Over the past 150 years, our industrial society - by burning coal, oil, and gasoline - has increased the amount of carbon dioxide (CO2) in the atmosphere; CO2 levels are predicted to continue to increase in the next 50-100 years. This research project will determine how this increase in CO2 will affect the way plants take up water from the soil. Normally, plants take in CO2 through small pores on their leaves, but in the process they lose water to the atmosphere. When the amount of CO2 increases in the atmosphere, plants respond by closing these pores, reducing the amount of water lost, and reducing amount of water plants take up from the soil. However, the consequences for water cycling in soil are unknown. This research will determine whether increasing CO2 affects the amount of water plants take up from the soil, the depth in the soil at which plants take up water, and the consequences of these changes for other soil water cycling.
