Unit 2: Biodiversity and conservation

Definition and Levels of Biodiversity

Biodiversity (or Biological Diversity) is the variety and variability of life on Earth. It is a measure of variation at the genetic, species, and ecosystem level.

• 1. Genetic Diversity: The total number of genetic characteristics in the genetic makeup of a species. It is the variety of genes (alleles) within a single species. (e.g., different breeds of dogs; different varieties of rice). High genetic diversity helps a species adapt to change.
• 2. Species Diversity: The variety of different species within a particular region (combining species richness and species evenness).
• 3. Ecosystem Diversity: The variety of different habitats, communities, and ecological processes within an area (e.g., a landscape with a forest, a wetland, and a river has high ecosystem diversity).

Biodiversity Hot Spots

A biodiversity hotspot is a biogeographic region with extremely high levels of species richness and endemism (species found nowhere else) that is under severe threat from human activities.

To qualify as a hotspot, a region must meet two criteria:

1. It must contain at least 1,500 species of vascular plants (> 0.5% of the world's total) as endemics.
2. It must have lost at least 70% of its original habitat.

India has four major biodiversity hotspots:

• The Himalayas
• The Western Ghats
• The Indo-Burma region
• Sundaland (includes the Nicobar Islands)

[Image of a world map showing biodiversity hotspots]

Values of Biodiversity

The values of biodiversity describe the reasons why it is so important to protect.

• Direct Use Value (Economic): Consumptive (e.g., fuelwood, food, medicine) and productive (e.g., timber, NTFPs).
• Indirect Use Value (Ecological): Ecosystem services that support human life. (e.g., pollination, climate regulation, oxygen production, soil formation, flood control).
• Ethical Value: The belief that every species has an intrinsic right to exist, regardless of its usefulness to humans.
• Aesthetic Value: The beauty of nature, which provides recreation, tourism, and spiritual well-being.

Threats to Biodiversity

The main causes of biodiversity loss are often summarized by the acronym HIPPO:

• H - Habitat Loss and Fragmentation: The single greatest threat. (e.g., deforestation for agriculture, urbanization).
• I - Invasive Alien Species: Non-native species that outcompete native species (e.g., Water Hyacinth, *Lantana camara*).
• P - Pollution: Chemical pollutants (pesticides, heavy metals) that harm or kill organisms.
• P - Population (Human): Overpopulation leads to over-consumption and more habitat loss.
• O - Overexploitation: Harvesting species from the wild at rates faster than they can recover (e.g., overfishing, poaching).

Conservation of Biodiversity

There are two primary strategies for conserving biodiversity:

1. In-situ (On-site) Conservation

Protecting species in their natural habitat. This is the most effective strategy as it conserves the entire ecosystem.

• National Parks: High level of protection; most human activities are prohibited.
• Wildlife Sanctuaries: Protection for specific species; some human activities may be allowed.
• Biosphere Reserves: Large areas that include zones for core protection, buffer (research, education), and transition (sustainable human use).
• Sacred Groves: Patches of forest protected by local communities due to religious beliefs.

2. Ex-situ (Off-site) Conservation

Conserving species outside their natural habitat. This is used when a species is critically endangered and its natural habitat is lost or unsafe.

• Zoological Parks (Zoos): Protect and breed endangered animals.
• Botanical Gardens: Cultivate and protect rare and endangered plants.
• Seed Banks: Store seeds in cold, dry conditions for long-term preservation.
• Gene Banks: Store genetic material (sperm, eggs, DNA) at very low temperatures (cryopreservation).

India-Specific Conservation Efforts

• Sacred Groves of North East India: These are traditional community-protected forests that are hotspots of biodiversity. They are protected for cultural and religious reasons and serve as important refuges for rare and endemic species.
• Tiger Task Force: Refers to the national-level efforts and bodies (like the National Tiger Conservation Authority - NTCA) responsible for managing "Project Tiger." Its goal is to protect tigers and their habitats to ensure a viable population.
• The Indian Rhino Vision 2020 (IRV 2020): A major initiative in Assam to increase the population of the one-horned rhino. The main goal was to "translocate" rhinos from high-density areas (like Kaziranga) to other protected areas (like Manas) to create new, viable populations and reduce risks from poaching and disease.

IUCN Red List Categories

The IUCN (International Union for Conservation of Nature) Red List is the world's most comprehensive inventory of the global conservation status of species. It classifies species based on their risk of extinction.

Key Categories (in order of increasing risk):

• Least Concern (LC): Widespread and abundant.
• Near Threatened (NT): Likely to become threatened in the near future.
• Vulnerable (VU): High risk of extinction in the wild.
• Endangered (EN): Very high risk of extinction in the wild.
• Critically Endangered (CR): Extremely high risk of extinction in the wild.
• Extinct in the Wild (EW): Survives only in captivity or as a naturalized population outside its historic range.
• Extinct (EX): No known individuals remaining.