Sediment yield on a devastated hill in southern China: effects of microbiotic crust on surface erosion process

摘要: In southern China, most of the forests consist Pinus massoniana, but they are usually poor, thin, and deteriorated due to human intervention such as cutting, removal litter for fuel over-grazing. Therefore, exposed bare soil is found in many devastated hills. As a consequence, both direct runoff percentage sediment yield very high. order understand surface erosion processes this environment, we measured depth terms catchment scale, carried out situ sprinkling experiments, focusing on spatial variability conditions sources. The results measurements at end headwater suggest following characteristic. (1) water capable transporting more material than supplied by detachment. That is, discharge process detachment-limited. experiments indicate that: (2) lower part hillslope where covered microbiotic crust, ratio rainfall high, small. (3) upper there no low, large. Measurements depths (4) Microbiotic crusts provide high degree protection against erosion, even though large hillslope. Consequently, almost zero (5) main source was Based these indications, it can be concluded that when detachment-limited, effect crust and/or vegetation cover great. variation controls sediment.