Class 8 Chapter 4 Biodiversity and Environment

 What is Biodiversity? What is Environment?

• Biodiversity → Variety of life forms (plants, animals, microorganisms) at genetic, species, and ecosystem levels.
• Environment → Surroundings (living + non-living) where organisms exist and interact.
• Interrelationship:
  • Biodiversity depends on environment for survival.
  • Healthy environment ensures diverse species thrive.
  • Degraded environment → biodiversity loss.

Exam Tip: Always link biodiversity and environment as interdependent.

 Types of Biodiversity

a. Genetic Diversity → Variability in genes within a species (e.g., rice varieties, dog breeds).
b. Species Diversity → Variety of species in an ecosystem (e.g., tigers, rhinos, birds).
c. Ecosystem Diversity → Variety of ecosystems (forests, wetlands, grasslands, mountains).

Importance of Biodiversity

1. Provides food, medicine, raw materials.
2. Maintains ecological balance and ecosystem services (e.g., pollination).
3. Preserves cultural and aesthetic values.
4. Supports tourism and economy.

Present Status of Biodiversity in Nepal

• Nepal = biodiversity hotspot due to altitudinal variation (60m–8848m).
• Hosts >118 ecosystems, >6500 flowering plants, >185 mammals, >900 birds.
• Endangered species: Bengal tiger, one-horned rhino, red panda, snow leopard.
• Biodiversity declining due to human pressure and climate change.

 Causes of Biodiversity Degradation

i. Destruction of natural habitat (deforestation, urbanization).
ii. Contamination of air, water, soil → affects species survival.
iii. Over-harvesting of natural resources (timber, medicinal plants, overfishing).
iv. Introduction of non-native species (e.g., water hyacinth).
v. Altered weather patterns (climate change, global warming).
vi. Human influence → hunting, poaching, illegal wildlife trade.

Biodiversity Conservation

Main Methods:

1. Protection of natural habitats.
2. Establishment of protected areas (national parks, wildlife reserves).
3. Legal frameworks and strict enforcement.
4. Community participation (community forestry).
5. Awareness, education, and sustainable use of resources.

 In-situ and Ex-situ Conservation

a. In-situ Conservation (On-site)

• Conservation of species in their natural habitat.
• In Nepal: National parks, wildlife reserves, conservation areas, buffer zones.
• Includes: Sagarmatha NP, Chitwan NP, Annapurna Conservation Area.
• Challenges: Human–wildlife conflict, lack of resources, poaching, climate change.
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b. Ex-situ Conservation (Off-site)

• Conservation outside natural habitat.
• In Nepal: Botanical gardens, zoos, seed banks, captive breeding centers.
• Includes: Central Zoo (Jawalakhel), Godawari Botanical Garden.
• Challenges: High cost, limited facilities, reduced genetic variability.

Interesting Facts

• Nepal has 2.27% of world’s flowering plants and 9.3% of world’s bird species despite small area.
• Chitwan NP is a UNESCO World Heritage site due to biodiversity richness.

Mnemonics / Memory Aids

Causes of Biodiversity Loss → “H.O.C.A.N.”

• H → Habitat destruction
• O → Over-harvesting
• C → Contamination
• A → Alien species (non-native)
• N → Natural changes (climate/weather)

Summary / Quick Revision

• Biodiversity = variety of genes, species, and ecosystems.
• Environment supports biodiversity; both are interdependent.
• Types: genetic, species, ecosystem.
• Importance: food, medicine, balance, economy.
• Status in Nepal: very rich but declining.
• Causes of degradation: habitat destruction, pollution, overuse, non-native species, climate change, poaching.
• Conservation: In-situ (parks, reserves) and Ex-situ (zoos, gardens).

• Sustainable Development (SD) → Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
• First highlighted in the Brundtland Report (1987).
• Balances economic growth, social equity, and environmental protection.

Exam Tip: Always use the definition “development meeting present needs without harming future needs.”

Aspects of Sustainable Development

1. Environmental Aspects
   • Conservation of biodiversity, ecosystems, and natural resources.
   • Pollution control, renewable energy, waste management.
2. Economic Aspects
   • Growth through sustainable industries, eco-tourism, green jobs.
   • Equitable use of resources, poverty reduction.
3. Social Aspects
   • Social justice, gender equality, education, healthcare.
   • Community participation in development.

 Principles of Sustainable Development

a. Ecosystem and Biodiversity Conservation → Protect forests, wildlife, soil, and water for future use.
b. Population Control & Human Resource Management → Balance population growth with resources; promote skill development.
c. Culture Conservation & Community Participation → Involve local communities; respect traditional knowledge and cultural heritage.

   Importance of Sustainable Development (5 points)

1. Ensures long-term resource availability.
2. Reduces poverty and inequality.
3. Protects environment and biodiversity.
4. Improves quality of life and social equity.
5. Promotes stable economy with minimal environmental harm.

Sustainable Development Goals (Global, adopted by UN, 2015)

•  No Poverty
•  Zero Hunger
•  Good Health and Well-being
•  Quality Education
• Gender Equality
• Clean Water and Sanitation
•  Affordable and Clean Energy

(Note: Total SDGs = 17, but focus on above 7 for exam.)

Nepal’s General Efforts (4 points)

1. Policies aligned with SDGs (15th Development Plan).
2. Community forestry and eco-tourism promotion.
3. Investments in health, education, renewable energy.
4. Collaboration with international organizations (UNDP, WWF, IUCN).

Nepal’s Efforts for Biodiversity-related SDGs

1. National Biodiversity Strategy and Action Plan (NBSAP) – roadmap for biodiversity protection.
2. Protected Areas & Conservation Initiatives – national parks, reserves, buffer zones.
3. Community Forestry Programs – local participation in forest management.
4. International Cooperation – conventions (CBD, CITES, Ramsar).
5. Climate Change Adaptation & Mitigation – renewable energy, reforestation, carbon trading.
6. Endangered Species Conservation – tiger census, rhino protection, red panda initiatives.
7. Research & Monitoring – biodiversity surveys, wildlife monitoring.
8. Education & Awareness – biodiversity campaigns, eco-clubs in schools.
9. Inclusive Conservation Policies – women, marginalized communities in resource management.

Interesting Facts

• Nepal was among the first Asian countries to prepare an SDG status report.
• Community forestry in Nepal is regarded as a global model of sustainable resource management.

Mnemonics / Memory Aids

3 Aspects of SD → “EES”

• E → Environmental
• E → Economic
• S → Social

Nepal’s Biodiversity Efforts → “N-P-C-I-C-E-R-E-I” (Think: “Nepali People Care In Conservation Every Region Every Initiative”)

• NBSAP, Protected Areas, Community Forestry, International cooperation, Climate change adaptation, Endangered species, Research, Education, Inclusive policies.

Summary / Quick Revision

• SD = development for present + future generations.
• Aspects: Environmental, Economic, Social.
• Principles: ecosystem conservation, population control, cultural & community participation.
• Importance: ensures balance between growth, equality, and environment.
• SDGs: 17 global goals (focus on 7).
• Nepal’s Efforts: policy alignment, biodiversity strategies, protected areas, community forestry, international partnerships.

Also Check Out :- Chapter 1 , chapter 2 , chapter 3