Effects of long-term elevated CO2 on foliage characteristics of Quercus ilex L. and Juniperus communis L.

To study the effects of long-term elevated CO2 on Quercus ilex andJuniperus communis, leaves from plants growing close to a natural CO2spring and from plants at a control site were collected and analyzed.Starch concentrations in leaves were found to be higher for plantsgrowing under high CO2. Nitrogen concentrations were lower, but only inJuniperus communis. No differences in stomatal densities were found. Theresults indicate that in a CO2 -elevated environment, growth of bothspecies will be different: Quercus ilex will be able to take advantageof the higher CO2 levels in spring, whereas in both species limited sinkavailability in the middle of the growing season will result inincreased starch concentrations.