Biodiversity and Conservation PDF

NOTES Biodiversity and Conservation © 2022, Aakash BYJU'S. All rights reserved Key Takeaways Biodiversity 1 Genetic biodiversity Species biodiversity Ecological biodiversity 2 Patterns of biodiversity Latitudinal gradient Species-Area Relationship Loss of biodiversity © 2022, Aakash BYJU'S. All righ...

NOTES Biodiversity and Conservation © 2022, Aakash BYJU'S. All rights reserved Key Takeaways Biodiversity 1 Genetic biodiversity Species biodiversity Ecological biodiversity 2 Patterns of biodiversity Latitudinal gradient Species-Area Relationship Loss of biodiversity © 2022, Aakash BYJU'S. All rights reserved 3 Key Takeaways 4 Causes of biodiversity loss 5 6 Red book and IUCN Biodiversity conservation 9 10 Summary © 2022, Aakash BYJU'S. All rights reserved Susceptibility to extinction 7 8 Strategies to conserve biodiversity Result of biodiversity loss Conventions on biodiversity Biodiversity Biodiversity is the total number of species of plants, animals and microorganisms living on the earth.  Biodiversity is not uniform, as it is tremendous in some places, moderate in others and low in certain regions.  In the world, there are : ○ around 28,000 species of fishes ○ more than 20,000 species of ants ○ 3,00,000 species of beetles ○ nearly 20,000 species of orchids © 2022, Aakash BYJU'S. All rights reserved Biodiversity  Edward O. Wilson is the sociobiologist, who popularized the term biodiversity.  He is regarded as the father of biodiversity.  He described the combined biodiversity (or heterogeneity) at all the levels of biological organisation from macromolecules within the cells, genes, species, ecosystems and biomes. Genetic diversity Levels of biodiversity Species diversity Ecological diversity © 2022, Aakash BYJU'S. All rights reserved Genetic Diversity Genetic diversity is a measure of variety in genetic information contained in the organisms.  It enables a population to adapt to its environment and changes occurring around. Example : o Rauwolfia vomitoria, a medicinal plant. o It produces a chemical called reserpine. o The potency and concentration of reserpine produced varies for different members of this species growing in different Himalayan ranges. © 2022, Aakash BYJU'S. All rights reserved Fruits Rauwolfia vomitoria Genetic Diversity Other examples found in India: More than 50,000 genetically different strains of rice 1,000 varieties of mango due to genetic variation This genetic variation helps in formation of ecotype and plays important role in process of speciation. © 2022, Aakash BYJU'S. All rights reserved Species Diversity Species diversity refers to the variety of species within a region. For example : Western Ghats have greater diversity of amphibians than Eastern Ghats  It is a product of species richness and species evenness Species diversity  Species richness = Number of species / area  Species evenness = Proportionate number of individuals of different species  Maximum taxonomic diversity = Species of taxonomically different groups occur in almost equal abundance © 2022, Aakash BYJU'S. All rights reserved Genetic diversity Species Diversity : Globally  According to the International Union Conservation of Nature and Natural Resources (IUCN 2004) o Total number of plant and animal species = more than 1.5 million  According to Robert May, o Number of global species diversity = about 7 million More than 70% Nearly 22% Number of animal species Plant (includes algae, fungi, bryophytes, gymnosperms and angiosperms Earth’s biodiversity based on the current available species data © 2022, Aakash BYJU'S. All rights reserved Species Diversity : India India has 45,000 species of plants. India has nearly 90,000 species of animals. India has 2.4 % of world’s land area. India contributes 8.1 % to global species diversity.  India is one of the 12 mega diversity countries of the worlds.  India is divided into 10 biogeographical regions. © 2022, Aakash BYJU'S. All rights reserved Ecological Diversity Ecological diversity refers to the variety of ecosystem. Indicates diversity in : Number of species Trophic levels Food webs © 2022, Aakash BYJU'S. All rights reserved Ecological diversity Nutrient cycles Ecological processes Species diversity Genetic diversity Ecological Diversity  For example: o Ecosystem diversity is high in India because of the occurrence of a large number of ecosystems like deserts, rainforests, mangroves, coral reefs, wetlands, estuaries and alpine meadows in comparison to small countries such as Norway. Types of ecological diversity © 2022, Aakash BYJU'S. All rights reserved Alpha diversity of a community Beta diversity between community Gamma diversity of a region Patterns of Biodiversity  The diversity of plants and animals is not uniform with uneven distribution  There are many interesting patterns in diversity like o latitudinal gradient o altitudinal gradient o geographical gradient o topographical gradient o humidity gradient The two most accepted and famous concepts of patterns of biodiversity are : Latitudinal gradient © 2022, Aakash BYJU'S. All rights reserved Species area relationship Latitudinal Gradient  The biodiversity decreases from the equator to the poles. Minimum Moderate Maximum Biodiversity Artic region Temperate region Tropical region Temperate region Antarctic region © 2022, Aakash BYJU'S. All rights reserved Latitudinal Gradient Examples of high diversity in tropical regions ( 23.5 °N to 23.5° S):  India has more than 1,200 species of birds because the covered land falls in the tropical region.  A forest in a tropical region like Ecuador has up to 10 times as many species of vascular plants as a forest of equal area in a temperate region, like the Midwest of the USA. © 2022, Aakash BYJU'S. All rights reserved Country Region No. of bird species Columbia Tropical region 1,400 New York Temperate region 105 Greenland Arctic region 56 Latitudinal Gradient  The tropical Amazonian rain forest in South America has the greatest biodiversity on Earth.  In these rain forests, there might be at least two million insect species yet to be discovered and named. © 2022, Aakash BYJU'S. All rights reserved Taxa No. of species Plants More than 40,000 Mammals 427 Birds 1,300 Reptiles 378 Amphibians 427 Fishes 3,000 Invertebrates More than 1,25,000 Latitudinal Gradient Cause of high diversity in tropical regions : 1. Tropical areas receive more solar energy. Thus, its communities are more productive which supports wider range of species. Artic region Sunlight Temperate region Plant Tropical region Animal Temperate region Antarctic region © 2022, Aakash BYJU'S. All rights reserved Tropical region Latitudinal Gradient 2.   Favourable conditions in tropical regions are due to o warm temperatures o humidity Therefore, these regions are o less seasonal o relatively more constant o predictable This helps tropical organisms to gain more niche speciation and leads to greater species diversity. © 2022, Aakash BYJU'S. All rights reserved 3. Speciation is a function of time.  Due to frequent glaciations in temperate areas, many species were killed.  However, in tropical region, diversification occurred due to stable conditions.  Due to stability, tropical species continued to flourish and evolved undisturbed for millions of years. Species - Area Relationship  Alexander von Humboldt explored South American jungles and found that within a region, species richness increases with increase in area but only up to a limit  Relationship between species richness and area = Rectangular hyperbola Significance of slope regression / regression coefficient (Z): The relationship indicates that, S∝A  For small area, Z = 0.1 to 0.2 S = species richness A = area Z = slope of the line (regression coefficient) C = Y-intercept © 2022, Aakash BYJU'S. All rights reserved  For larger area, slope of line is much steeper than smaller area, Z = 0.6 to 1.2 Importance of Species Diversity  Variety of species in a community plays an important role in the functioning of the ecosystem  Rich biodiversity is important for stability, productivity, resilience, alternative pathways and health of ecosystem 1. Stability : o Stable community should not show too much variation in productivity from year to year. o It must be either resistant or resilient to occasional disturbances (natural or man-made). o It must also be resistant to invasions by alien species. o Communities with more species = more stable. © 2022, Aakash BYJU'S. All rights reserved Importance of Species Diversity  David Tilman’s worked on longterm ecosystem experiments. Different species  He studied connectivity between community stability and species richness by using outdoor plots.  He confirmed that o plots with more species showed less year-to-year variation in total biomass. o increased diversity contributed to higher productivity. © 2022, Aakash BYJU'S. All rights reserved (A) More species diversity More stable community (B) Less species diversity Less stable community Importance of Species Diversity 2. Ecosystem health : Rivets o Rich biodiversity is not only essential for ecosystem health, but also for survival of human race on earth. o Because larger number of species, have high number of niches, more interactions and more interrelationships. Wings Wings  Paul Ehrlich, Stanford ecologist, gave a proper perspective through an analogy the ‘rivet popper hypothesis’  In his analogy, o airplane = ecosystem o rivets = species © 2022, Aakash BYJU'S. All rights reserved Rivet Popper Hypothesis  In an airplane (ecosystem), all parts are joined together using thousands of rivets (species).  If a rivet pops out (causing species to extinct), this may not affect flight safety (proper functioning of the ecosystem) initially.  However, as more and more rivets are removed, the plane becomes dangerously weak over a period of time.  Loss of rivets on the wings (key species that drive major ecosystem functions) is more serious threat to flight safety than loss of a few rivets. Species which plays a very critical and pivotal role in the functioning and stability of the entire ecosystem are called keystone species. E.g., Tiger, shark, vulture etc. © 2022, Aakash BYJU'S. All rights reserved Loss of Biodiversity  The biological wealth of our planet has been declining rapidly.  Complete disappearance or extinction of a species results in complete loss of genetic information contained in it. Natural extinction Due to change in environmental conditions, species disappeared in the geological past at a very slow rate, which is known as natural extinction. Mass extinction It is dying off or extermination of a large number of species due to catastrophes. Five episodes of mass extinction of species has occurred. © 2022, Aakash BYJU'S. All rights reserved Loss of Biodiversity Anthropogenic extinction It is extermination of species caused directly or indirectly by human activities like habitat destruction, over-exploitation, hunting, pollution etc.  Colonisation of tropical Pacific Islands by humans have resulted in extinction of more than 2,000 species of native birds. © 2022, Aakash BYJU'S. All rights reserved Loss of Biodiversity IUCN Red list documents the extinction of species  Some examples include: IUCN Red List (2004) 338 vertebrates 87 plants Dodo (Mauritius) Steller’s Sea Cow(Russia) Quagga (Africa) Thylacine (Australia) 359 invertebrates Caspian tiger 784 species have become extinct, in last 500 years © 2022, Aakash BYJU'S. All rights reserved Javan tiger Bali tiger 27 species have become extinct, in last 20 years Loss of Biodiversity  Extinctions across taxa are not random.  Some groups like amphibians appear to be more vulnerable to extinction.  Global threat of extinction = 15,500 species 12% of bird species 23% of mammal species 31% of gymnosperm species 32% of all amphibian species Global species : Threat to extinction © 2022, Aakash BYJU'S. All rights reserved Loss of Biodiversity  Anthropogenic extinction will cause the 6th mass extinction of species.  The current species extinction rates are estimated to be 100 to 1,000 times faster than the natural extinctions.  Ecologists warn that if the present trends continue, nearly half of all the species on earth might be wiped out within the next 100 years. 1st 2nd 3rd 4th Natural mass extinctions © 2022, Aakash BYJU'S. All rights reserved 5th 6th Anthropogenic activities are leading to 6th mass extinctions Result of Biodiversity Loss  Loss of biodiversity in a region may lead to : Decline in plant production and productivity Reduced resistance to environmental perturbations like drought Increased variability of ecosystem processes like productivity, water use, pest and disease cycle © 2022, Aakash BYJU'S. All rights reserved Causes of Biodiversity Loss Four major causes of biodiversity losses : Over exploitation Habitat loss and fragmentation © 2022, Aakash BYJU'S. All rights reserved Alien species invasions The evil quartet Co-extinctions Habitat Loss  Deforestation, filling of wetland, ploughing of grassland or burning of the forest destroyed or changed the natural habitat 6% of earth’s land area 14% of earth’s land area Earlier Habitat loss of tropical rainforests © 2022, Aakash BYJU'S. All rights reserved Today Habitat Loss  The Amazon rainforest is huge and is called the ‘lungs of the planet’ and harbours probably millions of species.  It is being cut and cleared for cultivating soybeans or for conversion to grasslands for raising beef or cattle. © 2022, Aakash BYJU'S. All rights reserved Habitat Loss  Pollution may reduce or eliminate populations of sensitive species. o Use of pesticides are linked with decline in fish-eating birds and falcons o Lead poisoning causes mortality of duck, swans and cranes o Eutrophication (nutrient enrichment) of water bodies drastically reduces species diversity Water pollution © 2022, Aakash BYJU'S. All rights reserved Landfills Industrial pollution Habitat Loss  Fragmentation: Large habitat broken into smaller fragments due to human activities, such as human settlements, building of roads, digging of canals etc. Large habitat  Animals which require larger territories, for example., mammals, birds and migrating animals are badly affected which leads to decline in their population. © 2022, Aakash BYJU'S. All rights reserved Large habitat broken, due to fragmentation Over Exploitation Human needs  Humans are dependent on nature for food, shelter, medicines and clothing. Nature  Whenever, ‘need’ turns to ‘greed’, it leads to overexploitation of natural resources. Needs turns to greed Over exploitation of a particular species reduces size of its population to an extent so that it becomes vulnerable to extinction. © 2022, Aakash BYJU'S. All rights reserved Over Exploitation Example of extinct species  Many species have gone extinct in the last 500 years due to overexploitation by humans. Passenger pigeon Dodo Steller’s Sea Cow(Russia)  Overharvesting of commercially important marine fishes, endangered its population. © 2022, Aakash BYJU'S. All rights reserved Alien Species Invasions  Alien species: are the new species entering a geographical region; also known as exotic or non-native species.  When alien species are introduced unintentionally or deliberately for any purpose, some of them turn invasive, and cause decline or extinction of indigenous or native species.  For example, Carrot grass (Parthenium) © 2022, Aakash BYJU'S. All rights reserved Water hyacinth African catfish (Clarias gariepinus) Co-extinctions  When a species becomes extinct, the plant and animal species associated with it also become extinct.  For example, co-evolved plant-pollinator mutualism, where extinction of one leads to the extinction of the other.  When a host fish species becomes extinct, its association with parasites also meets the same fate. Plant - pollinator © 2022, Aakash BYJU'S. All rights reserved Host - parasite Susceptibility to Extinction  Species more susceptible to extinction have following characteristics: Small population size and low reproductive rate E.g., Giant panda and blue whale 02 Large body size E.g., Rhinoceros, lion 01 03 High trophic level in food chain E.g., Bald eagle, Bengal tiger 04 Fixed habitat and migratory routes E.g., Whooping crane, blue whale © 2022, Aakash BYJU'S. All rights reserved Red Book and IUCN  IUCN is International Union for Conservation of Nature and Natural Resources, formerly called as World Conservation Union (WCU) from 1990 to 2008.  It has headquarters at Gland, Switzerland.  It maintains Red Data Book or Red List, which is a catalogue of threatened plants and animals facing risk of extinction. Threatened species Threatened species is the one which is liable to become extinct if they are not provided with proper habitat, food and protection to obtain its full biotic potential. © 2022, Aakash BYJU'S. All rights reserved Red Book and IUCN  Red list has 8 categories of species : Taxa No. of species Extinct [EX] Last individual has died Extinct in the wild [EW] Failed to record an individual in known habitat Critically endangered [CR] Extremely high risk of extinction in the wild in the immediate future Endangered [E] Very high risk of extinction in the wild in the near future Vulnerable [V] High risk of extinction in the wild in the medium-term future Lower risk [LR] Evaluated but they are not [CR], [E] or [V] Data deficient [DD] Inadequate data for assessment Not evaluated [NE] Not yet assessed © 2022, Aakash BYJU'S. All rights reserved Biodiversity Conservation  Ecosystems are undergoing change due to several factors like pollution, invasive species, over-exploitation by humans, climate changes etc  It is important to recognise that diversity at all levels - genetic, species and ecological and needs to be conserved. Narrowly utilitarian Reasons to conserve biodiversity Broadly utilitarian Ethical © 2022, Aakash BYJU'S. All rights reserved Narrowly Utilitarian  Human derive countless direct economic benefits from nature Food Vegetables, fruits, eggs, meat, cereals, pulses etc. Firewood For cooking and heating © 2022, Aakash BYJU'S. All rights reserved Fiber Jute, flax, hemp, cotton, coir etc Constructional material Timber in construction work, furniture, sport goods, musical instruments etc. Narrowly Utilitarian Drugs Industrial products Reserpine, derived from Rauwolfia serpentina which is used against high B.P 25% of drugs sold in market are derived from plants. For example, morphine, quinine, liquorice etc. Tannins are used in leather industry, lubricants, dyes, resins, perfumes, paper, rubber etc. Bioprospecting is a vigorous exploring of molecular, genetic and species level diversity for products of economic importance. © 2022, Aakash BYJU'S. All rights reserved Broadly Utilitarian Oxygen Pollination Plants replenish 02 in the atmosphere through photosynthesis Ecosystem services that nature provides Plants retain water and prevent run off. Plant roots hold the soil and prevent soil erosion. Flood and erosion control © 2022, Aakash BYJU'S. All rights reserved A number of organisms, like bees, birds, bats, are involved in pollination which is essential for formation of fruits and seeds Biodiversity has an attraction value Aesthetic pleasure Biodiversity Conservation  There are millions of plants, animals and microbial species on this planet, regardless of their usefulness or economical value, every species has an intrinsic value.  Humans have a moral and ethical duty to take care for their wellbeing and pass on our biological legacy in good order to future generations rather than destroying them. © 2022, Aakash BYJU'S. All rights reserved Strategies to Conserve Biodiversity Biodiversity conservation strategies In-situ conservation Hotspots Sacred grooves, sacred lakes Terrestrial © 2022, Aakash BYJU'S. All rights reserved Ex-situ conservation Protected area Biosphere reserve Sacred plants, home gardens National parks, wildlife sanctuaries Marine Seed banks, field gene banks, cryopreservation Botanical garden, arboreta, Zoological parks, wildlife safari park In-situ conservation  Ecosystem and its biodiversity at all levels are protected on site, which means we save the entire forest to save the tiger.  Strategies are of two types : hotspots and protected areas A. Hotspots  Designated priority areas, with hotspot of richest and the most threatened reservoirs of plant and animal life on earth  Key criteria for the designation of hotspots are : Very high levels of species richness © 2022, Aakash BYJU'S. All rights reserved High degree of endemism Degree of threat In-situ conservation Initially 25 + 9 added later = 34 hotspots in the world Covers 2% of land – dense in biodiversity Protection of these hotspots can decrease mass extinction by 30% Hotspots in India Western Ghats and Sri Lanka Indo - Burma Himalaya © 2022, Aakash BYJU'S. All rights reserved In-situ conservation B. Protected areas  Especially dedicated areas for the protection and maintenance of biological diversity Protected area network Sacred grooves, sacred lakes  In India : o Biosphere reserves - 18 o National parks - 106 o Wildlife sanctuaries - 565 © 2022, Aakash BYJU'S. All rights reserved Biosphere reserve National parks, wildlife sanctuaries In-situ conservation National parks :  Maintained by government and reserved for betterment of wildlife  The earliest national park is Yellowstone in USA and The Royal in Sydney, Australia.  The first national park in India was Jim Corbett National Park. NOT ALLOWED Habitat manipulation Grazing Timber collection © 2022, Aakash BYJU'S. All rights reserved Important protected animals and their National parks Taxa Protection started in National parks/ Sanctuaries Lion (Panthera leo persica) 1972 Gir National Park (Gujarat) Tiger (Panthera tigris) 1973 Corbett National Park (Uttarakhand) Sunderbans Tiger Reserve (Bengal) Snow leopard (Panthera uncia) 2009 Khangchendzonga National Park (Sikkim) Rhino (Rhinoceros unicornis) 1987 Kaziranga National Park (Assam) Elephants (Elephas maximus) 1991 Simlipal Sanctuary (Orissa) © 2022, Aakash BYJU'S. All rights reserved In-situ conservation Sanctuaries:  Land where animals are protected from all types of exploitation and habitat disturbances. ALLOWED Private ownership Timber collection Collection of forest products Tilling of land © 2022, Aakash BYJU'S. All rights reserved In-situ conservation Biosphere reserve :  Special category of protected areas, wherein tribal people are an integral component of the system  Launched by UNESCO’s Man and Biosphere Programme (MAB) in 1975  Biosphere reserves in India - 18 Buffer zone: are for research and educational purposes Core zone: is an undisturbed and legally protected ecosystem © 2022, Aakash BYJU'S. All rights reserved Transition zone: Activities like settlements, cropping, forestry, recreation, take place with proper harmony and conservation goals In-situ conservation Conservation Functions of biosphere reserve © 2022, Aakash BYJU'S. All rights reserved Development Scientific research, monitoring and education Some biosphere reserves in India Nanda Devi, Uttarakhand Manas, Assam Nokrek, Meghalaya Sunderbans, West Bengal In-situ conservation Sacred grooves :  In many cultures tracts of forest were set aside, and all the trees and wildlife within were totally protected  Also known as Islands of Pristine Forests Sacred groves in India Khasi and Jaintia Hills in Meghalaya  Sacred lakes: Pushkar lake in Rajasthan; Khecheopalri lake in Sikkim Aravali Hills of Rajasthan  Sacred plants: Ocimum sanctum (Tulsi), Ficus religiosa, Elaeocarpus floribundus (Rudraksha) etc. Western Ghat regions of Karnataka and Maharashtra © 2022, Aakash BYJU'S. All rights reserved Surguja , Chanda and Bastar areas of Madhya Pradesh In-situ conservation  Threatened animals and plants are taken away from their natural habitat and are placed under special care and protection.  Ex-situ conservation is the most desirable approach for urgent measures for endangered and threatened species. Ex-situ conservation Sacred plants, home gardens © 2022, Aakash BYJU'S. All rights reserved Seed banks, field gene banks, cryopreservation Botanical garden, arboreta, zoological parks, wildlife safari park Ex-situ conservation Cryopreservation for preserving threatened species gametes in viable and fertile conditions or longer period of time. Tissue culture for propagation of plants Seed banks for keeping seeds of different genetic strain of commercially important plants. © 2022, Aakash BYJU'S. All rights reserved Conventions on Biodiversity  Biodiversity knows no political boundaries and its conservation is therefore, a collective responsibility of all nations. All nations were called to take appropriate measures for conservation of biodiversity and sustainable utilisation of its benefits. © 2022, Aakash BYJU'S. All rights reserved Held in Rio de Janeiro The Earth Summit on Biological Diversity 1992 2002 World Summit on Sustainable Development Held in Johannesburg, South Africa 190 countries pledged their commitment to achieve by 2010, a significant reduction in the current rate of biodiversity loss at global, regional and local levels. Summary Genetic diversity is a measure of variety in genetic information contained in the organisms. Ecological diversity Species diversity Species diversity refers to the variety of species within a region. For example: Western Ghats have greater diversity of amphibians than Eastern Ghats Ecological diversity refers to the variety of ecosystem. © 2022, Aakash BYJU'S. All rights reserved Genetic diversity Summary Natural extinction Due to change in environmental conditions, species disappeared in the geological past at a very slow rate, which is known as natural extinction. Mass extinction It is dying off or extermination of a large number of species due to catastrophes. Five episodes of mass extinction of species have occurred. Anthropogenic extinction It is extermination of species caused directly or indirectly by human activities like habitat destruction, over-exploitation, hunting, pollution etc. © 2022, Aakash BYJU'S. All rights reserved Summary Four major causes of biodiversity losses : Over exploitation Habitat loss and fragmentation © 2022, Aakash BYJU'S. All rights reserved Alien species invasions The evil quartet Co-extinctions Summary Narrow utilitarian Reasons to conserve biodiversity Broadly utilitarian Ethical © 2022, Aakash BYJU'S. All rights reserved Summary Biodiversity conservation strategies In-situ conservation Hotspots Sacred grooves, sacred lakes Terrestrial © 2022, Aakash BYJU'S. All rights reserved Ex-situ conservation Protected area Biosphere reserve Sacred plants, home gardens National parks, wildlife sanctuaries Marine Seed banks, field gene banks, cryopreservation Botanical garden, arboreta, Zoological parks, wildlife safari park