Gas exchange of aspen, grown in elevated concentrations of carbon dioxide and (or)ozone.
Poster: Global Change
177: Gas exchange of aspen, grown in elevated concentrations of carbon dioxide and (or)ozone.
Sőber, Anu , email@example.com||Additional|
|McDonald, Evan (C) Sober, Jaak (B) Kubiske, Mark (C) Karnosky, David F (B) |
(A): University of Tartu, Institute of Botany and Ecology|
(B): Michigan Technological University
(C): USDA Forest Service North Central Research Station
A simple model for scaling up the gas exchange from leaf level to stand level is proposed for aspen (Populus tremuloides. The model is using experimental data of (i)nitrogen distribution within the leaf area of the stand, (ii)correlation between photosynthesis and area-based leaf nitrogen concentration, and (iii)data of leaf area index (LAI). The model was applied to describe changes in carbon dioxide uptake by stands of two aspen clones. These clones were grown in elevated concentations of carbon dioxide and (or)ozone in "ASPEN FACE" experiment (Rhinelander, WI). The uptake of carbon dioxide by 4-year old aspen trees was increased by elevated concentrations of carbon dioxide and decreased by elevated concentrations of ozone. The amplitude of these changes and also interaction of effects of two gaseous pollutants differed in different clones. The mechanisms of these differences are discussed.