CHANGES IN LEAF CHARACTERISTICS OF SPECIES ALONG ELEVATIONAL GRADIENTS IN THE WASATCH FRONT, UTAH

Leaf absorptances and leaf angles were measured on 159 of the most common vascular plant species along a precipitation/elevation transect in the Wasatch Mountains. At the community level, leaf angles were steepest in the driest saltbush community sites, became progressively more horizontal in wetter communities, and reached a minimum in the midelevation mountain brush communities. At higher elevation plant communities, where growth is delayed until summer months because of heavy snowfall, leaf angles were again steeper. Leaf absorptances among all life forms were uniformly high along the entire transect until the driest saltbush communities where a number of species exhibited reduced leaf absorptances. The results are discussed within the context of mechanisms for reducing solar radiation absorption along an aridity transect.