Abstract
We incorporated soil/plant biophysical properties into a simple model to predict seasonal trajectories of hydraulic redistribution (HR). We measured soil water content, water potential root conductivity, and climate across multiple years in two old-growth coniferous forests. The HR variability within sites (0 to 0.5 mm/d) was linked to spatial patterns of roots, soil moisture, and climate. The HR seasonally accounted for up to 9 percent of daily water use, peaking at 0.16 mm/d (ponderosa pine) or 0.30 mm/d(Douglas-fir), then declining as modeled pathway conductance dropped with increasing root cavitation. Patterns of HR were attributed to variability in water potential gradients and conductivity within the root system.
Keywords
Douglas-fir (Pseudotsuga menziesii),
hydraulic lift,
hydraulic redistribution,
ponderosa pine (Pinus ponderosa),
root conductivity,
soil water content,
water potential
Citation
Warren, J.M.; Meinzer, F.C.; Brooks, J.R.; Domec, J.-C.; Coulombe, R. 2006. Hydraulic redistribution of soil water in two old-growth coniferous forests: quantifying patterns and controls. New Phytologist. 173: 753-765