Effects of land use and land cover on soil erosion control in southern China: Implications from a systematic quantitative review.

The degradation of soil resources is accelerating owing to water erosion induced by detrimental land use/land cover (LULC) practices. Although the relationship between affecting factors associated with LULC and soil erosion has been well-documented, a systematic review of LULC for erosion control is lacking. A quantitative synthesis of 1270 runoff and 1302 sediment observations from 79 references covering 57 sites was conducted to assess the effects of LULC on erosion control in the red soil hilly region (RSHR) of southern China. The results indicated that the maximum runoff and soil loss were found in bare land (BL), but the minimum runoff and soil loss were detected in cropland and grassland, respectively. Among the 16 land use subtypes, BL left for natural succession had the highest runoff, but the lowest runoff was found in orchard with contact cover; the soil loss was largest for cropland without conservation measures, while the minimum value was detected in natural shrubland. When the vegetation coverage exceeded 60%, runoff and soil loss both tended to reach a stable rate. Land use with a multi-layer vegetation structure or ground/contact cover or broadleaf plant had less runoff and lower sediment values. In addition, soil loss decreased sharply during the initial 3 y of vegetation restoration, and then slowly declined until reaching a relatively stable rate after 15 y of succession. Our results confirmed that land use (except for BL) has a limited influence on soil erosion provided that suitable land cover is established. This study revealed that sustainable land management measures should be adopted based on local conditions to reduce soil erosion induced by irrational LULC. These findings can serve as a scientific basis for policy makers and land managers with respect to water erosion control in the RSHR.