Major Biomes of the World

Major Biomes of the World – UPSC Biogeography Notes

Overview: A biome is a large ecological region characterized by specific climate, vegetation, and wildlife. Understanding biomes is crucial for UPSC Geography, Environment, and Ecology as it links climate patterns with biodiversity and human life.

Table of Contents

• 1. What is a Biome?
• 2. Factors Determining Biomes
• 3. Classification of Major Biomes
• 4. Characteristics of Major Biomes
• 5. Distribution of Biomes
• 6. Importance of Biomes
• 7. UPSC Quick Revision Notes
• 8. Previous Year Question

1. What is a Biome?

A biome is a large natural ecosystem defined mainly by climate, vegetation, and wildlife. Biomes extend over large geographic areas such as tropical rainforests, deserts, grasslands, and tundra.

They reflect the long-term interaction between climate, soil, plants, and animals.

2. Factors Determining Biomes

• Climate: temperature, rainfall, seasonal variations.
• Latitude: affects solar radiation and temperature.
• Soil type: nutrient availability, texture, pH.
• Relief: altitude and slope influence vegetation.
• Human activities: deforestation, agriculture, urbanization.

3. Classification of Major Biomes

The Earth’s biomes can be grouped into three main categories:

• 1. Terrestrial Biomes
• 2. Aquatic Biomes
• 3. Transitional (Mixed) Biomes

4. Characteristics of Major Biomes

1. Tropical Rainforest Biome

• Located near the equator (0°–10° latitudes).
• High rainfall (>200 cm/year) and high temperature.
• Dense evergreen vegetation.
• Highest biodiversity on Earth.
• Examples: Amazon Basin, Congo Basin, Indonesia.

2. Tropical Savanna (Grassland) Biome

• Located between 10°–20° latitudes.
• Seasonal rainfall (wet & dry seasons).
• Tall grasses with scattered trees.
• Home to large herbivores (zebras, elephants).
• Examples: East Africa, Brazil (Campos), Australia.

3. Desert Biome

• Very low rainfall (<25 cm="" li="" year="">
• High diurnal temperature variation.
• Sparse vegetation (cacti, shrubs).
• Examples: Sahara, Arabian, Thar, Atacama.

4. Temperate Grassland Biome

• Moderate rainfall (25–75 cm/year).
• Short or tall grasses depending on rainfall.
• Fertile soils (chernozems).
• Examples: Prairies, Steppes, Pampas, Veld.

5. Temperate Deciduous Forest Biome

• Found in mid-latitudes with four distinct seasons.
• Trees shed leaves in autumn.
• Examples: Eastern USA, Europe, East Asia.

6. Mediterranean Biome

• Hot dry summers and mild wet winters.
• Vegetation: evergreen shrubs, olives, cork trees.
• Examples: Mediterranean Basin, California, Chile.

7. Coniferous Forest (Taiga/Boreal Forest) Biome

• Long, cold winters and short summers.
• Coniferous trees (pine, spruce, fir).
• Examples: Canada, Alaska, Russia.

8. Tundra Biome

• Found in high latitudes (Arctic) & high mountains.
• Very cold, dry environment.
• Vegetation: mosses, lichens, grasses.
• Permafrost present.
• Examples: Alaska, Greenland, Siberia.

9. Aquatic Biomes

Divided into:

• Freshwater Biomes: rivers, lakes, ponds.
• Marine Biomes: oceans, coral reefs, estuaries.

10. Transitional (Mixed) Biomes

• Wetlands: swamps, marshes.
• Estuaries: meeting point of river freshwater & sea saltwater.
• Mangroves: salt-tolerant forests along tropical coasts.

5. Distribution of Biomes

Biome distribution is primarily determined by latitude and climate:

• Equatorial region: Tropical rainforest.
• Subtropical region: Savanna and deserts.
• Mid-latitudes: Temperate grasslands, Mediterranean, deciduous forests.
• High latitudes: Coniferous forests, tundra.

6. Importance of Biomes

• Maintain global biodiversity.
• Provide ecosystem services (oxygen, water regulation, pollination).
• Support agriculture, forestry, and wildlife.
• Help regulate climate and carbon cycles.
• Home to indigenous communities and cultures.

7. UPSC Quick Revision Notes

Biome = large ecological region with specific climate & vegetation.
Determined by climate → temp + rainfall.
Main biomes → Tropical Rainforest, Savanna, Desert, Temperate Grassland, Temperate Forest, Mediterranean, Taiga, Tundra.
Aquatic biomes → freshwater & marine.
Rainforests → highest biodiversity.
Deserts → least rainfall; high temp variation.
Taiga → largest continuous biome on land.
Tundra → permafrost; very cold.
Mediterranean → dry summer; wet winter.

8. Previous Year Question

Q. Which one of the following biomes has the highest biodiversity?
(a) Savanna
(b) Temperate forest
(c) Tropical rainforest
(d) Tundra
Answer: (c) Tropical rainforest

Related Keywords

Biomes UPSC Notes, Major Biomes of the World, Tropical Rainforest, Grasslands, Taiga, Tundra, Mediterranean Biome, Biogeography UPSC.

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Sources: NCERT Class XI – Fundamentals of Physical Geography, Goh Cheng Leong, WWF Biome Classification (simplified for UPSC).

Next Topic → Natural Vegetation and Wildlife – UPSC Geography Notes