Massachusetts Comprehensive Assessment System (MCAS) Biology Practice Test

What effect does burning trees have on the nutrient cycle?

1. It increases water retention in the soil

2. It releases carbon dioxide more rapidly

3. It enhances nutrient availability

4. It has no effect on the nutrient cycle

The correct answer is: It releases carbon dioxide more rapidly

Burning trees primarily releases carbon dioxide rapidly due to the combustion of organic matter present in the wood and leaves. During this process, carbon stored in the trees is converted into carbon dioxide, a greenhouse gas, which significantly contributes to atmospheric carbon levels. This release of carbon dioxide not only impacts the carbon cycle by adding more carbon to the atmosphere but can also influence climate change and global warming. The other options do not accurately reflect the direct effects of tree burning. For instance, while soil nutrients can initially be enhanced after burning due to the release of minerals from the ash, this is often temporary and accompanied by depletion of organic matter over time. Additionally, burning does not increase water retention in soil and has a significant overall effect on the nutrient cycle by disrupting established ecosystems. Therefore, the release of carbon dioxide is the most immediate and direct impact of this process.