[Campbell Biology P.1220] The 'INTERPRET THE DATA' section states that some arctic tundra eco... | Practice Question

The 'INTERPRET THE DATA' section states that some arctic tundra ecosystems receive as little rainfall as deserts but have much more dense vegetation. What climatic factor, other than precipitation, is most likely responsible for this difference in vegetation density?

  • A: Higher average wind speeds in deserts.
  • B: Higher average humidity in deserts, leading to less water stress.
  • C: Lower average temperatures in the tundra, leading to less evaporation and more available soil moisture.
  • D: Greater sunlight intensity in deserts, promoting faster plant growth.

Explanation

Despite receiving similar low amounts of precipitation, arctic tundra ecosystems have much lower average temperatures than deserts. These low temperatures significantly reduce the rate of evaporation from the soil and plants, meaning that the limited water available remains in the ecosystem for longer and is more accessible to plants. In deserts, high temperatures lead to rapid evaporation, quickly depleting any available moisture.