Leaf conductance of four species growing in a subarctic marsh

Abstract

This paper describes measurements of leaf conductance made with a diffusion porometer on four wetland species growing in a coastal marsh on James Bay. The measurement period covered most of the growing season. In general, leaf conductance for the sedge, Carex paleacea, was larger than for three woody species, Alnus rugosa, Salix bebbianna, and Salix discolor. No distinct pattern was observed in maximum conductance throughout the growing season; however, leaf conductance demonstrated distinct diurnal trends for all species. The response of leaf conductance to various environmental variables was examined and it was found that conductance of all species was most strongly related to the atmospheric vapour pressure deficit. Two models for predicting leaf conductance from environmental variables showed moderate success.