The spatial and temporal partitioning of water has been shown to have ecological and evolutionary implications for plant water use strategies (e.g.,physiology and morphology; Cohen 1970, Walter 1979, Schwinning and Ehleringer 2001). Thus, changes in the seasonality or variability of precipitation — both predictions of most GCMs (Houghton et al.2001) — are likely to affect the distribution of soil moisture in space and time, with ramifications for the performance of species and their interactions with other organisms \citep{WELTZIN_2003}.