Atmospheric CO2 concentration is expected to increase and scientists have long considered how this will affect plants. The general theory is that plant water use will decline as an increase in CO2 means stomata do not have to open as far or for as long to uptake the same amount of CO2 for photosynthesis. While this outcome has been found to be the case for many plant species the entire story, as always, is a lot more complex.
Two new cases studies have just been posted onto the ICT International website which delve into this topic in more detail.
The first case study, Elevated CO2 and Plant Water Use, discusses how elevated CO2 has a different effect on plant water use depending on whether water use is measured at the leaf (stomatal conductance with the SC-1 Leaf Porometer), stem (as measured with the SFM1 Sap Flow Meter), or whole tree scale.
The second case study, CO2 and Hydraulic Conductivity, discusses how leaf specific hydraulic conductivity is related to transpiration and how very little research is available which has explicitly studied CO2 effects on plant hydraulic conductivity.