The role of leaf inclination, leaf orientation and plant canopy architecture in soil particle detachment by raindrops

Abstract

A laboratory investigation of the effect of plant architecture on soil particle detachment by rainfall is described. The effects of leaf inclination, leaf orientation, effective canopy area, leaf area index, leaf subcatchment area, lowest canopy area, largest canopy area, canopy overlap area and an alternative leaf area index are examined using artificial plants. Detachment from a 30 cm diameter splash cup filled with sand (150 μm-1 mm particle size) was measured under three types of plant (small leaved, broad leaved and long narrow leaved) for a 10 minute simulated rainstorm of 75 mm/h intensity. There were no significant differences in soil particle detachment between the three plant types or between detachment under the plants and detachment of bare soil. No significant relationships were obtained between detachment and any of the plant parameters. Soil particle detachment by leaf drips can offset any protective effects of the canopy so that detachment does not differ significantly from that on bare soil. Plant architecture significantly affected the distance from the plant stem at which detachment was concentrated even though the canopy diameters of the plants were similar. There would appear to be no advantages in a detailed description of plant architecture and its effects in process-based models of soil erosion. Parameters such as plant height and plant canopy area are sufficient descriptors for modelling plant effects. Copyright © 2005 John Wiley & Sons, Ltd.