Atmospheric CO2 enrichment can increase the 18O content of leaf water and cellulose: paleoclimatic and ecophysiological implications

Abstract

The δ18O values of daytime total leaf water and leaf cellulose in yellow-poplar Liriodendron tulipifera (Magnoliaceae) were elevated c 2‰ when exposed to ambient + 300 μmol mol-1 CO2 in outdoor open-top chambers relative to ambient CO2 concentrations. In growth chambers, δ18O values of total leaf water during the light cycle were also enriched in a drought-stressed, 700 μmol mol-1 CO2 atmosphere treatment with limited changes in humidity. In both experiments, no significant differences were observed among treatments in δD values of leaf water in ambient or elevated CO2. -from Authors