Which statement does NOT describe an effect on the carbon cycle when humans clear-cut forests?

• A. The amount of carbon dioxide in the atmosphere decreases significantly.
• B. Less carbon is stored in plant biomass.
• C. The rate of photosynthesis in the area decreases.
• D. More carbon dioxide is released due to decomposition of plant material.

Answer: (A)

Verified step by step guidance

1. Understand the carbon cycle: The carbon cycle involves the movement of carbon between the atmosphere, organisms, and the Earth. Plants play a key role by absorbing carbon dioxide (CO₂) during photosynthesis and storing it in their biomass.
2. Analyze the effects of clear-cutting forests: When forests are clear-cut, the number of plants decreases, which reduces the rate of photosynthesis. This means less CO₂ is absorbed from the atmosphere, and less carbon is stored in plant biomass.
3. Consider decomposition: After clear-cutting, plant material left behind decomposes. Decomposition releases CO₂ back into the atmosphere, contributing to an increase in atmospheric carbon dioxide levels.
4. Evaluate the statement about atmospheric CO₂: The statement 'The amount of carbon dioxide in the atmosphere decreases significantly' does NOT align with the effects of clear-cutting forests. Instead, clear-cutting typically leads to an increase in atmospheric CO₂ due to reduced photosynthesis and increased decomposition.
5. Conclude the reasoning: The other statements ('Less carbon is stored in plant biomass,' 'The rate of photosynthesis in the area decreases,' and 'More carbon dioxide is released due to decomposition of plant material') accurately describe effects of clear-cutting on the carbon cycle, making the first statement the correct answer to the question.