Ecology - Biodiversity and Conservation

1. Biodiversity

• Species Diversity:
  • Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.1)

• Notes: - Species richness: the number of different species found in a given area. - Species composition: the relative abundance of different species in a given area. - Species abundance: the number of individuals of each species in a given area.

• Genetic Diversity:

• Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.2)

• Notes: - Genetic diversity refers to the variation in genes and alleles within a species. - It is essential for the survival and adaptation of a species to changing environmental conditions. - Loss of genetic diversity can make a species more vulnerable to disease, inbreeding, and other threats.

• Ecosystem Diversity:

• Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.3)

• Notes: - Ecosystem diversity refers to the variety of different types of ecosystems on Earth, including forests, deserts, grasslands, and wetlands. - Each ecosystem has its unique set of plants, animals, and environmental conditions. - Ecosystem diversity is essential for the functioning of the biosphere and the provision of ecosystem services.

2. Threats to Biodiversity

• Habitat Loss and Fragmentation:

• Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.4)

• Notes: - Habitat loss occurs when natural habitats are converted to other uses, such as agriculture, development, or mining. - Habitat fragmentation occurs when natural habitats are broken up into smaller and more isolated patches. - Habitat loss and fragmentation can lead to the decline and extinction of species.

• Overexploitation:

• Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.5)

• Notes: - Overexploitation occurs when a species is harvested at a rate that exceeds its ability to reproduce and survive. - Overexploitation can lead to the decline and extinction of species. - Examples of overexploitation include overfishing, overhunting, and deforestation.

• Pollution:

• Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.6)

• Notes: - Pollution can take many forms, including air pollution, water pollution, and land pollution. - Pollution can harm wildlife by directly poisoning them, by damaging their habitats, and by disrupting food chains. - Examples of pollution include industrial emissions, agricultural runoff, and oil spills.

• Climate Change:

• Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.7)

• Notes: - Climate change refers to the long-term changes in temperature, precipitation, and other climatic conditions. - Climate change can affect biodiversity by altering habitats, disrupting food chains, and increasing the risk of disease. - Examples of the impacts of climate change on biodiversity include the decline of coral reefs, the melting of glaciers, and the poleward shift of species ranges.

• Invasive Species:

• Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.8)

• Notes: - Invasive species are non-native species that have been introduced to an area and have become a threat to native species. - Invasive species can compete with native species for resources, such as food and habitat, and can also transmit diseases. - Examples of invasive species include the kudzu vine, the zebra mussel, and the brown tree snake.

3. Conservation Strategies

• In-situ Conservation:

• Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.9)

• Notes: - In-situ conservation refers to the conservation of biodiversity within its natural habitat. - In-situ conservation can be achieved through the establishment of protected areas, such as national parks and wildlife sanctuaries, as well as through sustainable land management practices.

• Ex-situ Conservation:

• Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.10)

• Notes: - Ex-situ conservation refers to the conservation of biodiversity outside of its natural habitat. - Ex-situ conservation can be achieved through the storage of seeds in seed banks, the cultivation of plants in botanical gardens, and the keeping of animals in zoos and aquariums.

• Sustainable Development:

• Textbook Reference: NCERT Biology Class 11, Chapter 16, “Environmental Issues” (Section 16.3)

• Notes: - Sustainable development refers to the use of resources in a way that meets the needs of the present without compromising the ability of future generations to meet their own needs. - Sustainable development can be achieved through the use of renewable energy sources, the reduction of pollution, and the conservation of biodiversity.

• Species Recovery Programs:

• Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.11)

• Notes: - Species recovery programs are programs aimed at restoring and protecting critically endangered species. - Species recovery programs can involve captive breeding, habitat restoration, and the reintroduction of species into their natural habitats.

• Biodiversity Hotspots:

• Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.12)

• Notes: - Biodiversity hotspots are regions of the world that are exceptionally rich in biodiversity and are also under threat from human activity. - Biodiversity hotspots are home to a large number of endemic species, which are found nowhere else in the world. - There are 36 recognized biodiversity hotspots in the world, including the Amazon rainforest, the Congo rainforest, and the Himalayas.

4. Ecosystem Services

• Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.13)

• Notes:

  • Ecosystem services are the benefits that people get from nature.
  • Ecosystem services include things like clean air, clean water, food, shelter, and medicine.
  • Biodiversity is essential for the provision of ecosystem services.
  • The loss of biodiversity can lead to the decline of ecosystem services and the negative impacts on human well-being.

5. Biodiversity Legislation and Policies

• Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.14)

• Notes:

• International Conventions:

  • The Convention on Biological Diversity (CBD) is the most important international agreement on biodiversity conservation.
  • The CBD was signed in 1992 and has been ratified by over 190 countries.
  • The CBD sets out a framework for biodiversity conservation and sustainable development.

• National Policies and Legislations:

  • India has several national policies and legislations that aim to protect biodiversity.
  • The Wildlife Protection Act (1972) provides protection for wildlife and their habitats.
  • The Forest Conservation Act (1980) restricts the clearing of forests.

6. Sustainable Resource Utilization

• Textbook Reference: NCERT Biology Class 11, Chapter 16, “Environmental Issues” (Section 16.5)

• Notes:

• Sustainable resource utilization refers to the use of resources in a way that does not deplete them for future generations.

• Examples of sustainable resource utilization include the use of renewable energy sources, the reduction of waste, and the recycling of materials.

• Sustainable resource utilization can help to protect biodiversity and ensure the long-term well-being of human populations.

7. Biogeographic Realms and Endemism

• Textbook Reference: NCERT Biology Class 12, Chapter 15, “Biodiversity and Conservation” (Section 15.15)

• Notes:

• Biogeographic realms are large regions of the Earth’s surface that are characterized by distinct assemblages of plants and animals.

• There are eight biogeographic realms: the Afrotropical Realm, the Antarctic Realm, the Australasian Realm, the Nearctic Realm, the Neotropical Realm, the Oceanian Realm, the Palearctic Realm, and the Indo-Malaysian Realm.

• Endemism refers to the occurrence of a species in a particular geographic area and nowhere else.

• Endemic species are often found in biodiversity hotspots.