Chandler, K.R., and Chappell, N.A. 2008 Influence of individual oak (Quercus robur) trees on saturated hydraulic conductivity. Forest Ecology and Management. in press.
The influence of single trees on saturated hydraulic conductivity (Ks) was investigated for six isolated oak trees (Quercus robur) growing on a Dystric Gleysol in an area of parkland in northwest England. The Ks was measured within the A soil horizon over a 0.10 to 0.25 m depth using a borehole permeameter.
A dataset of 119 Ks values was obtained and comprises of 55 values from around one oak tree at distances of 1 to 13 m from the trunk, 45 tests around five other oak trees and 19 tests in open grassland. For the intensively sampled tree, Wilcoxon rank sum tests showed a significant difference (p < 0.05) between the Ks at 3, 5, 7 and 11 m from the trunk and that in the surrounding grassland. Geometric mean Ks 3 m from this tree was 3.35 x 10-6 m s-1, a factor of 3.4 higher than that in the surrounding open grassland. Mean Ks decreased at a rate of -4 x 10-7 m s-1 per m up to 9 m from the trunk, though it increased at 11 m, before declining again. Similar patterns were observed in the 45 values from the five other oak trees.
A literature review of the potential positive and negative effects of trees on Ks was used to provide tentative explanations for the observed patterns and highlights new data needed.
To send me a mail message: