HR: 13:35h
AN: A33A-01 INVITED     [Abstracts]
TI: Toward a More Plant-Centric View of the Water Budget: A Central Conundrum for Unraveling Biosphere-Atmosphere-Hydrology Interactions
AU: * Breshears, D D
EM: daveb@ag.arizona.edu
AF: University of Arizona, 1311 E Fourth Street, Tucson, AZ 85721-0043 United States
AB: Much emphasis has recently been placed on the need to more fully integrate ecology and hydrology explicitly, which implicitly also requires more fully integrating atmospheric interactions. Although environmental scientists from different disciplines have been studying aspects for the water budget for decades or longer, partitioning of the water budget in an ecologically meaningful way remains a central challenge in addressing biosphere-atmosphere-hydrology interactions. Here I provide a plant-centric view of the water budget and highlight major research challenges, drawing on examples from semiarid woodlands. Recent studies highlight how precipitation patterns can be evaluated in a more ecologically meaningful manner. Intercepted precipitation is assumed to evaporate from plant foliage, but may be absorbed and improve plant water status. Redistribution of runoff can contribute to re-concentration of water that increases the proportion of precipitation obtained by plants. Soil water content is highly spatially heterogeneous at the scale of individual plants, but usually only vertical heterogeneity with depth is considered. A central challenge is to partition soil evaporation from plant water uptake and subsequent transpiration. The proportion of cover by woody plants in particular has large effects on biosphere-atmosphere-hydrology interactions, and hence changes in woody cover through drought, fire, thinning, and succession are of key interest. A more plant-centric view of the water budget is required to address the challenging interactions and feedbacks associated with biosphere-atmosphere-hydrology interfaces.
DE: 0315 Biosphere/atmosphere interactions
DE: 1655 Water cycles (1836)
DE: 1836 Hydrologic budget (1655)
DE: 1851 Plant ecology
DE: 1866 Soil moisture
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly