Atmospheric CO2 has been increasing rapidly since the late 1800s, largely due to human activities. Recall that CO2 enters leaves through stomata and can then be used for photosynthesis. However, transpiration occurs as a result of water evaporating through stomata. How have plants responded to elevated CO2 levels? Assuming that the CO2 level continues to increase with time, how likely are plants to be able to continue to adapt by adjusting stomatal conductance?

Verified step by step guidance

1. Understand the relationship between CO2, stomata, and photosynthesis: CO2 enters plant leaves through small openings called stomata, where it is used in photosynthesis to produce glucose and oxygen. The same stomata also allow for transpiration, the process of water vapor exiting the plant, which can lead to water loss.
2. Recognize the plant response to elevated CO2 levels: In response to higher atmospheric CO2 concentrations, many plants reduce the number and/or opening size of their stomata. This adaptation decreases water loss through transpiration without significantly affecting the intake of CO2 for photosynthesis, thus improving water use efficiency.
3. Consider the implications of continued CO2 increase: If atmospheric CO2 levels keep rising, plants may continue to adjust by further reducing stomatal conductance. However, this adaptation has limits based on the species and environmental factors such as temperature, humidity, and water availability.
4. Evaluate the likelihood of ongoing adaptation: The ability of plants to continue adapting to increasing CO2 levels by adjusting stomatal conductance will depend on the rate of CO2 increase and the specific environmental conditions. Rapid changes may outpace the ability of plant species to adapt, potentially stressing plants.
5. Explore potential research and implications: Further research is needed to understand the full range of plant responses to elevated CO2 levels across different ecosystems and climates. Understanding these mechanisms can help predict plant behavior under future climate scenarios and guide agricultural and conservation strategies.