Unit IV: Biodiversity and Conservation

1. Levels of Biological Diversity: Genetic, Species, and Ecosystem

Diversity
Introduction:

Biodiversity refers to the variety of life on Earth and is classified into three levels: genetic
diversity, species diversity, and ecosystem diversity. These levels ensure the stability and
functioning of ecosystems.

1. Genetic Diversity:

• Refers to the variation in genes within a species.

• Helps species adapt to environmental changes and resist diseases.
• Example: Rice varieties in India (Basmati, Indica, Japonica) show genetic diversity.

2. Species Diversity:

• Represents the variety of species within a given area or ecosystem.

• Higher species diversity makes ecosystems more resilient.
• Example: The Amazon Rainforest has the highest species diversity of any
ecosystem.

3. Ecosystem Diversity:

• Refers to the variety of ecosystems in a region.

• Includes terrestrial (forests, grasslands) and aquatic (marine, freshwater)
ecosystems.
• Example: India has diverse ecosystems such as the Himalayas, Western Ghats, and
Sundarbans.

Conclusion:

These three levels of biodiversity are interconnected. The loss of genetic diversity affects species
survival, and species extinction disrupts ecosystems. Conservation efforts must focus on all
levels to maintain ecological balance.

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2. Biogeographic Zones of India
Introduction:

Biogeographic zones are regions classified based on geography, climate, and species
composition. India has 10 biogeographic zones, each with unique flora and fauna.

1. The 10 Biogeographic Zones of India:

1. Trans-Himalayan Zone – Cold deserts of Ladakh and Spiti; home to snow leopards.
2. Himalayan Zone – Includes the Western and Eastern Himalayas; rich in
rhododendrons and red pandas.
3. Indian Desert – Covers Rajasthan and Gujarat; characterized by camels and desert
foxes.
4. Semi-Arid Zone – Includes Punjab, Haryana, and parts of Gujarat; habitat for
blackbucks.
5. Western Ghats – A biodiversity hotspot with endemic species like the Malabar
civet.
6. Deccan Plateau – Covers central India; home to deciduous forests and Indian
bison.
7. Gangetic Plain – Fertile land with rich bird diversity and the Ganges river dolphin.
8. Coasts – Marine ecosystems with mangroves, coral reefs, and turtles.
9. Northeast India – A biodiversity hotspot with one-horned rhinoceros and orchids.
10. Islands – Andaman and Nicobar Islands with unique species like the Nicobar
pigeon.

Conclusion:

India's biogeographic zones support a vast range of species. Conservation efforts should be
tailored to each zone to protect its unique biodiversity.

3. Biodiversity Patterns and Global Biodiversity Hotspots

Introduction:

Biodiversity is not evenly distributed across the planet. Certain regions, known as biodiversity
hotspots, have exceptionally high species richness.

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1. Biodiversity Patterns:

• Latitudinal Gradient – Biodiversity increases from the poles to the tropics.

• Altitude and Depth – Mountain biodiversity decreases with altitude, while marine
biodiversity decreases with depth.

2. Global Biodiversity Hotspots:

Norman Myers identified 36 biodiversity hotspots, characterized by:

1. High species richness.

2. Large number of endemic species.
3. Significant habitat loss.

3. Major Biodiversity Hotspots:

1. Amazon Rainforest – The world's largest tropical rainforest.

2. Congo Basin – Rich in primates like gorillas and chimpanzees.
3. Indo-Burma Region – Home to many freshwater turtles.
4. Sundaland – Includes the Nicobar Islands.

Conclusion:

Biodiversity hotspots are crucial for conservation. Protecting them ensures the survival of unique
species and maintains ecological balance.

4. India as a Mega-Biodiversity Nation

Introduction:

India is one of the 17 mega-biodiverse countries in the world, home to 7-8% of all recorded
species.

1. Factors Contributing to India's Biodiversity:

• Diverse geography – Himalayas, deserts, plateaus, coasts, and islands.

• Varied climate – Tropical, temperate, and alpine zones.
• High endemism – Over 45,000 plant species and 90,000 animal species.

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2. Unique Biodiversity Regions:

1. Himalayas – Snow leopards, red pandas, and medicinal plants.

2. Western Ghats – Endemic species like the Nilgiri tahr.
3. Sundarbans – The world’s largest mangrove forest, home to the Royal Bengal tiger.
4. Northeast India – High orchid and butterfly diversity.

Conclusion:

India’s biodiversity is its strength. Conservation policies like Project Tiger, Biosphere
Reserves, and Wildlife Sanctuaries are essential to preserve this heritage.

5. Endangered and Endemic Species of India

Introduction:

India has many species that are endemic (found only in India) and endangered (at risk of
extinction).

1. Endangered Species:

• Royal Bengal Tiger – Threatened due to poaching and habitat loss.

• Asiatic Lion – Found only in Gir National Park.
• Great Indian Bustard – One of the most endangered birds in India.
• One-Horned Rhinoceros – Found in Assam’s Kaziranga National Park.

2. Endemic Species:

• Lion-tailed Macaque – Western Ghats.

• Malabar Civet – Endemic to South India.
• Purple Frog – Found in Kerala.
• Kashmir Stag (Hangul) – Found in Kashmir’s forests.

Conclusion:

Efforts like captive breeding, wildlife sanctuaries, and anti-poaching laws are crucial to
protect these species.

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6. Threats to Biodiversity
1. Habitat Loss:

• Deforestation due to urbanization and agriculture.

• Example: Amazon rainforest destruction.

2. Poaching of Wildlife:

• Illegal hunting of animals for skin, bones, and tusks.

• Example: Poaching of tigers for their skin.

3. Man-Wildlife Conflicts:

• Encroachment of human settlements into animal habitats.

• Example: Elephant attacks in villages.

4. Biological Invasions:

• Introduction of non-native species harming native ecosystems.

• Example: Water hyacinth choking Indian water bodies.

Conclusion:

Strict enforcement of wildlife protection laws and community participation can help mitigate
these threats.

7. Conservation of Biodiversity: In-Situ and Ex-Situ Methods

1. In-Situ Conservation (Conserving in Natural Habitat):

• National Parks – Kaziranga, Jim Corbett.

• Wildlife Sanctuaries – Gir, Sundarbans.
• Biosphere Reserves – Nilgiri, Nanda Devi.

2. Ex-Situ Conservation (Outside Natural Habitat):

• Zoos and Botanical Gardens – Conservation of endangered species.

• Seed Banks – Preservation of plant species.

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Conclusion:

Both methods are necessary for effective biodiversity conservation.

8. Ecosystem and Biodiversity Services

1. Ecological Value:

• Biodiversity maintains food chains and ecological balance.

2. Economic Value:

• Provides resources like timber, medicine, and fish.

3. Social and Ethical Value:

• Indigenous people depend on forests for livelihood.

4. Aesthetic and Informational Value:

• Biodiversity enhances tourism and scientific research.

Conclusion:

Biodiversity is essential for the planet’s sustainability and human survival.

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