Ren Zongping, Li Zhanbin, Liu Xiaolu, Li Peng, Cheng Shengdong, Xu Guoce
State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi'an University of Technology, Xi' an, 710048, China.
Sci Rep. 2018 Feb 14;8(1):2972. doi: 10.1038/s41598-018-21362-5.
Two contiguous watersheds in the Loess Plateau in China that differed in the way their vegetation had been restored-afforestation or natural revegetation-differed in their consumption of soil moisture: the afforested watershed consumed more soil moisture, although the difference was significant only in wet years. Yet, both the afforestation and natural revegetation did not induce the soil desiccation in the study area. In the afforested watershed, soil moisture was depleted even beyond a depth of 100 cm, whereas in the grassland (natural revegetation), the depletion was confined to a layer less than 60 cm deep. Rainfall in the growing season accounted for 46-60% of the variation in soil moisture in the 0-60 cm layer in the grassland, but only 22-39% of that in the forest land. Overall, afforestation is the better option for the Loess Plateau only in areas where the annual rainfall is more than 500 mm. In any attempt at revegetation, the choice of tree species and planting densities should match the carrying capacity of the region's water resources.
中国黄土高原上两个相邻的流域，其植被恢复方式不同（造林或自然植被恢复），土壤水分消耗情况也不同：造林流域消耗的土壤水分更多，不过这种差异仅在湿润年份显著。然而，造林和自然植被恢复均未在研究区域引发土壤干燥化。在造林流域，土壤水分甚至在100厘米以下深度也出现消耗，而在草地（自然植被恢复区域），消耗仅限于深度小于60厘米的一层。生长季降雨占草地0至60厘米土层土壤水分变化的46%至60%，但在林地仅占22%至39%。总体而言，只有在年降雨量超过500毫米的地区，造林才是黄土高原更好的选择。在任何植被恢复尝试中，树种选择和种植密度应与该地区水资源承载能力相匹配。
