Biodiversity Conservation | Biology Class 12 - NEET PDF Download

Why Should We Conserve Biodiversity?

Three Categories of Arguments:

1. Narrowly Utilitarian Arguments

• Direct economic benefits from nature
• Food sources: cereals, pulses, fruits
• Materials: firewood, fiber, construction materials
• Industrial products: tannins, lubricants, dyes, resins, perfumes
• Medicinal importance: Over 25% of drugs worldwide derived from plants
• 25,000 plant species used in traditional medicines globally
• Bioprospecting potential: exploring molecular, genetic, and species-level diversity for economic products
• Unknown number of medicinally useful plants in tropical rainforests yet to be discovered

2. Broadly Utilitarian Arguments

• Biodiversity's role in ecosystem services
• Amazon forest produces 20% of Earth's atmospheric oxygen through photosynthesis
• Pollination services by bees, bumblebees, birds, and bats essential for fruits and seeds
• Economic value of natural services difficult to quantify
• Intangible benefits: aesthetic pleasures (walking through woods, spring flowers, bird songs)

3. Ethical Arguments

• Moral obligation to millions of species sharing the planet
• Every species has intrinsic value regardless of economic importance
• Moral duty to care for species' well-being
• Responsibility to pass biological legacy to future generations

How Do We Conserve Biodiversity?

In Situ (On Site) Conservation

• Conserving entire ecosystems to protect all biodiversity levels
• Example: saving entire forest to save the tiger

Biodiversity Hotspots:

• 34 biodiversity hotspots globally (initially 25, then 9 added)
• Regions with very high species richness and endemism
• Endemic species: confined to specific region, not found elsewhere
• Cover less than 2% of Earth's land area but harbor extremely high species numbers
• Strict protection could reduce mass extinctions by almost 30%
• Regions of accelerated habitat loss

Three Hotspots Covering India:

1. Western Ghats and Sri Lanka
2. Indo-Burma
3. Himalaya

Protected Areas in India:

• 14 biosphere reserves
• 90 national parks
• 448 wildlife sanctuaries
• Sacred groves: culturally protected forest tracts in Khasi and Jaintia Hills (Meghalaya), Aravalli Hills (Rajasthan), Western Ghats (Karnataka and Maharashtra), Sarguja, Chanda and Bastar areas (Madhya Pradesh)
• Sacred groves in Meghalaya: last refuges for rare and threatened plants

Ex Situ (Off Site) Conservation

• Used for endangered or threatened species needing urgent measures
• Species facing very high risk of extinction in wild

Facilities:

• Zoological parks
• Botanical gardens
• Wildlife safari parks
• Some animals extinct in wild but maintained in zoos

Advanced Techniques:

• Cryopreservation of gametes for long-term storage in viable, fertile condition
• In vitro fertilization of eggs
• Plant propagation through tissue culture methods
• Seed banks for different genetic strains of commercially important plants

Global Conservation Efforts

Convention on Biological Diversity (1992)

• The Earth Summit in Rio de Janeiro
• Called for conservation of biodiversity and sustainable utilization
• Recognition that biodiversity knows no political boundaries
• Collective responsibility of all nations

World Summit on Sustainable Development (2002)

• Held in Johannesburg, South Africa
• 190 countries pledged commitment
• Goal: significant reduction in biodiversity loss by 2010 at global, regional, and local levels