黄土高原西部退耕地植被演替与土壤水分互馈机制研究

The vegetation restoration and reconstruction of abandoned farmlands in Western Loess Plateau face the contradiction between water consumption of vegetation and soil water supply, the understanding of the feedback mechanism between vegetation succession and soil water is the key to solve the contradiction. The fund project takes soil-plant systems under nature restoration and artificial restoration with different abandoned time as the research object. The interaction between vegetation growth and soil water is the starting point. By the research on effects of vegetation succession on soil water and the response of plant growth to the soil water environment,the aim of this study is to explicit the temporal and spatial variation of soil water factors and the succession rule of vegetation, compare the differences in the two recovery process. Based on the quantitative analysis of the relationship and interaction between soil water factors and plant functional traits, the relation model between them will be established. It will reveal the feedback mechanism between vegetation succession and soil water. The results can provide theoretical basis for solving the contradiction between water consumption of vegetation and soil water supply. This research achievement will promote the sustainable development of the vegetation construction of abandoned farmlands in Western Loess Plateau.

黄土高原西部退耕地植被恢复面临植被耗水与土壤供水的矛盾，认识植被演替与土壤水分的互馈机制是解决矛盾的关键。本项目以不同退耕年限自然恢复和人工恢复的土壤-植被系统为研究对象，以植被生长与土壤水分的相互作用为切入点，开展植被演替的土壤水分效应，植被生长对土壤水分环境变化的响应研究；阐明土壤水分因子的动态变化特征，植被群落的演替规律，比较两种恢复方式下的差异；通过定量分析土壤水分因子与植被功能性状的关系和相互作用，建立二者的关系模型。揭示退耕地植被演替与土壤水分的互馈机制，为解决植被耗水与土壤供水的矛盾提供理论依据。研究成果将推动黄土高原西部退耕地植被建设的可持续发展。

黄土高原西部退耕地植被恢复面临植被耗水与土壤供水的矛盾，认识植被演替与土壤水分的互馈机制是解决矛盾的关键。本项目以不同退耕年限自然恢复和人工恢复的土壤-植被系统为研究对象，以植被生长与土壤水分的相互作用为切入点，开展了植被演替的土壤水分效应，植被生长对土壤水分环境变化的响应研究，揭示了退耕地植被演替与土壤水分的互馈机制。结果表明：土壤水分含量和渗透性能是显著影响该区域退耕地植被群落变化的主要土壤因子，植被地上生物量和水分利用率是决定土壤水分含量的关键因子。退耕初期，土壤水分对植被恢复和群落演替的作用要大于植被恢复和群落演替对土壤水分的作用，以土壤水分为主的土壤环境动态变化影响着植被功能性状的变化。随着植被群落演替的进行，植被对环境的适应能力不断增强，植被群落逐渐开始以自己的方式改变着土壤水分和养分，并逐步达到稳定。当这种相互作用达到一定程度时，植被演替的进行不再依赖于土壤水分环境的改变。该研究成果为解决植被耗水与土壤供水的矛盾提供了理论依据，并将推动黄土高原西部退耕地植被建设的可持续发展。