Biodiversity and its Conservation Flashcards
(50 cards)
Who coined the term biodiversity
Walter Rosen
Popularised by Edward Wilson
Define biodiversity
Biodiversity is the sum total of species richness i.e. the number of species of plants, animals and micro-organisms inhabiting a green habitat
Types of biodiversity
- Genetic diversity
- Species diversity
- Ecosystem diversity
Genetic diversity
- Variation of genes within species
- Occurs at molecular level
- E.g. 50,000 genetically different strains of rice in India 1000 varieties of mangoes
Species diversity
Refers to the variety of species within a region
E.g. Western Ghats have greater amphibian diversity than Eastern Ghats
Diversity of bird species in Amazon rainforest
Ecosystem diversity
Refers to different landforms, each of which support different and specific vegetation
E.g. India has deserts, rainforests, mangroves, coral reefs, and has a greater ecosystem diversity than Scandinavian countries like Norway
What is latitudinal gradient
Species diversity decreases as we move away from the equator towards the poles.
Tropics harbour more species than termperate or polar areas
GRW there is greater biological diversity in the tropics
- Tropical latitudes have remained relatively undisturbed in the past, and thus had a long evolutionary time for species diversification
- Constant enviornments promote niche specialisation and lead to greater species diversity
- There is more solar energy in the tropics which contributes to higher productivity which in turn might contribute to greater diversity
What is species-area relation equation
log S= log C + Z log A
S= species richness
A= area
Z= slope of the line
C= y intercept
see graph in textbook
Rivet-popper hypothesis
Used by Paul Ehrlich
According to this hypothesis, the natural ecosystems of the earth are analogous to the parts of an airplane that make it a suitable vehicle for the travel of human beings
- Airplane- ecosystem joined together using thousands of rivets- species
- If one of the rivets (species) inside are removed (go extinct) the ecosystem will not be affected
- But if one of the keystone rivets (keystone species) outside are removed, there will be ecological imbalance
Importance of biodiversity
- Economics and agriculture
- Pharmaceuticals
- Ethical and aesthetic values
- Traditional food plants
Importance of biodiversity: Economics and agriculture
- Biodiversity is important in agriculture due to its use of genetic traits from wild relatives of domestic crops.
- Biodiversity supports economic growth and sustainable development through direct harvest, nature tourism, and improved domestic crops via wild genes.
- Wild species contribute to crop productivity and act as sources of medicine and bioremediation.
- Genetic diversity in agriculture allows crops and animals to adapt to diverse environments and growing conditions.
Importance of biodiversity- Pharmaceuticals
- Key drugs like digitalis, morphine, quinine, and antibiotics originate from wild plants, fungi, or organisms.
- About 75% of plant-derived drugs were found due to their use in indigenous medicine.
- Indigenous forest communities use around 1300 plant species for medicinal and related purposes.
- Developing nations heavily rely on traditional medicine, often utilizing plant extracts for primary healthcare.
- Aloe vera extracts are widely used for skin softening and wrinkle prevention.
Importance of biodiversity- aesthetics and ethical value
- These are base don religious feelings of people that life forms have intrinsic value and deserve protection from destruction by humanity.
- Beauty of birds, trees, flowers, nature is widely enjoyed and has economic value
- Biodiversity directly enhances quality of life and aesthetic pleasure.
- It contributes to outdoor recreation and scenic enjoyment.
- Recreational activities like hiking, bird watching, river rafting, and more are made possible by biodiversity.
- Biodiversity supports the creation of new horticultural species and wildlife conservation.
- Zoos and parks dedicated to specific species like snakes, crocodiles, and butterflies add to the aesthetic value.
Importance of biodiversity: Traditional food plants
- Subsistence farmers have been producing or gathering plants from the wild or semi-wild that are accepted as desirable sources of food.
- Millions of people use such traditional plants for their food needs
Explain the narrowly utilitarian arguments in favour of conservation of biodiversity
The narrowly utilitarian arguments for conserving biodiversity as they provide direct economic benefits from nature like food, firewood, fibre, construction material, industrial products and products of medicinal importance.
Explain the broadly utilitarian arguments in favour of conservation of biodiversity
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2. As an estimate the fast dwindling amazon forest produces about 20% of the total oxygen in the Earth’s atmosphere.
3. Pollination by bees, birds etc is another service the ecosystem provides
4. Aesthetic pleasure we get from biodiversity cannot be measured in terms of money
Explain the ethical arguments in favour of conservation of biodiversity
- The ethical argument is that we share biodiversity with millions of plant, animal and microbe species.
- Every species has an intrinsic value, even if it may not be of any economic value to us.
- We also have a moral duty to care for their well-being and pass on our biological legacy in good order to future generations
Causes of loss of biodiversity
- habitat loss and fragmentation
- over-exploitation
- alien species invasion
- co-extinction
- pet-trade
Causes of loss of biodiversity: habitat loss and fragmentation
- Habitat fragmentation occurs when large blocks of habitat are cut into smaller pieces by development such as roads or housing. The remaining blocks of habitat may be too small to sustain populations of a number of species and the fragmentation often results in barriers to species movement.
- Vast expanse of forest area is under a lot of stress due to industrialisation
- Human activities like cattle ranching, timber exploitation leads to lack of resources
Causes of loss of biodiversity- overexploitation
- Overexploitation of natural resources
- Wildlife poaching, natural resources being taken from forested areas (illegal trade of sandalwood, spices etc.)
- Illegal farming of narcotic drugs (clearing forested area in the core of the forest and subsequent burnig of area + surrounding forest to escape law enforcement authorities). This reduces the quality of the soil (topsoil is disrupted and microhabitat is destoyed)
- Tiger population, African elephant population is decreasing for ivory trade, trophies, souvenirs
Loss of biodiversity: alien species invasion
- Eutrophication- Condition where there is an extensive growth of algae, water hyacinth due to increased amount of organic content (which increases due to pollution) in a habitat that is not their own. When organic content increases, oxygen decreases (dissolved oxygen decreases– biological oxygen demand increases)
- Parthenium, a weed- invasion of parthenium which utilises resources which species local to the area would use otherwise
- Rats are frequently identified with catastrophic declines of birds on islands, and transmit the plague bacterium via fleas in certain areas of the world.
Loss of biodiversity pet trade
Exotic parrots, snakes getting traded leads to loss of habitat, ecosystem.
Leads to ecological imbalance
Loss of biodiversity- co-extinction
- Co-extinction refers to extinction due to the obligatory association of plants or animals.
- If flowers with long corolla are extinct then ornithophilous birds (birds with long beak) go extinct
- If eucalyptus trees go extinct, the koala bears go extinct
- When a species becomes extinct, then plants and animals that were dependent on it also become extinct in due time