土壤干层发生机理及其生态环境效应是土壤物理学和生态学及其交叉领域的重要科学问题,也是我国黄土高原开展生态文明建设,实现可持续发展面临的重大生态环境问题之一。通过回顾土壤干层研究取得的重要进展,包括土壤干层的概念与特征、评价指标、形成原因与危害、不同尺度时空分异特征及调控对策等,针对黄土高原水资源短缺和植被退化现状,提出土壤干层研究面临的机遇和挑战,包括建立统一的土壤干层动力学量化指标、干层内土壤水分对植物生长的有效性、土壤干层强度对土壤—植被—大气传输体(SVATs)中水分运移的影响、土壤干层发生发展过程和时空演变规律、土壤干层预测模型及其调控机制。此外,土壤干层的研究应结合当前植被恢复与生态文明建设的国家需求。在气候变化和剧烈人类活动背景下,开展黄土高原土壤干燥化与土壤水资源影响及其调控对策研究,将是水科学与生态学领域长期面临的科学问题之一。
Studies on the formation of a Dried Soil Layer( DSL) and its effect on eco-environment are important issues of soil science as well as ecology. It is also critical for the construction of ecological civilization and the sustainable development in the Loess Plateau of China. In view of the serious shortage of water resource and to the potential degradation of restored vegetation,this paper proposed the challenge and opportunity of the research on DSL and made some recommendations for future studies on DSL. The development of dynamic indices for characterizing DSL,the availability of soil moisture in DSL to vegetation,the impact of the intensity of DSL on water transport processes in Soil-Vegetation-Atmosphere-Transfer system( SVATs),the formatting processes of DSL and its spatiotemporal patterns,and the modeling of DSL were reviewed. Based on the literature of related studies,researches on DSL were commented in this paper. They included its concept and dynamic characteristics,its quantified indices,its formation,its damages on eco-environment,its distribution on various scales and controlling factors. In addition,researches on DSL should be targeted on the goal of the national vegetation restoration and the construction of ecological civilization. With the climate change and intensive human activities,carrying out the research on the effects of soil desiccation on soil water resource and its regulation is of importance to water sciences and water resource in the region.