Spatial heterogeneity and temporal stability of throughfall under individual Quercus brantii trees

Spatio-temporal patterns of throughfall (TF) have often been studied under forest canopies. Few reports, however, have been made on small-scale TF variability in deciduous forest stands. In the present research, the spatial heterogeneity and temporal stability of TF under five individual persian oak trees (Quercus brantii var. Persica) was quantified. The research site was in the Zagros forests in western Iran, where mean annual precipitation and temperature are equal to 587.2mm and 16.9 degrees C, respectively. Data from 23 rainfall events were aggregated to assess the spatial correlation of TF. Variograms for TF beneath two of the five trees reached a stable sill at the range of 5-6m. The redistribution of TF within the canopy was highly variable in time, attributable to seasonal variation in canopy foliation and meteorological factors. As the length of the sampling period increased, the spatial variability of TF decreased and the temporal stability of the TF pattern increased. Time stability plots of TF normalized with respect to mean and variance showed a moderate general persistence for all individual trees. We conclude that single trees modify the spatial distribution of TF reaching the forest floors. Copyright (c) 2012 John Wiley & Sons, Ltd.