Certified Arborist Practice Exam

This occurs when trees take up carbon from CO2 in the atmosphere and "store" it in the form of wood and other carbon-based tissues:

1. Carbon sequestration

2. Nutrient cycling

3. Photosynthesis

4. Transpiration

The correct answer is: Carbon sequestration

The term that describes the process by which trees absorb carbon dioxide from the atmosphere and convert it into carbon-based materials such as wood is carbon sequestration. This is an important ecological function, as it helps reduce the concentration of CO2 in the atmosphere, which can mitigate climate change. During this process, trees use photosynthesis to turn CO2 and sunlight into energy, which they then store in various forms, including their trunk, branches, and leaves. While photosynthesis is certainly involved in the initial uptake of carbon, it specifically refers to the biochemical process that allows trees to convert CO2 into energy and glucose; thus, it is a part of carbon sequestration rather than synonymous with it. Nutrient cycling relates more to the movement of nutrients through the ecosystem and does not specifically focus on carbon storage in trees. Transpiration involves the loss of water vapor from plants and does not pertain to carbon storage or uptake. Overall, carbon sequestration is the most appropriate term that encapsulates the entire ongoing process of trees storing carbon over time.