Seasonal Changes in the Photosynthetic Capacity of Populus Tremuloides Bark

Abstract

Changes in the photosynthetic capacity of two Populus tremuloides clones were measured using bark slices. The photosynthetic capacity of one clone (E S) declined during the winter and increased during spring and early summer. The spring increase was associated with a rise of chlorophyllcontent. A second clone (E P) retained a high photosynthetic capacity throughout the year. It was estimated that 5 to 10 percent of the total photosynthetic capacity of the tree resides in the bark. Considering only the stem, bark photosynthesis may reutilize 50 to 75 percent of the CO 2 released through respiration of stem tissues. Forest Sci. 17:308-313.