Heidi Asbjornsen of the University of New Hampshire will present "Assessing the Ecohydrological Effects of Land Use Change Across Multiple Scales: From Leaves to Watersheds" on Wednesday, April 18, at 3:30 p.m. in the Hardin Hall auditorium. Her talk is part of the Spring 2012 Water Seminar Series, organized and sponsored by the Nebraska Water Center, part of the Daugherty Water for Food Institute (http://waterforfood.nebraska.edu/), with support from Institute of Agriculture and Natural Resources and School of Natural Resources.
Abstract
Understanding how cycling and fluxes of water through vegetation influences watershed processes such as runoff and streamflow is critical to managing landscapes for multiple ecosystem services. Several examples illustrate how linking ecophysiological measurements about plant water relations and hydrological data about watershed response at different scales can help elucidate these relationships. In agricultural landscapes of Central Iowa, integration of perennial strips into watersheds dominated by annual rowcrops of corn and soybean was found to modify plant transpiration, depth of plant water uptake, and soil moisture dynamics in ways that enhance regulation of the hydrologic flows at the watershed scale. In a cloud forest zone of Veracruz, Mexico, patterns of plant water use are tightly coupled to fog climatology, resulting in both suppressed transpiration and foliar water absorption in response to fog events, which in turn, impact water balance and streamflow at the forest stand to watershed scale. Recent work in the Northern Hardwood Forests of New Hampshire is revealing the effects of forest structure on stand transpiration, while preliminary findings suggest direct linkages between changes in nutrient availability, climate fluctuations, and plant water use patterns. The potential for using stable isotopes to further examine ecohydrological effects of land use and climate change, with an emphasis on plant water cycling, is also explored.