Question

Terrestrial biomes such as tundra, taiga, temperate forests, and tropical forests are distributed in different parts of the world. Which one of the following options best represents the environmental factors that determine the distribution of these biomes?

• A. Temperature and elevation
• B. Rainfall and wind
• C. Temperature and rainfall
• D. Fire and elevation

Hint:

Biome maps, like the Whittaker biome diagram, are built from just two climate axes.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
We are asked which pair of environmental factors decides where a terrestrial biome, such as tundra, taiga, temperate forest, or tropical forest, ends up on the map.

Step 2: Key Concept:
Ecologists classify terrestrial biomes mainly using a climate diagram (the Whittaker biome diagram) that plots mean annual temperature on one axis and mean annual rainfall (precipitation) on the other. A cold, dry climate gives tundra. A cold, somewhat wetter climate with a strong seasonal swing gives taiga (boreal forest). A warm, wet climate gives tropical forest, and a moderate climate with moderate rainfall gives temperate forest.

Step 3: Detailed Explanation:
Elevation and fire do matter locally, but they are secondary factors, they explain smaller scale patterns, like alpine zones on a single mountain or fire adapted patches within a biome, not the broad, world scale placement of the major biome types. Wind alone does not set biome boundaries the way temperature and rainfall do. So among the choices, only the pairing of temperature and rainfall captures the two axes that ecologists actually use to define and separate the world's terrestrial biomes.

Step 4: Final Answer:
Temperature and rainfall together set the broad distribution of terrestrial biomes.
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