UNIT III

Definition: Variety and variability of life on Earth, encompassing complex interactions among all living things, including micro-organisms.
Etymology:
- Bio = Life
- Diversity = Variety

Genetic Diversity: Variability in genes among individuals of the same species.
- Example: Variations in rice (Oryza sativa) varieties in terms of color, size, aroma, and nutrient content.
Species Diversity: Variability within a species and between different species in a community.
- Measures species richness and abundance using indices like Shannon-Wiener and Simpson index.
- Estimates of living species range from 10 million to 50 million; approximately 1.5 million have been described.
Ecosystem Diversity: Variability among ecosystems, reflecting ecological complexity related to different physical parameters such as moisture, temperature, and altitude.
- Essential for maintaining ecological balance; loss disrupts functioning between ecosystem types.

Consumptive Use Value: Direct use for goods such as food, building materials, medicine, etc.
Productive Use Value: Marketable products from wildlife e.g., elephant tusks, silk.
Social Value: Cultural and religious significance attached to certain species and ecosystems.
Ethical Value: Exists for species solely based on the belief that all life must be preserved; example: emotions associated with extinct species.
Aesthetic Value: Value derived from beauty in nature and experiences of eco-tourism; estimated at roughly $12 billion annual revenue.
Option Value: Potential future uses of biodiversity, such as undiscovered medical resources in ecosystems.
Ecosystem Service Value: Benefits ecosystems provide to prevent issues like soil erosion and maintain soil fertility.

Loss of Habitat: Main cause of biodiversity loss, affecting natural habitats and leading to fragmentation.
- Rapid disappearance of tropical forests (~0.6% annually).
Poaching: Illegal wildlife trade continues despite international bans.
- High value of endangered products in affluent markets.
Man-Wildlife Conflicts: Encroachment on wildlife territories leads to conflicts, often resulting in violence against animals.

In Situ Conservation: Conservation of species in their natural habitats, such as National Parks and Biosphere Reserves.
- India: 7 Biosphere Reserves, 80 National Parks, 420 Wildlife Sanctuaries.
Ex Situ Conservation: Conservation outside natural habitats using zoos, gene banks, etc.
- NBPGR in New Delhi preserves agricultural varieties; maintaining biodiversity for crop improvement.

Biodiversity: Critical for resilience and stability; enhances adaptive capacity.
Interdependence: Organisms interact through food webs and nutrient cycles sustaining life.
Energy Flow: Transfer of energy through food chains beginning with photosynthesis.
Nutrient Cycling: Essential processes ensure availability of vital nutrients.
Dynamic Balance: Ecosystems maintain equilibrium despite disturbances.
Abiotic Factors: Climate, soil, and water shape ecosystems.
Succession: Natural progression of ecosystems over time.

Provisioning Services: Delivering food, water, and materials.
Regulating Services: Natural processes regulating air quality, climate, and water.
Supporting Services: Necessary for habitat maintenance and genetic diversity.
Cultural Services: Non-material benefits from ecosystems, including recreation and spiritual enrichment.

Air Pollution: Harmful substances in the air from natural (volcanoes, forest fires) and anthropogenic (industrial emissions, vehicular activity) sources.
- Control Measures: Use of clean fuels, pollution control devices (e.g., electrostatic precipitators).
Water Pollution: Changes making water unsuitable for use, caused by industrial discharge, sewage, agrochemicals.
- Control Measures: Treating effluents, managing run-off.
Soil Pollution: Contamination from waste disposal and hazardous materials.
- Control Measures: Proper waste management, sustainable agricultural practices.
Thermal Pollution: Waste heat from power plants altering aquatic ecosystems.
- Control Measures: Implementation of cooling technologies.

Biodiversity is crucial for ecosystem health and human well-being, providing numerous services and resources. Protecting it against threats like habitat loss, poaching, and pollution is vital for sustaining our planet's ecological balance.