Slope effects on the spatial variations in duff moisture


C. Valeo, Mechanical Engineering, University of Victoria, Victoria, BC, V8W 3P6, Canada.



Investigations were made on the influence of slope on the spatial variations in duff moisture, the decomposing organic matter of the forest floor. Relationships between duff and soil moisture along hillslopes were identified from field measurements over various moisture conditions. Results indicated that duff moisture is not related to soil moisture, nor is it controlled by a hydraulic gradient. The spatial pattern of duff moisture over a 2 week period was established along two 2 m by 60 m hillslope transects that were sampled every 3 m. Because of interception, tree proximity was found to be the primary factor that significantly influenced the spatial variation in duff moisture. As the duff dried, the influence of tree proximity decreased. The distance from the top of the hillslope was not found to be an important factor in duff moisture variability. The spatial variation in duff moisture is more prominent during periods of wetness because of the exponential nature of the duff drying curve. Copyright © 2011 John Wiley & Sons, Ltd.