黄土高原植被建设与土壤干燥化:问题与展望

黄土高原大规模植被建设有效减少了水土流失、改善了区域生态环境,大规模人工植被种植也造成了土壤水分的过度消耗,导致了土壤干燥化,成为当前黄土高原生态恢复的重要制约因素,威胁区域生态系统健康与稳定。系统综述了黄土高原地区人工植被恢复对土壤干燥化的作用机制,植被群落特征与土壤干燥化的耦合关系,多尺度土壤干燥化时空分异规律及其影响因素,明确了当前大规模人工植被恢复过程中土壤水分持续利用面临的问题与挑战。建议今后加强植被动态对水文过程影响的研究,明确多尺度植被格局与土壤干燥化时空分异的耦合关系,系统开展变化环境下不同尺度植被与土壤水分相互作用的模拟研究,探讨基于植被格局优化的土壤水分调控机制,维护黄土高原地区土壤安全,提升区域生态系统服务功能。

Effects of large-scale re-vegetation on soil desiccation in the Loess Plateau: problems and perspectives

Large-scale re-vegetation of the Loess Plateau has been effective in decreasing serious soil erosion and improving the local environment. The human-introduced vegetation has become the main vegetation type in this region. However, large-scale human-introduced vegetation excessively consumes soil water. Soil desiccation is now observed across the entire Loess Plateau, and has become an important limitation for ecological restoration in this critical region, where it threatens the health and stability of regional ecosystems. In this paper, we summarize the role of human-introduced vegetation on soil desiccation in the Loess Plateau; present our analysis of the spatial and temporal variability of soil desiccation and the effect of associated factors on scales from the hillslope to regional level; discuss the coupling relationships between plant community features, soil properties, topographical features, and soil desiccation; and identify the problems and challenges of sustainable utilization of soil water under the influence of large-scale vegetation restoration in the Loess Plateau. We suggest that future studies should focus on the role of vegetation dynamics in hydrological processes. We also emphasize that subsequent studies should seek to clarify the coupling relationships between multi-scale vegetation patterns and spatial and temporal variations in soil desiccation, as well as conducting simulation studies on the spatial and temporal variability of soil desiccation at different scales. Methods of decreasing soil desiccation based on vegetation pattern optimization at different scales can provide reasonable and effective approaches to sustaining vegetation restoration and enhancing soil security in the Loess Plateau.