Interception losses in grassy vegetation

Studies of the interception process in grassy species are reported for a series of laboratory tests. Procedures, equipment, and techniques were developed to determine the magnitudes of rainfall interception on grasses and to measure the resultant losses. It was found in vigorously growing grass plots that the evaporation of a given amount of intercepted moisture was accompanied by a like reduction in the amount of evapotranspiration from the plants. Total moisture use was approximately the same in plots with wet and dry leaf surfaces. The interception storage component and precipitation passing through the vegetative canopy as combined stemflow, throughfall and drip (STD) were measured to determine the relationships and magnitudes. Storage capacities were observed to agree essentially with those reported by other investigators although some variations can occur with different storm types and intensities. Values of STD were found to be quite significant even at the beginning of small storms.