Ron Ryel has been Assistant Professor of Plant Physiological Ecology in USU's Department of Wildland Resources for the past four years. He received his PhD from University of Wuerzburg (Germany) in Plant Physiological Ecology, and his MS from USU in Wildlife Ecology. He has worked with water relations in Great Basin plants for past 20 years, and has worked specifically on aspen the past 3 years.

Abstract:
Water relations and water yield in aspen and conifer forests

Ron Ryel and Eric LaMalfa, Department of Wildland Resources, Utah State University, Logan, UT 84322-5230

Aspen decline in the Intermountain West is associated with changes in resources values. Reduction in water yield with the conversion of aspen to conifer has been one hypothesized change that has important implications for water resources in these semi-arid lands. Hypothesized mechanisms include differential accumulation of snow, melting patterns, and plant water use rates. We evaluated these mechanisms to assess the potential for differences in water yield with conversion of aspen stands to conifer. Our results indicate significant differences in water accumulation in the peak snow pack as the most likely mechanism to result in changes in water yield. These differences could have profound effects on both watershed water yield and on ecosystem function. Potential ecological consequences of restoring aspen to increase watershed water yield are discussed.