Rainfall, slopewash (the erosion of soil particles), surface
runoff, and fine-litter transport were measured in tropical
wet forest on a hillslope in the Luquillo Experimental Forest,
Puerto Rico, from February 1998 until April 2000. Slopewash data were collected using Gerlach troughs at eight plots,
each 2 square meters in area. Earthworms were excluded by
electroshocking from four randomly selected plots. The other
four (control) plots were undisturbed. During the experiment,
earthworm population in the electroshocked plots was reduced
by 91 percent. At the end of the experiment, the electroshocked plots had 13 percent of earthworms by count and
6 percent by biomass as compared with the control plots.