What Is a Biome?
Biomes are broad ecological regions defined largely by climate and characteristic organisms. Understanding biomes helps students connect temperature, precipitation, vegetation, biodiversity, and ecological organization.
What Is a Biome?
What Is a Biome?
A biome is a large geographic region characterized by particular climate conditions and characteristic types of organisms. Temperature and precipitation are especially important in determining the characteristics of terrestrial biomes.
Biomes are much larger than individual ecosystems. A single biome can contain many different ecosystems that share broad climatic conditions and characteristic vegetation.
Biome = large region defined largely by climate and characteristic life. A biome contains many ecosystems.
Why Is Climate So Important?
Climate strongly influences which organisms can survive in a region. Temperature affects rates of biological processes and the ability of organisms to tolerate environmental conditions. Precipitation determines how much water is available to plants and other organisms.
Because plants form the foundation of many terrestrial food webs, climate-driven vegetation patterns strongly influence the animals and other organisms that can live in a biome.
Major Terrestrial Biomes
Terrestrial biomes are broad land regions with characteristic climate and vegetation. Common examples include tropical rainforests, deserts, temperate forests, grasslands, and tundra.
Tropical Rainforest
High temperatures and abundant precipitation support dense, highly productive vegetation and high biodiversity.
Desert
Low precipitation limits plant growth. Organisms often have adaptations for conserving or obtaining water.
Temperate Forest
Moderate precipitation and seasonal temperature changes support forests with distinct seasonal patterns.
Tundra
Very low temperatures and a short growing season limit vegetation; permafrost is characteristic of many Arctic tundra regions.
Grassland
Seasonal precipitation and frequent disturbance such as fire or grazing can favor grasses over dense forests.
What About Aquatic Biomes?
Aquatic environments are commonly grouped into freshwater and marine systems. Freshwater systems include lakes, ponds, rivers, and streams. Marine systems include oceans, coral reefs, estuaries, and other saltwater environments.
Aquatic ecosystems are strongly influenced by factors such as salinity, depth, light availability, temperature, dissolved oxygen, nutrient availability, and water movement.
When a question describes salinity, depth, dissolved oxygen, or water movement, it may be focusing on aquatic ecosystem conditions rather than a terrestrial biome.
Biome vs. Ecosystem
A biome is a broad geographic category based largely on climate and characteristic organisms. An ecosystem is a biological community interacting with its abiotic environment.
Why Are Biomes Distributed Where They Are?
Global patterns of temperature and precipitation help explain the distribution of terrestrial biomes. Latitude, elevation, proximity to oceans, and atmospheric circulation all influence local climate.
That is why similar biomes can occur in geographically separated regions. A desert does not have to be one continuous area, and a temperate forest can occur in different parts of the world where similar climate conditions exist.
Common Misconceptions
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Quick Practice
1. What is a biome?
2. What two climate factors are especially important in determining terrestrial biomes?
3. What is the difference between a biome and an ecosystem?
4. Can two separate regions have the same biome type?
5. Name two major terrestrial biomes.
Key Takeaways
- A biome is a large geographic region characterized by climate and characteristic organisms.
- Temperature and precipitation are especially important in determining terrestrial biomes.
- A biome contains many ecosystems.
- Terrestrial biomes include tropical rainforests, deserts, temperate forests, grasslands, and tundra.
- Aquatic systems include freshwater and marine environments.
- Biome and ecosystem are different ecological scales.
- Similar biomes can occur in geographically separated regions when climate conditions are similar.
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