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Effects of mosaic-pattern shrub patches on runoff and sediment yield in a wind-water erosion crisscross region

Lu, Rong, Liu, Yi-Fan, Jia, Chao, Huang, Ze, Liu, Yu, He, Honghua, Liu, Bing-Ru, Wang, Zhan-Jun, Zheng, Jiyong, Wu, Gao-Lin
Catena 2019 v.174 pp. 199-205
Artemisia, canopy, landscapes, microhabitats, rain, regression analysis, runoff, sandy soils, sediment yield, sediments, shrubs, soil quality, vegetation, water erosion
Shrub patch fragmentation makes a substantial contribution to soil erosion in sandy regions. This study aimed to analyze the effects of mosaic-pattern shrub patch size on runoff and sedimentation in a wind-water erosion crisscross region. The influence of shrub patch size on runoff and sedimentation, and on several soil physical and vegetation factors was evaluated in a sandy Chinese landscape. Based upon the canopy diameter of Artemisia ordosica, a xerophytic shrub, three different patch sizes were set as the treatments, such as small (Ø < 60 cm), medium (60 < Ø < 160 cm) and large (Ø > 160 cm) shrub patches. Bare land served as control conditions. Three runoff plots were established for each shrub size, and runoff (Q) and sediment (SY) yields were monitored under natural rainfall conditions. The results indicated that rainfall distribution was uneven in the study area. Low-intensity (0–5 mm/h) and short-duration (0–5 h) rainfall events accounted for 82.6% and 71.7% of all events, respectively, during the 6-month test period, from May to October 2016. Linear regression indicated that Q and SY increased with increasing rainfall depth at the slope scale. The impact of rainfall erosion on bare land was the greatest. Compared with control plots, Q and SY reduction owing to the small, medium, and large shrub patches was 19.7% and 49.3%, 31.4% and 62.4%, and 35.9% and 94.9%, respectively. These results confirmed the different effects of shrub patches of different sizes on soil quality, runoff and sediment reduction. Besides, this study suggested that shrub patches could modify soil microhabitats on sandy soils, reducing the soil erosion rates and as well as favoring vegetation regeneration.