Question

1. how do human activities, like deforestation, affect the carbon and nitrogen cycles?

Explanation:

Deforestation reduces plants that absorb carbon dioxide (carbon cycle) and disrupts soil nitrogen - related processes (nitrogen cycle).

Answer:

Deforestation affects the carbon cycle by reducing the number of trees that can absorb carbon dioxide ($CO_2$) through photosynthesis. As a result, more $CO_2$ remains in the atmosphere, contributing to increased greenhouse gas levels. For the nitrogen cycle, trees play a role in the nitrogen cycle through processes like nitrogen fixation (in some tree - associated symbiotic relationships) and uptake of nitrates. Deforestation can lead to soil erosion, which may carry away nitrogen - rich soil. Also, the decomposition of remaining plant matter after deforestation can release nitrogen in a less regulated way compared to a healthy forest ecosystem.