Ecosystem PDF

ECOSYSTEM Ecology is the study of various ecosystems which is the relationship between organisms and their surroundings (living and non-living). Ecosystem Ecosystem is the basic functional unit of ecology. It is derived from Greek word "study of home". Ecosystem is a group of organi...

ECOSYSTEM Ecology is the study of various ecosystems which is the relationship between organisms and their surroundings (living and non-living). Ecosystem Ecosystem is the basic functional unit of ecology. It is derived from Greek word "study of home". Ecosystem is a group of organisms interacting among themselves and with the environment exchanging its energy and matter. E.g, forest, desert etc. Biome Biome is a small ecosystem within another ecosystem having dominant species with similar lifestyle, climatic conditions and physical structure etc., TYPES OF ECOSYSTEM STRUCTURE OR COMPONENTS OF AN ECOSYSTEM The ecosystem has two major components (a) abiotic and (b) biotic. (a) Abiotic Components Non-living components of ecosystem (physical and chemical) form the abiotic community. (i) Physical components: It includes energy, climate, raw materials and living space.  E.g. Air, water, soil, sunlight (ii) Chemical components: They are the sources of nutrients. (a) Organic substances E.g. proteins, lipids, carbohydrates (b) Inorganic substances E.g. (C, N, O, P, K, H) and (Al, Co, Cu, Zn). (b) Biotic Components Living members in a community form the biotic community. (i) Autotrophic/Producers/Self-feeders: They prepare their own food with the help of chlorophyll, sunlight, water and carbondioxide. E.g. plants, trees. (ii)Heterotrophic / Consumers/ other-feeders: They lack chlorophyll and do not prepare their own food but depends on the producers for their food. (a) Macro consumers: Herbivores, carnivores and omnivores. (b) Micro consumers/ Saprotrophs: Decomposers (bacteria, fungi) Classification/members of biotic components Based on their source of food 1. Autotrophs/ Producers: Prepare their food through photosynthesis using chlorophyll, CO2 and sunlight. 6CO2 + 12H2O C6H12O6+ 6O2 + 6H2O 2. Heterotrophs/Consumers: They do not make their food but depend on producers for their food. (A) Primary consumers/Herbivores. Depend on plants for their food. E.g. Insects, rats. (B) Secondary consumers/Primary carnivores: They feed on primary consumers. E.g. Frogs, cat, snakes. (C) Tertiary consumers/Secondary carnivores: They feed on secondary consumers e.g. lions, tigers Grass Rat Cat Tiger 3. Decomposers: They feed on dead plants and animals and decompose them into simpler compounds releasing inorganic nutrients. These are again utilized by plants with other organic substances for the synthesis of food. e.g. Bacteria, fungi. FUNCTION OF AN ECOSYSTEM  Its main function is to allow the flow of energy and nutrients. Types of function 1. Primary function/ production: It is manufacturing of starch by photosynthesis. 2. Secondary function/ production: It is the distribution of energy to all consumers in the form of food which is stored by them. 3. Tertiary function: The dead systems (plants and animals) are decomposed by decomposers thereby initiating the third function called "cycling". ENERGY FLOW IN THE ECOSYSTEM Solar energy is the main energy on earth‟s surface. About 1% of this is used by plants for photosynthesis. They convert this into chemical energy part of which is used for their growth and remaining is passed onto consumers. Thus, energy enters ecosystem through photosynthesis and travels through different feeding or trophic levels at the rate of 10% and the rest 90% is lost in the form of heat. This indicates that the energy flow is greatly reduced at each trophic levels from producers to carnivores. The energy flow is unidirectional i.e energy from sun never return back to sun. Energy flow through an atmosphere in an ecosystem is governed by laws of thermodynamics I law of thermodynamics - Energy can neither be created nor destroyed, but it can only be converted from one form to another. II law of thermodynamics - Whenever there is transformation of energy, there is loss of energy in the form of heat. The loss of energy takes place through respiration, running, hunting etc. Relationship between structure and function.ECOLOGICAL SUCCE  ECOLOGICAL SUCCeSSION The progressive replacement of one community by another till the development of a stable community in a particular area is called ecological succession. Stages of Ecological succession 1. Pioneer Community: The first group of organisms which establish their community in an area is called pioneer Community. 2. Seres or Seral Stage: The various developmental stages of a community is called 'seres'. Community: Group of plants or animals living in an area. Types of ecological succession 1. Primary succession: Involves gradual establishment of biotic communities on a lifeless ground. 2. (a) Hydrarch: Establishment starts in watery area (lake, pond) 3. (b) Xerarch: Establishment starts in dry land (desert, rocks) 4. Secondary succession: Involves the establishment of biotic communities in an area, where some type of biotic community is already present. Process of ecological succession Ecological succession takes place in the following steps: 1. NUDATION: It is the development of bare land without any life form. 2. INVASION: It is the establishment of one/more species on a bare land through migration followed by establishment. (a) MIGRATION: Migration of seeds by wind, water and birds. Types of food chain 1. Grazing food chain: Found in grass land and pond ecosystems. It starts with green plants and goes to the decomposer/detritus food chain through herbivores and carnivores. 2. Detritus food chain: Found in grassland and forest ecosystems. It starts with dead organic matter and goes to decomposer food chain through herbivores and carnivores.  Trophic levels The various steps through which food energy passes in an ecosystem is called trophic levels. Tl T2 T3 T4 T5 T1 - Green plants/producer T2 - Herbivores/pri mary consumers T3 - Carnivores/seco ndary consumers T4 - Tertiary consumers T5 – Decomposers FOOD WEB Definition: The interlocking pattern of various food chains which are linked together in an ecosystem is called food web. Different types of organisms are connected at different trophic levels so that there are number of opportunities of eating and being eaten at any trophic level. Functions: Maintains the stability of ecosystems. Maintains the nutritional balance in an ecosystem. Control the population size of species in an ecosystem. Provide alternate food source. Energy flow in a food web Significance of food chains and food webs 1. Food webs and food chains play an important role in ecosystem as energy and nutrient flow takes place through them. 2. They maintain and regulate the population size of different trophic levels thereby maintaining ecological balance. 3. They have property of biomagnification. The passing of non- biodegradable material from one trophic level to another causing its concentration to increase and this is called biomagnification. E.g., Biomagnification of DDT The concentration of DDT sprayed on plants increases along the food chain through phytoplankton to zooplanktons and then goes to fish, animals and human beings. Thus concentration of DDT is magnified in birds, animals and humans damaging the egg shells in birds and cell tissues in humans. As DDT is fat soluble its accumulation in human body is easier and cannot be removed easily. ECOLOGICAL PYRAMIDS Definition: The graphical representation of structure and function of trophic levels of an ecosystem is called ecological pyramid. In an ecological pyramid the producers forms the base level and the tertiary consumer occupies the apex level. It represents the number of individual organisms present in each trophic level. e.g., Grassland ecosystem Here, the producers are grasses which are small in size and large in numbers. So, they occupy the lower most level of the pyramid. The primary consumers (rats) occupy the second trophic level as its number is lower compared to that of grass. The secondary consumers (snakes) which are even larger in size and smaller in number form the third level. The tertiary consumers (eagles) occupy the top layer as the numbers of it is the least. 1. Pyramids of energy  It represents the amount of energy present in each trophic level. At every successive tropic level there is a heavy loss of energy (about 90%) in the form of heat. Thus at each next higher tropic level only 10% of energy is transferred. 2. Pyramids of energy It represents the total amount of biomass (mass or weight of biological material or organism) present in each trophic level. e.g., Forest ecosystem The trees in forest ecosystem are the producers and they are maximum in number contributing to a huge biomass. The next tropic levels are the herbivores (insects, birds) and then carnivores (snakes, foxes). The topmost level is the tertiary consumers (tiger, lion) which are few and hence having low biomass. FOREST ECOSYTEM Forest consists of densely growing trees which cover 40% of world's land and 19% of Indian land. Types of forests and their features Depending on the climatic conditions forests are classified into the following types: (a) Tropical rain forest: They are found near the equator. They are characterized by high temperature. Trees like teak and sandal and animals like lion and tiger are found in these forests. (b) Tropical deciduous forest: They are found a little away from equator. They have warm climate and rain only during monsoon. Trees like maple, oak and animals like deer and fox are found in these forests. (c) Tropical shrub forest: They have dry climate for long time. Have small deciduous trees and shrubs and animals like deer, fox, etc. (d) Temperate rain forest: They are found in temperate areas with adequate rain.Coniferous trees like fir, pines and animals like squirrels, fox are found here. (e) Temperate deciduous forest: These are found in areas with moderate temperatures. Trees like oak, hickory and animals like deer, fox are found in these forests. Characteristics of forests ecosystem 1. They have warm climate and adequate rainfall, which generates number of ponds, lakes etc. 2. Forests maintain rainfall and climate. 3. Forests support many wild animals and protect biodiversity. 4. Soil is rich in nutrients and organic matter which support the growth of trees. 5. As sunlight penetration is poor, conversion of organic matter into nutrients is very fast. Structure and function of forest ecosystem 1. Abiotic components: e.g., Temperature, light, rain and minerals. They are the inorganic and organic substances found in soil and atmosphere. 2. Biotic components: (a) Producers: Trees, shrubs (b) Consumers: (i) Primary consumers: Insects (ii) Secondary consumers: Birds, snakes (iii) Tertiary consumers: Tiger, lion (c) Decomposers: Bacteria, fungi. Rate of decomposition of dead matter in tropical and subtropical forest is more than in temperate forest. GRASSLAND ECOSYSTEM Grasslands are large areas of grass with scattered trees which occupies about 20% of world's land. 1.19.1 Types and features of grasslands 1. Tropical Grassland: they are found near borders of tropical rain forests. They have high temperature and moderate rainfall (40 to 100cm). They are also called Savanna-type. They have tall grasses and shrubs and animals like zebra, giraffe. 2. Temperate grassland: They are found in centres of continents, on flat, sloped hills. They have cold winters and hot summers. Intense grazing and summer fires do not allow shrubs or trees to grow in this grassland. 3. Polar grassland: They are found in arctic polar region and have severe cold and strong wind with snow and ice. In summers several annual plants grow and animals like arctic wolf, arctic fox is found here. Characteristics of grassland ecosystem 1. Grassland ecosystem is plain land occupied by grasses. 2. Soil is rich in nutrients and organic matter. 3. Since there are tall grasses, it is an ideal place for grazing animals. 4. It is characterized by low or even rainfall. Structure and function of grassland ecosystem 1. Abiotic components: e.g., Nutrients (C, H, O ,N ,P , S) supplied by CO2, H2O, nitrates, phosphates and sulphates. 2. Biotic components: (a) Producers: Grasses, shrubs (b) Consumers: (i) Primary consumers: Cows, deer (ii) Secondary consumers: Snakes, lizards (iii) Tertiary consumers: Eagles (c) Decomposers: Fungi and bacteria. DESERT ECOSYSTEM Deserts occupy about 35% of world's land. The atmosphere is dry and hence a poor insulator. Types and features of desert 1. Tropical desert: They are found in (i) Africa: Sahara desert (ii) India: Thar desert They have few species and wind-blown sand dunes are common. 2. Temperate desert: They are found in South California: Majave desert They have very hot summer and very cool winter. 3. Cold desert: They are found in China: Gobi desert They have cold winters and warm summers. Characteristic features of desert ecosystem 1. The desert air is dry and climate is hot. 2. Annual rainfall is less than 25cm. 3. The soil is poor in nutrients and organic matter. 4. Vegetation is poor. Structure and function of desert ecosystem 1. Abiotic components: Temperature, rainfall, sunlight The temperature is very high and rainfall and nutrient cycling are very low. 2. Biotic components: (a) Producers: Shrubs, bushes, some grass In desert there are succulent plants like cacti which have water inside them and waxy outer coating to protect form sun. (b) Consumers: Squirrels, mice, reptiles. These animals dig holes in the ground to live and come out at night for food. Most of the desert animals can extract water from seeds. (c) Decomposers: Fungi and bacteria Desert has poor vegetation with low amount of dead organic matter. They are decomposed by few bacteria and fungi. AQUATIC ECOSYSTEM This deals with water bodies. The major types of organisms found in aquatic environments are determined by water salinity. Types of aquatic ecosystems: Based on the salinity it is classified into 2 types as (i) Fresh water ecosystem: Ponds, lakes, rivers, streams (ii) Marine/ salt water ecosystem: Oceans, estuaries 1. Fresh water ecosystem: POND ECOSYSTEM Characteristic features of pond ecosystem 1. Pond is temporary, only seasonal. 2. It is stagnant fresh water body. 3. Pond gets polluted easily due to limited amount of water. Structure and Function of Pond ecosystem 1. Abiotic components: Temperature, light, water, organic and inorganic compounds. 2. Biotic components: (a) Producers: They are of 2 types (i) Phytoplankton: These are microscopic aquatic plants, which freely float on the water surface. e.g., Algae, pandorina. (ii) Microphytes: These are large floating plants and submerged plants. e.g., Hydrilla, wolfia. (b) Consumers: (i) Primary consumers (Zooplanktons): These are microscopic animals which float freely on the water surface. e.g., Protozoa, very small fish, ciliates. Zooplanktons are found along with phytoplankton sans they feed on them. (ii) Secondary consumers (Carnivores): Insects like water beetles and small fish. (iii) Tertiary consumers: Large fish like game fish. (c) Decomposers: Fungi, bacteria, flagellates. LAKE ECOSYSTEM Lakes are supplied water by rainfall, melting snow and streams. Types of lakes 1. Oligotrophic lakes: They have low nutrient concentrations. 2. Eutrophic lakes: They are over nourished by nutrients like N and P. 3. Dystrophic lakes: They have low pH, high humic content and brown waters. 4. Volcanic lakes: They receive water from magma after volcanic eruptions. 5. Meromictic lakes: They are rich in salts. 6. Artificial lakes: They are created due to construction of dams. Zones of lake Depending upon their distance from the shore, a lake consists of 4 distinct zones. 1. Littoral zone: It is the top layer of the lake. It has shallow water. 2. Limnetic zone: It lies below the littoral zone, where effective penetration of sunlight takes place. 3. Profundal zone: This is the deep open water, where it is too dark. 4. Benthic zone: This layer is the bottommost layer of the lake. Characteristic feature of lake ecosystem 1. Lake is shallow fresh water body. 2. It is a permanent water body with large water resources. 3. It is useful for irrigation and drinking purpose. Structure and function of Lake Ecosystem 1. Abiotic components: Temperature, light, proteins and lipids.  2. Biotic components: (a) Producers: These are the green plants which may be submerged, free floating and amphibious plants. e.g., Phytoplankton, algae (b) Consumers: (i) Primary consumers (Zooplankton): Ciliates, protozoans. (ii) Secondary consumers (Carnivores): Insects and small fishes. (iii) Tertiary consumers: Large fish like game fish. (c) Decomposers: Bacteria and fungi RIVER/STREAM ECOSYSTEM The running water of a river or stream is well oxygenated, because it absorbs oxygen from air. The numbers of animals are low in river or stream. Characteristic features of river or stream ecosystem 1. It is fresh water and free flowing water system. 2. Due to mixing of water, dissolved oxygen content is more. 3. River deposits large amount of nutrients. Structure and function of river ecosystem 1. Abiotic components: Temperature, light, pH, nutrients. 2. Biotic components: (a) Producers: Phytoplankton, algae, water grasses. (b) Consumers: (i) Primary consumers: Water insects, snails (ii) Secondary consumers: Birds and mammals (c) Decomposers: Bacteria, fungi MARINE/OCEAN ECOSYSTEM Oceans cover more than two thirds of earth's surface. It supplies a vast variety of sea products and drugs. It has high concentration of salts and minerals. Zones of Oceans The oceans have two major life zones. (i) Coastal zone: It is relatively nutrient rich, shallow water and has high productivity because of high nutrients and sunlight. (ii) Open sea: It is the deeper part of the ocean and is vertically divided into 3 regions. (a) Euphotic zone: It receives abundant light and shows high photosynthetric activity. (b) Bathyal zone: It receives dim light and is geologically active. (c) Abyssal zone: It is the dark zone and is very deep (2000 to 5000 m).  Characteristic features of marine ecosystem 1. It occupies a large surface area with saline water. 2. Since, ships, submarines can sail in ocean a large number of commercial activities are carried out. 3. It is rich in biodiversity. 4. It moderates the temperature of earth. Structure and function of marine ecosystem 1. Abiotic components: Temperature, light, NaCl, KCl. 2. Biotic components: (a) Producers: Phytoplankton and marine plants (b) Consumers: (i) Primary consumers (Herbivores): Crustaceans, molluscs (ii) Secondary consumers (Carnivores): Herring, mackerel (iii) Tertiary consumers: Cod (c) Decomposers: Bacteria, fungi. ESTUARINE ECOSYSTEM "An estuary is a partially enclosed coastal area at the mouth of a river which joins the sea". They are rich in nutrients and have high food potential. Characteristics of estuarine ecosystem 1. Estuaries are transition zones, which are strongly affected by tides of sea. 2. Water characteristics are periodically changed. 3. The living organisms here have wide tolerance. 4. Salinity in estuaries are highest in summer and lowest in winter. Structure and function of estuarine ecosystem 1. Abiotic components: Temperature, pH, sodium and potassium salts. 2. Biotic components:  (a) Producers: Marsh grasses, sea weeds, sea grasses. (b) Consumers: Oysters, Crabs, small fishes. (c) Decomposers: Bacteria, fungi. KEYSTONE SPECIES Within a habitat each species connects to and depends on other species. But, while each species contribute to habitat functioning, some species do more than others in the overall scheme of things. Without the work of these key species, the habitat changes significantly. These species are called “keystone species". When a keystone species disappears from its habitat, that habitat changes dramatically. Illustration - 1 Elephants as keystone species in Grasslands Elephants are keystone species in African grasslands. When elephants are taken away from grasslands, it is converted into forest or shrub areas by overgrowth of woody plants. As keystone species, elephants prevent this conversion. Illustration - 2 Forest elephants hold keystone status in some woodland (forest) in western Africa In the above forest elephants are the only species large enough to eat and disperse the seeds of some plant species whose shells are very hard. Thus only elephants can feed on them and disperse the seeds through their dung thereby maintains the forest. Introduction to biodiversity definition: genetic, species and ecosystem diversity: BIODIVERSITY DEFINITION: Bio means „life‟ and diversity means „variety‟, hence Biodiversity refers to variety of life on the earth. Planet earth (biosphere) contains more than 20 million species of organisms. They differ widely from one another. Diversification in the species is influenced by various physical and climatic factors, resulting in the production of new sub-species. Biodiversity is defined as, “the variety and variability among all groups of living organisms and the ecosystem in which they occur”. LEVELS OF BIODIVERSITY: A. GENETIC BIODIVERSITY The genes found in organisms can form enormous number of combinations each of which gives rise to some variability. When the genes within the same species show different version due to new combinations, it is called genetic variability. For example rice belongs to the species Oryzasativa which has many varieties that differ in size, shape, aroma etc. B. SPECIES BIODIVERSITY This is the variability found within the population of a species or between different species of a community. It broadly represents the species richness and their abundance in a community. Shannon Wiener index and Simpson index are two popular indices of measuring species diversity. C. ECOSYSTEM BIODIVERSITY This is the diversity of ecological complexity showing variations in ecological niche, trophic structure, food webs, nutrient cycling etc. The ecosystem also shows variations with respect to physical parameters like moisture, temperature, altitude, precipitation etc. BIOGEOGRAPHICAL CLASSIFICATION OF INDIA: Biogeographic zone Biotic province Important Flora & Fauna Trans-Himalayan Upper region Pine,deodar- Wild sheep, yak, leopard, wolf Himalayan North west, west, Pine, cork tree, sal, dhaak- Wild bear, central and East sambar, leopard, Sikkim stag, musk deer Himalayas Desert Kutch, Thar and Acacia, zizyphus, khejri, date palm- Ladkh Camel, bastard, wild ass, desert cat, fox, rat Semi-arid Central India, Acacia, date palm, peepal -Gir lion, tiger, Gujarat sariska and Ranthampore tiger Western ghats Malabar coast Sheeshan, peepal, tuna, bahera- Tortoise, Western ghats frog, lizards, snakes mountain Deccan peninsula Deccan plateau Acacia, palaash, tuna, pine, castor- Sambar, sloth bear, tiger, cheetal, four horned stag, wild elephant, wild buffalo Gangetic plain Upper and lower Sal, acacia, jamun, mango, bael- Gangetic plain black chinkara, stag, rhinoceros, gazzel, Aligator, turtle North-east India Brahmaputra Bamboo, sal, jack fruit, tuna, Chestnut valley cator- Elephnat, Rhinocers, yak, deer, porcupine Islands Andaman islands, Bahera, Harar, jack fruit, cardamom, Nicobar islands & coconut, cloves- Dolphin, alligator, Lakshadeep Molluscs islands Coasts West coast Coconut, Banana, cashew Nut – Dugong, East coast Dolphin, Turtle, Alligator, Molluscs VALUE OF BIODIVERSITY: (Consumptive use, Productive use, Social, Ethical, Aesthetic and Option values) 1. CONSUMPTIVE USE VALUE Food: A large number of wild plants are consumed by human beings as food. About 80,000 plants are from wild. About 90% of crops are domesticated from tropical forest. Drugs and medicine: About 75% of population depends upon plant or plant extracts for medicine. Penicillin antibiotic drug is derived from the fungus penicillium. Fuel: The fossil fuels coal, petroleum and natural gas are products of fossilized biodiversity. 2. PRODUCTIVE USE VALUE These are the commercially usable values where the product is marketed and sold. It may include lumber or wild gene resources that can be traded for use by scientist for introducing desirable traits in the crops and domesticated animals. It includes animal products like tusk of elephants, musk deer, silk from silk worm, wool from sheep, fur of many animals etc. Many industries like paper and pulp. Silk, textile, ivory works industry depend on them. 3. SOCIAL VALUE It is associated with social life, customs, and religion and psycho-spiritual aspects of the people. Many plants are considered holy and sacred in our country like tulsi, peepal, Mango, Lotus, Bael etc. many animals like cow, snake, peacock, bull, owl etc also have significant place in social importance. The tribal people are very closely linked with the wildlife in the forest. 4. ETHICAL VALUE It is otherwise called existence value. It involves ethical issues like “all life must be preserved” and “live and let live” concept. For the survival of human race, all biodiversity has to be protected because biodiversity is valuable. 5. AESTHETIC VALUE People from far and wide spend a lot of time and money to visit wilderness areas where they can enjoy the aesthetic value of biodiversity and this type of tourism is known as eco –tourism. The willingness to pay concept annually generates 12 billion revenue. 6. OPTION VALUE It is the value of knowing that there are biological resources existing on the biosphere that may one day prove to be an effective option for something important in the future it suggests that any species may prove to be miracle species someday. BIODIVERSITY AT GLOBAL, NATIONAL AND LOCAL LEVEL: BIODIVERSITY AT GLOBAL LEVEL: It is estimated that there are about 20 million species of plants and animals in earth of which only 1.6 million species have been formally identified with 34 hotspot regions at the global level. There are 12 megadiversity nations which are highly rich in biodiversity which includes India. Most of the world‟s biodiversity are near the equator especially tropical rain forests and coral reefs. South America also has unique species and biodiversity. BIODIVERSITY AT NATIONAL LEVEL: India is rich in biodiversity due to its varying climate and topographical features. It occupies only 2.5% of global land of which about 40% is under cultivation. There are 96 national parks, 572 wildlife sanctuaries 14 biosphere reserves and 2 hotspots with 46,000 plant species and 91,000 animal species, 50,000 varieties of rice, 1000 varities of mango, etc., 1. India ranks 10th among the plant rich countries of the world 2. 11th in terms of Endemic species. 3. 6th among origin of agricultural crops. 4. 12th mega biodiversity country in the world. BIODIVERSITY AT REGIONAL OR LOCAL LEVEL: Tamilnadu is rich in biodiversity with natural habitat constituting 4% of country‟s total area which shares the Western Ghats with Kerala, Karnataka, Maharashtra, Goa and, Eastern Ghats with Andhra Pradesh and Odisha accounting for nearly about one third of the total flora of India. 1. Point Richness: Refers to number of species at a single point. 2. Alpha Richness: Refers to the number of species found in a small homogeneous area. 3. Beta Richness: Refers to rate of change in species composition across different habitats. 4. Gamma Richness: Refers to the rate of change across large landscape gradients. INDIA AS A MEGA BIODIVERSITY NATION: India is one of the 12 mega biodiversity countries in the world. The Ministry of environmental and forests, Government of India (2000) records 47,000 species of plants and 81,000 species of animals which is about 7% and 6.5% respectively of global flora and fauna. 1. Endemism: Species which are restricted to only to a particular area are known as endemic. India shows a good number of endemic species. About 62% of amphibians and 50% of lizards are endemic. 2. Centre of origin: A large number of species have known to originate in India. Nearly 5000 flowering species, 166 species of crop plants and 320 species of wild relatives of cultivated crops origin in India. 3. Marine diversity: Along 7500 km long coastline of our country in the mangroves, estuaries, coral reefs, back waters etc. there exist a rich biodiversity. More than 340 species of corals of the world are found here. HOTSPOTS OF BIODIVERSITY A biodiversity hotspot is a biogeographic region with a significant reservoir of biodiversity that is under threat from humans. To qualify as a biodiversity hotspot on Myers 2000 edition of the hotspot- map, a region must meet two strict criteria: 1. It must contain at least 0.5% or 1,500 species of vascular plants as endemics. 2. It must have lost at least 70% of its primary vegetation. Around the world, at least 25 areas qualify under this definition, with nine others possible candidates. These sites support nearly 60% of the world's plant, bird, mammal, reptile, and amphibian species, with a very high share of endemic species. The importance of biodiversity: Biodiversity is often used to draw attention to issues related to the environment. It can be closely related to: The health of ecosystems. For example, the loss of just one species can have different effects ranging from the disappearance of the species to complete collapse of the ecosystem itself. This is due to every species having a certain role within an ecosystem and being interlinked with other species. The health of mankind. Experiencing nature is of great importance to humans and teaches us different values. It is good to take a walk in the forest, to smell flowers and breathe fresh air. More specifically, natural food and medicine can be linked to biodiversity.  Hot spots of Biodiversity in India: The hot spots of biodiversity are the geographic areas which possess the high endemic species. At the global level these are the areas of high conservation priority, if these species are lost they can never be replaced or regenerated. Criteria for recognizing Hotspots: The richness of the endemic species is the primary criterion; they should have a significant percentage of specialized species; the site should be under threat and should contain important gene pools of plants of potential use. Two hot spots in India are: 1. Eastern Himalayas (Indo-Burma region) and 2. Western Ghats (Srilanka region). Eastern Himalayas: Comprises of Nepal, Bhutan and neighboring states of Northern India- 35,000 plant species are found here and 30 % are endemic – also rich in wild plants of economic value eg. Rice, banana, citrus, ginger, chilli, jute and sugarcane – Taxal yielding plant also scarcely distributed – 63% mammals are from this region- 60% of Indian Birds- huge wealth of fungi, insects, mammals and birds found in this region Western Ghats: Comprises of parts of Maharashtra, Karnataka, Tamilnadu and Kerala – nearly 1500 endemic, dicotyledones 62% amphibians and 50% lizards are endemic here- Ternstroemia, Japonica, Rhododendron and Hypericum common plants- Blue Bird and Lizard hawk are common animals. Biodiversity is the richness & varied species of different organisms contained in a particular ecosystem – Indian biodiversity is highly diverse and rich such that there are various hot spots. However there are numerous threats to our Biodiversity. THREATS TO BIODIVERSITY :( Habitat loss, Poaching of wildlife & Man- wildlife conflicts) In 2006 many species were formally classified as rare or endangered or threatened; moreover, scientists have estimated that millions more species are at risk which has not been formally recognized. About 40 percent of the 40,177 species assessed using the IUCN Red List criteria are now listed as threatened with extinction.  LOSS OF HABITAT: Habitat destruction: Habitat destruction has played a key role in extinctions, especially related to tropical forest destruction. Factors contributing to habitat loss are: overpopulation, deforestation, pollution (air pollution, water pollution, soil contamination) and global warming or climate change. Habitat size and numbers of species are systematically related. Physically larger species and those living at lower latitudes or in forests or oceans are more sensitive to reduction in habitat area. Climate change: Global warming is also considered to be a major potential threat to global biodiversity in the future. Climate change has seen many claims about potential to affect biodiversity but evidence supporting the statement is tenuous. Increasing atmospheric carbon dioxide certainly affects plant morphology and is acidifying oceans, and temperature affects species ranges, phenology, and weather, but the major impacts that have been predicted are still just potential impacts. We have not documented major extinctions yet, even as climate change drastically alters the biology of many species. POACHING: Illegal trade of wildlife products by killing prohibited endangered animals i.e. poaching is another threat to wildlife. Despite international ban on trade in products from endangered species, smuggling of wildlife items like furs, hides, horns, tusks, live specimens and herbal products worth millions of dollars per year continues. The developing nations in Asia, Latin America and Africa are the richest source of biodiversity and have enormous wealth in wildlife. Overexploitation: Overexploitation occurs when a resource is consumed at an unsustainable rate. This occurs on land in the form of overhunting, excessive logging, poor soil conservation in agriculture and the illegal wildlife trade Joe Walston, director of the Wildlife Conservation Society's Asian programs, called the latter the "single largest threat" to biodiversity in Asia. The international trade of endangered species is second in size only to drug trafficking. MAN-WILDLIFE CONFLICTS: CAUSES OF MAN WILDLIFE CONFLICT:  1. Dwindling habitats of elephants, Tigers, rhinos and bears due to forest shrinkage compels them to move outside forest. 2. Usually ill, weak, and injured animals have a tendency to attack the humans. 3. Earlier Forest department used to cultivate paddy, sugarcane within the sanctuaries, due to lack of such practices the animals move out of forest food. 4. Villagers put Electric Wiring around their crop field which injures the elephants and turn them violent. 5. Wildlife corridors have been disrupted which makes the animals attack human beings during their migration. REMEDIAL MEASURES TO CURB THE CONFLICT: 1. Tiger conservation Project (TCP) has made provisions for making available vehicles, tranquillizer guns, binoculars and radio sets etc., to tactfully deal with any imminent danger. 2. Adequate crop compensation and cattle compensation scheme must be started. 3. Solar powered fencing should be provided to prevent animals from 4. straying into fields. 5. Cropping pattern should be changed near the border. 6. Wildlife corridors should be provided. Introduced and invasive species: Barriers such as large rivers, seas, oceans, mountains and deserts encourage diversity by enabling independent evolution on either side of the barrier, via the process of allopatric speciation. The term invasive species is applied to species that breach the natural barriers that would normally keep them constrained. Without barriers, such species occupy new territory, often supplanting native species by occupying their niches, or by using resources that would normally sustain native species. Genetic pollution: Endemic species can be threatened with extinction through the process of genetic pollution, i.e. uncontrolled hybridization, introgression and genetic swamping. Genetic pollution leads to homogenization or replacement of local genomes as a result of either a numerical and/or fitness advantage of an introduced species. Hybridization and introgression are side-effects of introduction and invasion. Hybridization, genetic pollution/Erosion and food security In agriculture and animal husbandry, the Green Revolution popularized the use of conventional hybridization to increase yield. Often hybridized breeds originated in developed countries and were further hybridized with local varieties in the developing world to create high yield strains resistant to local climate and diseases. Local governments and industry have been pushing hybridization. Formerly huge gene pools of various wild and indigenous breeds have collapsed causing widespread genetic erosion and genetic pollution. This has resulted in loss of genetic diversity and biodiversity as a whole. ENDANGERED AND ENDEMIC SPECIES OF INDIA: 1. ENDANGERED SPECIES OFINDIA The international Union for conservation of Nature and Natural Resources (IUCN) publishes the red Data book which includes the list of endangered species of plants and animals. Species Names Reptiles Gharial, green sea turtle, tortoise,python Birds Great Indian bustard, Peacock, Pelican, Great Indian hornbill, Siberian White crane Carniv Indian Wolf, red fox, sloth bear, red panda, tiger, leopard, ors Stripped Hyena, Indian lion, Golden cat, desert cat, Dugong Mamm als Primates Hoolock Gibbon, lion tailed Macaque, Nilgiri languor, capped monkey, Golden monkey Plants A large number of species of Orchids, Rhododendrons, Medicinal Plants like Rauvolfia serpentine, the sandal wood tree santalum, Cycasbeddonei 2. ENDEMIC SPECIES OFINDIA: India has two biodiversity hotspots and thus possesses a large number of endemic species. Out of about 47,000 species of plants in our country 7000 species are endemic. Thus, Indian subcontinent has about 62% endemic flora, restricted mainly to Himalayas, Khasi Hills and WesternGhats. Some of the endemic flora includes orchids and species like Sapria Himalaya, Uvarialurdia A large number out of total 81,000 species of animals in our country is endemic. The Western Ghats are particularly rich in amphibians and reptiles. About 62% Amphibians and 50% lizards are endemic to Western Ghats. Different species of Monitor lizards, reticulated python and Indian salamander and viviparous toad are some important endemic species of our country. CONSERVATION OF BIODIVERSITY (In-situ conservation & Ex-situ conservation) In-situ and ex-situ conservation along with their merits and limitations: Conservation of Biodiversity: Biodiversity faces threat of extinction – due human activities – to salvage situation – conservation of biodiversity need of the hour- to preserve biodiversity to prevent their extinction and future flourishing – conservation of Biodiversity required In-situ conservation: Involves allocating large areas of the land mass for wild life development- such areas can be closed to the public for tourism – wild life can be allowed to flourish in their own environment- promotes genetic diversity- does not stagnate the gene pool Advantages: cheap and convenient method Species gets adjusted the natural disasters like drought, floods, forest fires. Limitations: Large surface area of the earth required – shortage of staff and pollution may lead to improper maintenance of the habitat. Ex-situ conservation: Involves conservation of wild life in zoos, botanical gardens-human supervision- wildlife can grow under controlled conditions - animals would be properly taken care- food, shelter and water- help in the flourishing of endangered species- possible the gene pool could stagnate and result in no genetic diversity taking place. Advantages: Special care and attention lead to survival of endangered species– In captive breeding, animals are assured food, water, shelter and security - hence longer life span- it is carried out for the endangered species, which do not have any chances of survival in the wild. Limitations: Expensive method- freedom of wild life is lost – animals cannot survive in such confined places.