HR: 1340h
AN: H53E-0528    [Abstracts]
TI: Effect of succession after fire on species contribution to evapotranspiration in sagebrush steppe
AU: * Naithani, K
EM: kn77@uwyo.edu
AF: University of Wyoming, Department of Botany, 1000E University Ave, Laramie, WY 82071 United States
AU: Ewers, B E
EM: beewers@uwyo.edu
AF: University of Wyoming, Department of Botany, 1000E University Ave, Laramie, WY 82071 United States
AU: Pendall, E
EM: pendall@uwyo.edu
AF: University of Wyoming, Department of Botany, 1000E University Ave, Laramie, WY 82071 United States
AU: Bayless, M K
EM: meaganKB@uwyo.edu
AF: University of Wyoming, Department of Botany, 1000E University Ave, Laramie, WY 82071 United States
AB: Shrubland ecosystems play an important role in the hydrology of the often drought stricken inter-mountain basins of the United Sates. Our objective was to investigate the impact of changing environmental conditions on three major plant functional types, shrubs, grasses and forbs. We measured changes in diurnal water flux from Artemisia tridentata var vaseyana (mountain big sagebrush), Elymus smithii (western wheatgrass) and Lupinus argentus (lupine) with changing environmental drivers for a sagebrush ecosystem fire chronosequence near the Sierra Madre Mountains, Wyoming, USA. The measurements were conducted on four stands ranging in age from 2 to 38 years, during the summers of 2004 and 2005. Leaf scale measurements and shrub sapflux were compared with ecosystem scale measurements. We explained the diurnal and monthly variability of water fluxes from June through October using vapor pressure deficit, soil moisture, light and temperature. In the year 2005, peak ecosystem level evapotranspiration of 5-7 mmol m-2 s-1 was higher than 2004 with 2-3 mmol m-2 s-1. The interannual difference in evapotranspiration was explained by higher precipitation causing greater biomass, especially in non shrub species, in 2005. Our results show that environmental conditions have impacts on total evapotranspiration that depend on plant functional type.
DE: 1851 Plant ecology (0476)
DE: 4802 Anoxic environments (0404, 1803, 4834, 4902)
SC: Hydrology [H]
MN: Fall Meeting 2005