Biogeography is an important branch of Geography that studies the distribution of living organisms—both plants and animals—across the Earth’s surface. It explains how physical environment, climate, soil, and geographical barriers influence biodiversity. For NDA and CDS aspirants, understanding biogeography is essential for topics related to natural vegetation, wildlife, and ecological balance.
NDA & CDS 1 2026 Exam Geography – Biogeography
Branches of Biogeography
Biogeography can be divided into the following main branches:
- Plant Geography (Phytogeography):
Focuses on the distribution of plant species, their adaptation to environment, and types of natural vegetation found in different regions. - Animal Geography (Zoogeography):
Studies the global and regional distribution of animal species, migration patterns, and ecological habitats. - Ecological Geography:
Examines how environmental conditions such as temperature, rainfall, altitude, and soil affect the life forms of a region. - Palaeobiogeography:
Deals with the distribution of ancient flora and fauna as revealed through fossils, helping in understanding continental drift and evolution.
Factors Affecting Distribution of Organisms
- Climatic Factors:
Temperature, precipitation, humidity, and sunlight directly affect the type of vegetation and animal life in a region.- For example, dense tropical rainforests grow in equatorial regions due to high rainfall and temperature.
- Soil Factors:
The fertility and mineral content of soil influence plant growth, which in turn determines animal habitat.- Black soil supports cotton cultivation, while alluvial soil supports rice and wheat.
- Topography:
Mountains, plains, and plateaus determine vegetation type. Higher altitudes have alpine vegetation, while plains support dense forests or grasslands. - Geographical Barriers:
Deserts, oceans, and mountains act as natural barriers that prevent migration of species, leading to unique regional biodiversity. - Human Activities:
Deforestation, urbanization, and agriculture alter the natural habitat and affect biodiversity patterns.
Major Biogeographic Realms of the World
The world is divided into six major biogeographic realms based on the distribution of animals and plants:
- Nearctic Realm – North America
- Palearctic Realm – Europe, North Asia, and North Africa
- Neotropical Realm – South America and parts of Central America
- Ethiopian Realm – Africa (excluding North Africa) and Madagascar
- Oriental Realm – South Asia and Southeast Asia (including India)
- Australian Realm – Australia and surrounding islands
Biogeographic Zones of India
According to the Wildlife Institute of India (WII), India is divided into 10 biogeographic zones, each with unique flora and fauna:
| Zone | Examples of States/Regions | Characteristics |
|---|---|---|
| Trans-Himalayan | Ladakh, Lahaul-Spiti | Cold deserts, sparse vegetation |
| Himalayan | Uttarakhand, Himachal Pradesh, Sikkim | Alpine forests, rich biodiversity |
| Desert | Rajasthan, Kutch | Xerophytic vegetation, arid climate |
| Semi-Arid | Punjab, Gujarat | Grasslands and thorn forests |
| Western Ghats | Kerala, Maharashtra | Evergreen forests, high rainfall |
| Deccan Peninsula | Madhya Pradesh, Chhattisgarh | Dry deciduous forests |
| Gangetic Plain | Uttar Pradesh, Bihar | Fertile alluvial soil, dense population |
| North-East India | Assam, Meghalaya | Tropical rainforests, high biodiversity |
| Coastal | Eastern and Western coasts | Mangroves, coconut and cashew vegetation |
| Islands | Andaman-Nicobar, Lakshadweep | Coral reefs, tropical vegetation |
Importance of Biogeography
- Helps in biodiversity conservation and wildlife management.
- Aids in understanding ecosystem balance and environmental planning.
- Provides insights into evolution and migration of species.
- Useful for agriculture, forestry, and land-use planning.
- Supports efforts toward climate change adaptation and sustainable development.
Conclusion
Biogeography connects life with the Earth’s physical environment. For NDA and CDS aspirants, studying this topic provides a scientific understanding of how ecosystems function and evolve. Knowing the distribution of flora and fauna across various biogeographic regions also strengthens environmental and geography-related sections of the examination.
