Brianne Palmer, Utah State University
Life Sciences
Quaking aspen (Populus tremuloides) are declining in the interior west. Aspen are critical for the maintenance of wildlife habitat and are one of the few broadleaf trees in the western forest ecosystem. In western landscapes, it has recently been determined that a large proportion of aspen trees are triploid (three copies of each chromosome) and the remaining trees are diploid (two copies of each chromosomes). In this study we attempted to find differences in the physiology between the two cytotypes to determine future management strategies The size and density of stomata trees is likely to influence the survival of the species in water- and heat-stressed environments, since stomata control both photosynthesis rates and rates of water loss. Individuals with larger stomata or greater stomatal density may be efficient photosynthesizers but may be at risk for water loss during transpiration in environments with low precipitation and hot temperatures, such as those often seen during summers in the intermountain west. To determine if there is physiological differences between the cytotypes we measured the variation between stomatal sizes and densities between the cytotypes using cellulose acetate leaf impressions and microscope imagery. We collected leaves from twelve aspen stands (eight diploid and four triploid) representing the two cytotypes in Swan Flats and Fish Lake, Utah. From these analyses, we deduced that the variation in stomatal size and density is primarily among clones rather than among cytotypes. Further data collection and analyses will occur in the spring of 2015.