Biodiversity & Conservation
KVPY – Biology (Historic Programme)
1. Simple Explanation
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Biodiversity – the variety of life on Earth, encompassing three hierarchical levels:
- Genetic diversity – variation within species (genes, alleles).
- Species diversity – number of species and their relative abundance.
- Ecosystem diversity – variety of habitats and ecological communities.
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Conservation – the protection, sustainable use, and restoration of biodiversity, aiming to prevent loss of species, ecosystems, and genetic resources.
2. Key Points
| Category | Main Ideas | Examples |
|---|---|---|
| Why Biodiversity Matters | • Ecosystem services (food, water, air purification, pollination). • Genetic resources for medicine, agriculture, industry. • Cultural, aesthetic, and recreational value. |
Pollination by bees, drought‑resistant wheat varieties, traditional medicine from medicinal plants. |
| Threats to Biodiversity | • Habitat loss & fragmentation. • Overexploitation (fishing, hunting, logging). • Pollution (chemical, plastic, noise). • Invasive species. • Climate change. • Over‑exploitation of genetic resources. |
Deforestation in the Amazon, overfishing of coral reef fish, introduction of Mimosa pigra in Australia. |
| Conservation Strategies | 1. In‑situ – protecting habitats in the wild (national parks, wildlife sanctuaries, marine protected areas). 2. Ex‑situ – conservation outside natural habitats (seed banks, botanical gardens, captive breeding). 3. Legislation & Policy – CITES, Wild Life (Protection) Act, National Biodiversity Authority. 4. Community‑Based Conservation – involving local people, indigenous knowledge, community reserves. 5. Restoration Ecology – reforestation, habitat restoration, ecological engineering. |
Giant panda reserves, Svalbard Global Seed Vault, community forest management in Nepal. |
| Assessment Tools | • Species‑Richness Index – simple count of species. • Shannon Diversity Index (H') – accounts for abundance and evenness. • Simpson’s Index (D) – probability that two randomly selected individuals belong to different species. • Red List Categories – IUCN criteria for threat status. |
Calculating H' for a forest plot; determining a species’ IUCN status. |
| International Conventions | • Convention on Biological Diversity (CBD). • Convention on International Trade in Endangered Species (CITES). • Ramsar Convention (wetlands). |
CITES Appendix I: Siberian tiger, CBD Target 12: “Reduce loss of habitat”. |
| Case Study Highlights | • Western Ghats, India – high endemism, forest fragmentation, conservation corridors. • Great Barrier Reef – bleaching due to warming, coral restoration projects. • African Savanna – poaching of elephants, community conservancies. |
“Elephant corridor” project linking protected areas in Kenya. |
3. Worked Example
Problem:
A 1 ha forest plot contains 5 tree species with the following numbers of individuals:
- Species A: 25 individuals
- Species B: 15 individuals
- Species C: 30 individuals
- Species D: 10 individuals
- Species E: 20 individuals
Compute the Shannon Diversity Index (H') and interpret the result.
Step‑by‑Step
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Total individuals (N)
(N = 25 + 15 + 30 + 10 + 20 = 100) -
Proportion of each species ((p_i = n_i / N))
| Species | (n_i) | (p_i) |
|---|---|---|
| A | 25 | 0.25 |
| B | 15 | 0.15 |
| C | 30 | 0.30 |
| D | 10 | 0.10 |
| E | 20 | 0.20 |
- Compute (p_i \ln p_i) (use natural log)
| Species | (p_i) | (\ln p_i) | (p_i \ln p_i) |
|---|---|---|---|
| A | 0.25 | –1.3863 | –0.3466 |
| B | 0.15 | –1.8971 | –0.2846 |
| C | 0.30 | –1.2030 | –0.3609 |
| D | 0.10 | –2.3026 | –0.2303 |
| E | 0.20 | –1.6094 | –0.3219 |
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Sum all (p_i \ln p_i)
(\sum p_i \ln p_i = -1.5443) -
Shannon Index
(H' = - \sum p_i \ln p_i = 1.5443)
Interpretation
- H' = 1.5443 indicates moderate diversity.
- For comparison, a completely even community of 5 species would give (H' = \ln 5 \approx 1.609).
- The plot is slightly less even, but still has high species richness and reasonable evenness.
- A higher value (closer to 2) would indicate more diversity; a lower value (<1) would signal dominance by one or two species.