.
• They bring about the minerals back to the soil, thus making them available to the producers.
Desert ecosystemDesert ecosystem• A desert ecosystem may seems to be
barren land and devoid of life but plants and animals do exist in desert.
• But their number of plants and animals is not as large as that in other ecosystems.
• A desert ecosystem is a type of arid ecosystem that exists where there is very little rainfall and the climate is usually extreme in harshness.
• Other arid ecosystems are semidesert, subdesert, steppe, and semiarid or arid grasslands.
• Due to the low moisture content in desert the biological activities are regulated by ephemeral water availability .
• These ecosystems are either barren or with scanty vegetation consisting of mainly thorny bushes.
• Deserts are classified as warm (hot) and cold (temperate) deserts.
• The hot deserts are the Sahara in Northern Africa, Kalahari in Southern Africa, Thar in India, Atacama in South America, deserts of Mexico and Australia.
• The deserts of Iran and Turkey, Gobi desert of Mongolia, some deserts of Argentina are recognised as temperate or cold deserts.
Plants in Desert Ecosystem Plants in Desert Ecosystem • Plants in the desert ecosystem are
generally dwarfed because of the lack of rainfall.
• The most common plant that is seen in the desert ecosystem is the cactus.
• More than hundreds of different types of cactus are found in desert ecosystem and each one has evolved to suit the particular desert ecosystem to which they are endemic.
• Other plants of desert ecosystem are saltbush and gravillias.
• Plants of the desert ecosystem have evolved with succulent bodies that can retain the precious moisture needed for growth and narrow needle like leaves that reduces the lose moisture easily.
• Other plants spread across the ground or grow under shades of larger plants.
Animals in Desert Animals in Desert EcosystemEcosystem
• Animals present in the desert ecosystem include very few large mammals but camel is one of the prominent animals found in this environment.
• Other animals found in desert ecosystem includes rats, small rodents, rabbits, moles and fox like creatures.
• Burrowing creatures, snakes, insects, ants, birds, lizards, and beetles are regular inhabitants that are found in desert ecosystem
• Animals and other creatures present in desert ecosystem have managed to survive in the harsh climate, hot days and freezing nights, by controlling their body heat.
• It is essential for any desert ecosystem animals to adjust to the particular aspects of their environment.
• The fragile balance of the desert ecosystem is nowadays damaged by excess human activity.
Characteristics of DesertsCharacteristics of Deserts• i) Most deserts receive some rain every
year but not uniform. • ii) Light green covering of annuals is
seen just after rains.• iii) Have scanty vegetation, clear skies,
hot days and extremely cold nights. • iv) Soil is rocky and encrusted with
sand or salt.
• Long periods without precipitation and extreme temperature (50 - 60oC) conditions (arid lands) impose considerable restraints on the flora and fauna which inhabit there.
• Sandy storms are very frequent.• Occur generally in rain shadow areas.
• Flora• 1) Includes succulents such as Cacti and
Euphorbias, which can store water in their tissues.
• 2) Trees with long spreading roots such as Acacia, Prosopis, Phoenix (dates) are found.
• 3) Ephemerals (short lived) such as Boerhaavia repens are seen only during rainy season.
• Fauna• Most desert animals are nocturnal and
avoid the heat of the day by burrowing into the cooler soil.
• Animals include ants, locusts, lizards, Gila monster, coral snake, rattle snake, burrowing owls, Gambel's quail, kangaroo rats, rabbits, camel, skunk, badger foxes, jackals and desert cats.
• In general, the organisms having specialised structural and physiological and behavioural adaptations to withstand the extreme temperatures only can survive in a desert.
Aquatic ecosystems Aquatic ecosystems • .Ecosystem is an biological community of an
area, of interacting organisms and their physical and chemical environment.
• Earth’s surface can be described by a series of interconnected ecosystems. Ecosystem can be classified into 2 main categories:
• Terrestrial ecosystems: where organisms and their environment interacts on landmasses.
• Aquatic ecosystems: where plants, animals and their physical environment interact in water.
Types of Aquatic Types of Aquatic EcosystemsEcosystems
• . Fresh water:• Very small proportion of earth’s area that is
only 0.8 percent of the earth’s surface is covered by them.
• Primary production in a fresh-water ecosystem is controlled by light and nutrient availability.
• Fresh water can be defined as the water that contains a relatively small amount of dissolved chemical compounds.
• It includes :Standing Water- lakes & ponds and Moving Water- rivers & streams
• Standing Water- lakes & ponds:• Standing water ecosystems are known as
Lentic ecosystems such as lakes and ponds.
• The organisms in lentic ecosystem includs algae, rooted and floating-leaved plants, invertebrates such as crabs, shrimps, crayfish, clams etc, amphibians such as frogs and salamanders; and reptiles like alligators and water snakes.
• Moving Water- rivers & streams:• flowing-water ecosystems are known as
Lotic ecosystems with water flowing in uniform direction and in a unidirectional way.
• Examples are rivers and streams, which harbor several species of insects and fishes.
• Crustaceans like crayfish and crabs; and mollusks such as clams and limpets.
EstuariesEstuaries• Areas where freshwater dumps into
ocean.• So the water is neither truly fresh
water, since it has salt content, but it is also not consider salt water because it has a lower level of salt than the ocean.
• Estuaries are always productive and has rich biodiversity. Organisms are well adapted to varying levels of salinity.
• Wetlands- bogs/fens, swamps, marshes: Here the water is completely or partially shallow.
• Has a rich biodiversity because they receive plenty of sunlight which supports life.
• Plants include water lilies, mangrove, tamarack and sedges are commonly found in wetlands.
• Various species of reptiles and amphibians are also found in wetlands.
Marine Ecosystem Marine Ecosystem • About 71% of the earths surface is
covered by marine ecosystem. Marine ecosystem involves:
• Shorelines, Coral Reefs, Open Ocean• Shorelines : are where oceans and seas
meet land. • Since its close to the sea its always
prone to hurricanes and erosion.Habitat fo burrowing animals.
• Coral Reefs: Cover less than 1% of the oceans.Also known as “Rainforests of sea”.
• These are clear warm shallow sea’s.Made up of as a result of accumulation of calcium carbonate deposited by marine organisms like corals and shellfish.
• Open Ocean: Oceans have a great impact on the biosphere.Its the source of rainfall.
• ocean temperatures determine climate and wind patterns
• Significance of Different Types of Aquatic Ecosystems
• The study of aquatic ecosystem helps to understand the biodiversity (flora and fauna)of the aquatic ecosystem and their interaction with the physical and chemical environment .
• Aquatic ecosystems are in danger mainly because of human activities like: Overfishing, Transportation, waste disposal , recreation and other activities which might harm the ecosystem
BiodiversityBiodiversity• The term biodiversity has been derived
from two Greek words bios = life; diversity = forms. It is in fact, the shortened form of biological diversity.
• Biodiversity can be defined as the vast array of species of micro-organisms, algae, fungi, plants and animals occurring on the earth.
• In other words biological diversity refers to the variety of all living organisms and their natural habitats found in a defined area.
• "Biological diversity" means the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part ; this includes diversity within species, between species and of ecosystems
• Biodiversity differs from place to place. This is because of the environmental conditions of that place.
• This explains why different species live in different areas or specific areas and not in others.
• Levels or Aspects of Biodiversity• Genetic Diversity • Species Diversity • Ecosystem Diversity
Genetic diversityGenetic diversity
• It refers to the variation of genes within a species.
• The genetic diversity enables a population to adapt to its environment and to respond to natural selection.
• The amount of genetic variation is the basis of speciation.
• Genetic diversity within a species often increases with environmental variability.
Species diversitySpecies diversity
• Species are distinct units of diversity each playing a specific role in the ecosystem.
• Species diversity refers to the variety of species within a region.
• In nature, both the number and kind of species, as well as the number of individuals per species vary, leading to greater diversity.
• The different sample areas showing species richness (sample area 1),
• Species evenness (sample area 2) and
• diversity due to taxonomically unrelated species (sample area 3)
Community and ecosystem Community and ecosystem diversitydiversity
• Diversity at the level of community and ecosystem exists along 3 levels.
• It could be within-community diversity (alpha diversity), between-communities diversity (beta diversity) or
• diversity of the habitats over the total landscape or geographical area (gamma diversity).
Three perspectives of diversity: Three perspectives of diversity: alpha, beta and gamma alpha, beta and gamma
diversitydiversity
Threats to biodiversityThreats to biodiversity• Habitat loss and fragmentation,
disturbance and introduction of alien species pore greatest threats to biodiversity.
• Exotic species have large impacts in island ecosystems.
• Classification of threatened species• Any species of wild life likely to
disappear from the world sooner or later is called a threatened species.
• The international union of conservation of nature and natural resources (IUCN) has classified the threatened species of wild life into 3 categories for the purpose of conservation.
• The classification is based on the following factors:
• a) The past and present distribution of the species.
• b) The decline in the number of population in course of time.
• c) Abundance and quality of natural habitat of the species.
• d) The biology and potential value of the species.
Categories of threatened Categories of threatened speciesspecies
Some endangered species Some endangered species of India of India
• Endangered (E)• These are the species whose
populations have decreased or habitats have been reduced to the levels that pose immediate danger of extinction. Their survival is unlikely if the causal factors threatening their existence continues.
• Examples: Great Indian Bustard • Pink Headed Duck
• Vulnerable (V) species• This category includes the species who
are likely to move into the endangered category in the near future, if the causal factors continue to be operating.
• These are species whose populations have been seriously depleted and whose ultimate security is not assured and also those whose populations are still abundant but are under threat throughout their range.
• Rare (R) species• These are species with small populations
in the world. They are confined to limited areas or are thinly distributed over a more wide area.
• They are not at present endangered and vulnerable but are at risk.
• Example: Two species of Asiatic pheasants
• d) Threatened (T) species• The term threatened is used in the
context of conservation of the species which are in any one of the above 3 categories.
Importance of biodiversityImportance of biodiversity• Biodiversity is the variety and variability of
the living organisms on the earth. • This includes all plants and animals and their
habitats most of which are the severe threats of extinction.
• Biodiversity is vital for evolution and for maintaining life sustaining systems of the biosphere.
• The importance of biodiversity lies in ecological, genetic, social, economic, scientific, educational, cultural, recreational and aesthetic significance
Importance of Biodiversity Importance of Biodiversity in Terms of Resource Valuesin Terms of Resource Values
• The material resources signifying the importance of biodiversity include food, water, drugs, oil, genes for biotechnology, building materials.
• Plants and animals act as major food resources of most living organisms signifying the importance of biodiversity.
• Global climatic change results due to large shifts in natural vegetation and in agricultural systems.
• The insurance importance of biodiversity is also evident in the fact that increased genetic uniformity is correlated with the increase crop yield variation.
• Forests plays important role in watershed regulation and stabilization of soil in erosion prone areas.
• Mangroves aid in coastal zone stabilization and as nursery areas for fishery species.
• Medical herbs act as potent sources of drugs contributing to the global health care. Even usage of animals like leeches, horse shoe crabs signify the importance of biodiversity.
• Natural ecosystems are protected as national parks in generating income for wildlife tourism.
• The ornamental plants like orchids are important commodity in international trade with an expanding international market.
• The beneficial organisms like honey bee, lac insects, various domestic animals, fishes also cite the importance of biodiversity
Importance of Biodiversity in Importance of Biodiversity in Terms of Non-resource ValuesTerms of Non-resource Values
• The non material resources signifying the importance of biodiversity include the spiritual well being, knowledge, ethical values.
• From different cultural background, ethical and religious issues lay the importance of biodiversity.
• The generalized aesthetic sense of man supports the importance of biodiversity.
• Deer, game bird, wildfowl are important aspects of sports hunting.
• The importance of biodiversity lies in recreation and tourism as well as social and cultural well being of man. Wildlife has influenced human philosophy, language and art from time immemorial.
Threats and biosphere Threats and biosphere reservesreserves
• The concept of biosphere reserves has been evolved by UNESCO's Man and Biosphere Programme (MABP).
• A biosphere reserve is a specified area in which multiple use of the land is permitted by dividing it into zones, each for a particular activity.
• Zones of biosphere reserve• A biosphere reserve is divided into 3
zones - Core, Buffer and Manipulation.
• The zones of biosphere reserve• a) Core zone• No human activity is allowed in this zone.
Comprises of legally protected ecosystem.
• b) Buffer zone• Limited human activity is permitted in the
buffer zone.• c) Manipulation zone or Transition zone• Several human activities can occur in the
manipulation zone.• Example: Settlements, cropping, forestry,
recreation etc.
Role of biosphere reservesRole of biosphere reserves• A biosphere reserve preserves• a) wild population • b) life style of tribals• c) genetic resources of domesticated
plants and animals. • It helps in• 1) conservation • 2) promotes economic development• 3) Scientific research, monitoring and
education
Biosphere Reserves of IndiaBiosphere Reserves of India
Popular National Parks and Popular National Parks and Sanctuaries in IndiaSanctuaries in India
The Biosphere Reserves in The Biosphere Reserves in IndiaIndia
• Sacred forests and sacred lakes• A traditional strategy for the protection
of biodiversity has been in practice in India and some other Asian countries in the form of sacred forests.
• These are forest patches of varying dimensions protected by tribal communities due to religious sanctity accorded to them.
• In India sacred forests are located in several parts.
• For e.g., Karnataka, Maharashtra, Kerala, Meghalaya etc. and are serving as refugia (an area in which a population of organisms can survive through a period of unfavourable conditions) for a number of rare, endangered and endemic taxa.
• Similarly several water bodies (e.g., Khecheoprai lake in Sikkim) are declared sacred by people.
• This indirectly leads to protection of aquatic flora and fauna.
HOTSPOTS OF BIO-HOTSPOTS OF BIO-DIVERSITYDIVERSITY
• Biodiversity is not uniformly distributed across the geographical regions of the earth.
• Norma Myers developed the hot spots concept in 1988 to designate priority areas for in-situ conservation.
• The hot spots are the richest and the most threatened reservoirs of plant and animal life on earth.
• The key criteria for determining a hot spot are:
• i) Number of endemic species i.e., the species that are found nowhere else
• ii) Degree of threat, which is measured in terms of habitat loss.
• The terrestrial biodiversity hot spots • Twenty-five terrestrial hot spots for
conservation of biodiversity have been identified worldwide.
• Among the twentyfive hot spots of the world, two (Western Ghats and Eastern Himalayas) are found in India.
ENDANGERED AND ENDEMIC ENDANGERED AND ENDEMIC SPECIES OF INDIASPECIES OF INDIA
• Many animal species have either become extinct or are on the verge extinction. This is because of continuous and constant exploitation by man.
• The International Union for Conservation of Nature and Natural resources (IUCN) have printed out five main conservation categories of wild animal and plants.
• Conservation Categories Of Wild Animals And Plants
• Conservation Categories Of Wild Animals And Plants
• Extinct Species• A species is considered extinct when there is no
reasonable doubt that its last individual has died, e.g., mountain quail, pink headed duck, one horned rhino and cheetah.
• Endangered Species• The IUCN Red List is a catalogue of taxa that
are facing the risk of extinction.• The red list aims to impart information about
the urgency and scale of conservation problems to the public and policy makers
• The use of the Red List are • i) Developing awareness about the
importance of threatened bio diversity.• ii) Identification and documentation of
endangered species. • iii) Providing a global index of the decline
of biodiversity• iv) Defining conservation priorities at the
local level and guiding conservation action.
• The world conservation union (formerly IUCN) has recognised 8 Red List Categories of species.
• 1) Extinct • 2) Extinct in the world• 3) Critically endangered • 4) Endangered5) Vulnerable • 6) Lower risk• 7) Data deficient • 8) Not evaluated• The 2000 Red List contains assessments of
more than 18,000 species, 11,000 of which are threatened.
• The 2000 Red List contains assessments of more than 18,000 species, 11,000 of which are threatened.
• The Red List also provides information to international agreements such as the convention on Biological diversity and the convention on International Trade in Endangered Species of Wild Fauna and Flora.
• According to the Red List, in India • 44 plant species - critically endangered• 113 plant species - endangered • 87 plant species - vulnerable• 18 animal species - critically endangered • 54 animal species - endangered• 143 animal species - vulnerable
• The percentage of threatened angiosperms, amphibians, reptiles, birds and mammals categorised as Critically Endangered, Endangered, Vulnerable and at Lower Risk
• Species which are in danger of extinction and whose survival is unlikely if the causal factors continue to operate.
• e.g., Brow antlered deer, hispid hare, Indian rhinoceros, Great Indian bustard, musk deer, blue whale etc. Vulnerable Species
• Such a species contains sufficient number of individuals in its habitat but in the near future, may becme an endangered species if unfavourable conditions persist. e.g., crab eating macaque, golden langur, chinkaro deer etc.
• Rare Species• Species that are not presently
endangered or vulnerable but are at risk e.g., Indian egg eating snake, Indian pied hornbill and golden cat fall in this category.
• Insufficiently Known Species• These are species about which there is
not enough information.
• It is published by IUCN, to provide information about threatened species of plants and animals.
• Indian Green Book• Botanical survey of India publishes this
book. • This book provides information about
plant species which are rare, endangered or endemic, but all of which are grown in botanical gardens.
• The number of plant and animal species of various threat categories in India
• Examples of Threatened species in India
Important Measures for the Important Measures for the Conservation of Indian Wild Conservation of Indian Wild
LifeLife
• In Situ Conservation• This is conservation of living resources within
the natural ecosystem in which they occur. • This is acheived by protection of natural
habitat and maintenance of endangered species in certain protected areas such as national parks, wild life or bird sanctuaries and biosphere reserves.
• In India, there are about 73 national parks, 416 sanctuaries and 12 biosphere reserves
• National Parks• This comprises area which is dedicated
for conservation of the environment, natural objects and the wildlife therein.
• Forestry operations are prohibited and it is open to visitors who are not allowed to disturb or harm the protected plants or animals.
• Sanctuaries• They are meant to protect and conserve
particular species of wildlife.• They are not bound by state legislation.
Killing, hunting or capturing of any animal species is prohibited.
• Forestry and other activities such as grazing of domestic animals are permitted as long as these activites do not adversely affect the wild life.
• Examples: • Kaziranga sanctuary (Assam) is for the
protection of rhinoceros, elephants, bison, tigers etc.
• Chilka lake is a bird sanctuary (Orissa) • Periyar sanctuary (Kerala) • Madumalai sanctuary (T.N) • Bandipur sanctuary (Karnataka) is famous
for elephants, deers etc. • Gir forests (Gujarat) is famous for Asiatic
lions
Ex-situ ConservationEx-situ Conservation• It is the conservation of wild life outside their
habitat. • This is achieved by perpetuation of sample
population in genetic resource centres, zoos, botanical gardens, culture collection (tissue culture) or germ-plasma banks.
• Zoos:• Zoos or zoological gardens are places where
wild animals are kept.• The zoos are open to public. The specimens
normally found in zoos are rare, exotic, local, and popular ones. Some specimens are also bred in captivity in zoos
• Botanical gardens:• In botanical gardens rare, endemic and
threatened species of plants are conserved.
• Plants occurring in different ecological conditions are grown in the botanical gardens.
• Botanical garden of Ooty and botanical garden of Calcutta are some examples
• Wild life resources include all animals, which grow and propagate naturally without any sort of human interference.
• They remain in wild form without any sort of friendly association with man. Invariably they are in forests.
• Wildlife serves as a resource to maintain the ecological balance as well as source of entertainment besides acting as source to produce the meat, skins and other animal products.
• The animal species like lion, tiger, cheetah, deer, bear, jackal and number of wild birds are included in wild life wealth.
• Although 'wildlife' refers to any form of life living in its wild (uninterfered) or natural habitat, 'wildlife' in practice means a group of animals living in forests or other natural habitats.
• It usually signifies the animals in wild form without being domesticated.
• Once upon a time, the present day domestic animals like cattle, horse, buffalo, cat, dog were in wild form.
• Wild life resources form important natural resource of a nation. Preserving the wild life is on prioritized agenda of many nations, including India.
• Each species of wild life enjoys specific climate and specific agro ecological situation and therefore more acclimatized to such situation.
• Most of wild animals are confined to specific situation. Their breeding and feeding habits are adjusted to such situations.
• Wildlife includes several hundreds of types of birds, many types of amphibians, reptiles, mammalians and other species
• Other Wild Life Projects In India• 1) Project Tiger• 50 years ago, there were over 40,000
tigers in India.• But poaching and destruction of habitat
had reduced the number to just 1827 by 1972, making them an endangered species.
• To protect the tigers from extinction, the Government of India started "Project Tiger" on April 1st, 1973.
• Due to the success of the project the tiger population has now grown to over 4,000.
• Lion Project• In Gir forest of Gujarat started in 1972. • 3) Yak Research Centre• In Arunachal Pradesh • 4) Crocodile Breeding Project• Started in 1975 • Himalayan Musk Deer Project• At Kedarnath in Uttar Pradesh. • 6) Project Elephant• Started in 1991 • 7) Snow Leopard Project
• At 12 reserves throughout the Himalayas. • 8) Project Hanghul• At Dachigan sanctuary, Jammu and
Kashmir, started in 1970. • 9) Rhino conservation Project at Dudhwal
National Park.• 10) Manipur Brow • Antlered Deer Project at Keibul Lamjoa,
since 1977.
• Endangered and endemic• Due to continuous and constant exploitation by
man, many of the animal species have either become extinct or are at the verge extinction.
• The International Union for Conservation of Nature and Natural resources (IUCN) have printed out five main conservation categories of wild animal and plants:
• Extinct species:• A species is considered extinct when there is no
reasonable doubt that its last individual has died, e.g., mountain quail, pink headed duck, one horned rhino and cheetah
• Endangered species:• Species which are in danger of extinction
and whose survival is unlikely if the causal factors continue to operate.
• e.g., Brow antlered deer, hispid hare, Indian rhinoceros, Great Indian bustard, musk deer, blue whale etc.
• Vulnerable species:• Such a species contains sufficient number of
individuals in its habitat but in the near future, may becme an endangered species if unfavourable conditions persist.
• e.g., crab eating macaque, golden langur, chinkaro deer etc. Rare species:
• Species that are not presently endangered or vulnerable but are at risk e.g., Indian egg eating snake, Indian pied hornbill and golden cat.
• Insufficiently known species:• The species about which there is not enough
information.
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