FORESTRY
FOREST ECOLOGY AND ECOSYSTEMS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Lichens decompose organic matter from animals and plants
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Lichens begin to break down rock to form soil
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Lichens are nitrogen fixing bacteria
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None of the above
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Detailed explanation-1: -When lichens die, they decompose, adding small amounts of organic matter to the rock to make soil.
Detailed explanation-2: -The first species to colonize bare rock are usually lichens. In primary succession, they are thus the pioneer organisms. Before they can colonize an environment, many organisms need soil. Acids that break down the rock and start the process of soil formation are secreted by lichens that colonize bare rock.
Detailed explanation-3: -This process is called primary succession. It begins with organisms such as lichens that can live and grow very slowly on bare rock. Lichens (see the Fungi station) break down rock by secreting acids. The freeze-thaw cycle of winter also contributes to rock destruction.