🌸Chapter 13
Biodiversity and Conservation
(Summary Notes)
1. Key Definitions
|
Term |
Definition |
Example / Notes |
|
Biodiversity |
Variety of life at genetic, species, and ecosystem levels |
- |
|
Genetic Diversity |
Variation of genes within a species |
Different rice varieties |
|
Species Diversity |
Number and abundance of species in a habitat |
Tropical rainforest species |
|
Ecosystem Diversity |
Variety of ecosystems in a region |
Forests, wetlands, deserts |
|
Endemic Species |
Found only in a specific geographic area |
Lion-tailed macaque |
|
Exotic Species |
Introduced from another region |
Eucalyptus |
|
Keystone Species |
Species with disproportionate effect on ecosystem |
Tiger, Honeybee |
|
Biodiversity Hotspot |
Rich in endemic species and under threat |
Western Ghats, Himalaya |
|
Threatened Species |
At risk of extinction |
Bengal Tiger (Endangered) |
|
Extinction |
Permanent loss of species |
Dodo bird |
|
In-situ Conservation |
Conservation in natural habitat |
National Parks, Biosphere Reserves |
|
Ex-situ Conservation |
Conservation outside natural habitat |
Zoos, Botanical Gardens, Seed Banks |
2. Levels of Biodiversity
Diagram: Levels of Biodiversity
Biodiversity
├─ Genetic Diversity → Variation
within species
├─ Species Diversity → Number &
abundance of species
└─ Ecosystem Diversity → Variety of
ecosystems
Keywords: Genetic variation, Endemism, Species richness, Species
evenness
3. Importance of Biodiversity
A. Ecological
- Maintains food chains and
ecological balance
- Nutrient cycling and soil
formation
- Climate regulation
B. Economic
- Timber, fuel, fibers, food
- Medicinal plants and drugs
(Taxol, Artemisinin)
- Ecotourism
C. Cultural & Aesthetic
- Sacred groves
- Religious and spiritual values
- Aesthetic and recreational
values
NCERT Keywords: Keystone species, Ecosystem services, Sacred groves
4. Biodiversity Hotspots in India
Diagram: Indian Biodiversity Hotspots Map (Sketch)
1. Himalaya → Endemics: Red Panda
2. Indo-Burma → Endemics: Namdapha
Flying Squirrel
3. Sundalands (Nicobar Islands) →
Endemics: Nicobar Megapode
4. Western Ghats → Endemics:
Neelakurinji, Lion-tailed macaque
Keywords: Endemism, Species richness, Hotspot criteria
5. Threats to Biodiversity
|
Threat |
Explanation |
Example |
|
Habitat Loss |
Deforestation, urbanization |
Rainforest clearance |
|
Fragmentation |
Habitat divided into patches |
Isolated forest fragments |
|
Overexploitation |
Excessive use of species |
Overfishing of Hilsa |
|
Invasive Species |
Non-native species outcompete natives |
Water hyacinth |
|
Pollution |
Contamination of air, water, soil |
Pesticides harming birds |
|
Climate Change |
Temperature/rainfall changes |
Coral bleaching |
|
Hunting/Poaching |
Illegal killing of species |
Tigers, Elephants |
Keywords: Anthropogenic threats, Human activities, Extinction risk
6. Conservation Strategies
A. In-Situ Conservation
- Definition: Protecting species in their
natural habitats
- Methods:
- National Parks → Strict
protection, no human activity
- Wildlife Sanctuaries → Some
regulated human activity allowed
- Biosphere Reserves → Core,
Buffer, Transition zones
- Sacred Groves → Protected due
to religious beliefs
Examples: Jim Corbett NP, Nilgiri Biosphere Reserve, Rushikulya
Turtle Sanctuary
Keywords: Core zone, Buffer zone, Sacred groves, Habitat protection
B. Ex-Situ Conservation
- Definition: Conservation outside natural
habitats
- Methods:
- Zoos → Captive breeding of
endangered species
- Botanical Gardens →
Propagation of rare plants
- Seed Banks → Store seeds
long-term (NBPGR)
- Tissue Culture → Lab propagation
of rare plants
Keywords: Captive breeding, Genetic preservation, Seed vaults,
Botanical garden
C. Global and Community Efforts
- CITES: International treaty to
prevent trade in endangered species
- Project Tiger: Protect tigers and their
habitats
- Project Elephant: Protect elephants and
migratory corridors
- Community participation: Sacred groves, sustainable
use, local monitoring
Keywords: Conservation projects, International treaties,
Community-based conservation
7. Important Species to Remember (India)
|
Category |
Species |
|
Endangered Animal |
Bengal Tiger, Asiatic Lion, Ganges River Dolphin |
|
Endemic Animal |
Lion-tailed Macaque, Indian Peafowl, Purple Frog |
|
Endangered Plant |
Nepenthes khasiana, Santalum album |
|
Endemic Plant |
Neelakurinji, Sandalwood |
Keywords: Endemic, Endangered, Conservation priority
8. Quick NCERT Keywords for Exams
- Biodiversity, Genetic
diversity, Species diversity, Ecosystem diversity
- Endemism, Keystone species,
Megadiversity, Biodiversity hotspot
- Habitat loss, Overexploitation,
Pollution, Climate change
- In-situ, Ex-situ, National
Park, Wildlife Sanctuary, Biosphere Reserve
- CITES, Project Tiger, Project
Elephant, Sacred groves
9. Sample Diagrams for Quick Study
A. Levels of Biodiversity
Biodiversity
├─ Genetic Diversity
├─ Species Diversity
└─ Ecosystem Diversity
B. In-situ Conservation Zones (Biosphere Reserve)
Core Zone → Strictly protected
Buffer Zone → Research &
education
Transition Zone → Sustainable human
use
C. Threats to Biodiversity Flowchart
Human Activities
├─ Deforestation → Habitat loss
├─ Overexploitation → Population
decline
├─ Pollution → Species mortality
└─ Invasive Species → Native species
decline
✅ Tips for Last-Minute Exam Prep
1.
Memorize
key definitions and examples.
2.
Focus
on hotspots, endemic species, and threatened species.
3.
Draw
simple diagrams for levels of biodiversity, biosphere reserves, and
threats.
4.
Remember
project names: Project Tiger, Project Elephant, Sacred groves.
5.
Go
through NCERT keywords for scoring high marks in both board and NEET
exams.
