Do desert plants partition water by soil depth or time?
Schwinning, Susanne*,1, Chesson, Peter2, 1 Texas State University, San Marcos, TX2 University of Arizona, Tucson, AZ ABSTRACT- H. Walter and others hypothesized that plants in water-limited environments can coexist through the spatial partitioning of soil water, if there are sufficient differences in the rooting depths of species. Mounting evidence suggests that this mechanism of resource partitioning may not be effective in arid regions where precipitation rarely recharges deeper soil layers. An alternative to water partitioning in space is partitioning in time, facilitated through differences in the timing of water uptake and utilization. We conducted a modeling study, using a mechanistic plant-soil-atmosphere simulation model, to explore the impact of spatial resource partitioning mechanisms (facilitated by differences in root distribution) and of temporal mechanisms (facilitated by differences in phenology) on the competitive interactions of plant species in arid settings. Our resu
