Question

plants play an important role in the carbon cycle. more carbon is taken out of the atmosphere by photosynthesis than by any other process. so, areas that have lots of plants are important carbon sinks. the amazon rainforest, for example, accounts for about 25% of the co₂ absorbed on land. each year, many acres of rainforest are cut down. this clearing of the rainforest, or deforestation, affects the carbon cycle. how does deforestation affect the carbon cycle? complete the sentences. when rainforests are cleared, the amount of co₂ absorbed by plants. as the trees decompose, the amount of co₂ in the atmosphere.

Explanation:

1. For the first blank: Rainforests have many plants that absorb $\ce{CO_2}$ via photosynthesis. When deforestation occurs, the number of plants (trees) that can absorb $\ce{CO_2}$ decreases. So the amount of $\ce{CO_2}$ absorbed by plants will decrease.
2. For the second blank: When trees are cut down and decompose (or are burned, which is often part of deforestation processes), they release the carbon they stored (in the form of $\ce{CO_2}$). So as the trees decompose, the amount of $\ce{CO_2}$ in the atmosphere will increase.

Answer:

When rainforests are cleared, the amount of $\ce{CO_2}$ absorbed by plants decreases. As the trees decompose, the amount of $\ce{CO_2}$ in the atmosphere increases.