Impacts of eucalyptus (Eucalyptus exserta) plantation on sediment yield in Guangdong Province, Southern China—a kinetic energy approach

The relationship between the kinetic energy of waterdrops (rainfall and throughfall) and sediment yield (suspended solid (SS) and bed load (BL)) was studied in paired watersheds (one without vegetation and the other covered by an eucalyptus (Eucalyptus exserta) plantation) in Guangdong Province, Southern China. The results showed that there was a significant correlation between the kinetic energy of waterdrops and sediment yield in both watersheds. Sediment yield in the unvegetated watershed is significantly affected by the kinetic energy of atmospheric raindrops. Sediment yield in the plantation watershed, however, is significantly related to the kinetic energy of throughfall waterdrops, but not to the atmospheric rainfall intensity or the rainfall kinetic energy. When rainfall amount is greater than 5 mm, and their intensities are less than 20 mm h−1, the single-layer eucalyptus plantations significantly increased the kinetic energy of waterdrops to the land surface, and consequently, accelerated soil erosion. However, these plantations do have positive impacts on the reduction of soil erosion for the rainfall events of larger intensities (particularly >40 mm h−). Management implications of these results are discussed in the context of soil protection xxxxxxxxand ecosystem rehabilitation.