Question

how does soil form on an island that is made of cooled rock from a volcanic eruption?
soil forms when parts of the lava cool into very small rocks and dust.
soil forms from the constant movement of species in and out of the community.
soil forms when lichens and mosses grow, break down rocks, and die.
soil forms when large trees take over the community from small bushes.

Explanation:

To determine how soil forms on a volcanic island, we analyze each option:

• The first option is incorrect because cooling lava into small rocks/dust is not soil formation (soil needs organic matter and weathered rock).
• The second option is incorrect as species movement doesn't form soil.
• The third option is correct. Lichens and mosses are pioneer species in primary succession. They grow on bare rock, secrete acids to break down rock, and when they die, their organic matter contributes to soil formation.
• The fourth option is incorrect as large trees taking over is part of ecological succession but not the initial soil formation process on bare volcanic rock.

Answer:

C. Soil forms when lichens and mosses grow, break down rocks, and die.