Liu Xingting, Cai Lu, Li Mengyang, Yan Yilin, Chen Hao, Wang Fei
Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, China.
Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi, China.
Sci Total Environ. 2024 Nov 25;953:175912. doi: 10.1016/j.scitotenv.2024.175912. Epub 2024 Aug 31.
Soil moisture is a key factor for vegetation restoration in arid and semi-arid regions. Clarifying the vertical characteristics of soil moisture in artificial forests on a regional scale and its response mechanisms can benefit for land use management in water-deficient areas such as the Loess Plateau. The study targets Robinia pseudoacacia on the Loess Plateau with a meta-analysis based on 790 soil moisture data points abstracted from 35 published papers. The results show that extensive cultivation of R pseudoacacia on the Loess Plateau leads to a significant reduction in soil moisture (P < 0.05). Soil moisture decreases significantly with growth of trees, especially between 400 and 500 cm soil layers. Soil moisture increases with the hydrothermal gradient. The results indicate that intensive afforestation activities in high temperature and rainy areas still significantly consume deep soil moisture. The main reason is that the impact of hydrothermal factors on soil moisture is significant between 0 and 200 cm soil layers and decreases with increasing soil depth. However, the continuous depletion of deep soil moisture leads to insignificant differences in soil moisture responses under different topographical conditions in the region. Therefore, neglecting the impact of forest age and hydrothermal factors on soil moisture in afforestation activities, the excessive water consumption by R pseudoacacia during growth poses potential risks to the ecological environment of the Loess Plateau. This study provides references for knowledge on water relating problems and sustainable management of artificial forests in arid and semi-arid areas.
土壤水分是干旱和半干旱地区植被恢复的关键因素。在区域尺度上阐明人工林土壤水分的垂直特征及其响应机制，有助于黄土高原等缺水地区的土地利用管理。本研究以黄土高原的刺槐为研究对象，基于从35篇已发表论文中提取的790个土壤水分数据点进行荟萃分析。结果表明，黄土高原上大面积种植刺槐导致土壤水分显著降低（P<0.05）。土壤水分随树木生长显著降低，尤其是在400至500厘米土层之间。土壤水分随水热梯度增加。结果表明，高温多雨地区的密集造林活动仍会显著消耗深层土壤水分。主要原因是水热因子对0至200厘米土层土壤水分的影响显著，且随土壤深度增加而减小。然而，深层土壤水分的持续消耗导致该地区不同地形条件下土壤水分响应差异不显著。因此，在造林活动中忽视林龄和水热因子对土壤水分的影响，刺槐生长过程中过度耗水对黄土高原生态环境构成潜在风险。本研究为干旱和半干旱地区人工林水分相关问题及可持续管理的认识提供了参考。
