Biogeography is a branch of geography that examines the distribution of plants, animals, and other living organisms across different regions of the Earth and the factors responsible for these distribution patterns. It combines principles from geography, ecology, biology, and environmental science to understand how living organisms interact with their physical environment.
NDA & CDS 2 2026 Exam GK – Geography – Biogeography
Biogeography helps explain why certain species are found in specific areas, how ecosystems develop, and how environmental changes influence biodiversity. It plays a crucial role in conservation planning, climate change studies, and sustainable resource management.
Meaning and Scope of Biogeography
The term “Biogeography” is derived from three Greek words: bios (life), geo (earth), and graphein (to describe). Thus, biogeography literally means the study of the geographical distribution of life on Earth.
The scope of biogeography includes:
- Distribution of plants and animals.
- Evolution and migration of species.
- Biodiversity patterns across regions.
- Ecosystem functioning and ecological interactions.
- Effects of climate change on species distribution.
- Conservation of endangered species and habitats.
Branches of Biogeography
1. Phytogeography
Phytogeography deals with the geographical distribution of plants. It studies plant communities, vegetation types, and the environmental factors influencing plant growth.
2. Zoogeography
Zoogeography focuses on the distribution of animals across different regions and examines how climate, landforms, and evolutionary processes affect animal populations.
3. Historical Biogeography
This branch investigates how geological events such as continental drift, mountain formation, and glaciations have influenced species distribution over time.
4. Ecological Biogeography
Ecological biogeography studies the relationship between living organisms and their present-day environment, including climate, soil, and water availability.
Factors Affecting the Distribution of Organisms
Climatic Factors
Climate is the most important factor influencing the distribution of plants and animals.
- Temperature
- Rainfall
- Humidity
- Sunlight
- Wind patterns
Physiographic Factors
Physical features of the Earth’s surface affect habitat conditions.
- Mountains
- Plateaus
- Plains
- Rivers
- Oceans
Soil Factors
Different soil types provide varying nutrients and moisture levels that influence vegetation growth.
Biological Factors
Interactions among organisms such as competition, predation, symbiosis, and human activities shape species distribution.
Historical and Geological Factors
Continental drift, volcanic activity, glaciation, and evolutionary history have significantly influenced present-day biodiversity patterns.
Biogeographical Realms of the World
Scientists divide the Earth into major biogeographical realms based on the distribution of flora and fauna.
1. Nearctic Realm
- Covers North America.
- Home to bison, bears, and coniferous forests.
2. Neotropical Realm
- Includes Central and South America.
- Rich in tropical rainforests and biodiversity.
3. Palearctic Realm
- Covers Europe, North Africa, and northern Asia.
- Characterized by temperate forests and grasslands.
4. Ethiopian (Afrotropical) Realm
- Includes Sub-Saharan Africa.
- Famous for elephants, lions, giraffes, and diverse wildlife.
5. Oriental Realm
- Covers South and Southeast Asia.
- Rich in tropical forests and unique species such as tigers and Asian elephants.
6. Australian Realm
- Includes Australia, New Guinea, and nearby islands.
- Known for marsupials such as kangaroos and koalas.
7. Antarctic Realm
- Covers Antarctica and surrounding islands.
- Dominated by penguins, seals, and cold-adapted organisms.
Biomes of the World
A biome is a large ecological region characterized by specific climate conditions and vegetation.
Major Terrestrial Biomes
- Tropical Rainforest
- Tropical Savanna
- Desert
- Temperate Grassland
- Temperate Deciduous Forest
- Mediterranean Vegetation
- Coniferous Forest (Taiga)
- Tundra
Aquatic Biomes
- Freshwater Ecosystems
- Marine Ecosystems
- Estuaries
- Coral Reefs
Biogeography of India
India is one of the world’s megadiverse countries due to its varied climate and topography.
Major Biogeographic Zones of India
- Trans-Himalaya
- Himalaya
- Desert
- Semi-Arid Region
- Western Ghats
- Deccan Plateau
- Gangetic Plain
- North-East India
- Islands
- Coasts
The Western Ghats and Eastern Himalayas are recognized as global biodiversity hotspots.
Importance of Biogeography
- Helps understand biodiversity patterns.
- Supports wildlife conservation and habitat management.
- Assists in environmental impact assessments.
- Provides insights into climate change effects.
- Aids in sustainable development planning.
- Helps identify biodiversity hotspots and endangered species.
Contemporary Issues in Biogeography
Climate Change
Rising temperatures and changing rainfall patterns are altering species distribution and ecosystem stability.
Habitat Destruction
Deforestation, urbanization, and industrialization threaten natural habitats.
Invasive Species
Non-native species often disrupt local ecosystems and biodiversity.
Biodiversity Loss
Human activities are causing rapid extinction of species worldwide.
