生态恢复背景下黄土丘陵区土壤抗冲性基本规律研究

This project is going to take soil anti-scourability as the key index to systematically investigate the soil anti-erosion ability in the loess hilly region in south of Ningxia under a background of ecological restoration. This project will establish a standard of measuring and calculating for soil anti-scourability which is suitable for the loess hilly region by large-scale sampling and experiment. On the basis of the standard, the general rules of differences of soil anti-scourability impacted by several ecological restoration measures such as level trench afforestation, artificial grassland, and natural recovery will be studied. The temporal variation of soil anti-scourability through seasons, one year and years, and the spatial variation occurred at different places in a watershed influenced by different restoration measures will be deeply investigated. This study will demonstrate the coupling relationship between the temporal-spatial variation of soil anti-scourability and the process of ecological restoration, and reveal the extent, process and mechanism of soil anti-erosion ability impacted by ecological restoration on a small scale. The results of this study will reinforce the methodological foundation for research of soil anti-scourability in loess hilly region, demonstrate the rules of temporal-spatial variation of soil anti-scourability in a watershed of loess hilly region under a background of ecological restoration, and provide straightforward and practical measures for valuation of profits derived from soil and water conservation related to ecological restoration projects, and for the innovative design and reasonable arrangement of ecological restoration measures.

本项目以土壤抗冲性为核心指标，拟对生态恢复背景下宁夏南部黄土丘陵区的土壤抗侵蚀能力进行深入系统研究。本项目拟通过大规模的野外采样和系统实验，建立适用于黄土丘陵区土壤抗冲性的测定和计算标准，并在此基础上研究水平沟整地造林、人工草地建植、天然封育等几种主要的生态恢复措施对土壤抗冲性影响差异的总体规律，深入探究不同生态恢复措施影响下的土壤抗冲性在季节、一年及多年时间跨度下随时间发生的变化，以及在小流域不同地貌部位上发生的空间变异。本研究将阐明黄土丘陵区土壤抗冲性的时空变异与生态恢复进程的耦合关系，揭示微小尺度上土壤抗侵蚀能力受生态恢复影响的程度、过程和机理。研究结果将夯实黄土丘陵区土壤抗冲性研究的实验方法基础，并探明生态恢复背景下黄土丘陵区小流域内土壤抗冲性的时空变异规律，为研究区生态恢复工程的水土保持效益评价、生态恢复措施的创新设计与合理配置提供直观的、实用的理论与技术手段。

土壤抗冲性是反映土壤抗侵蚀能力及综合健康状况的重要指标之一。但长期以来没有标准研究方法，制约了土壤抗冲性研究的深入开展。本项目通过大规模野外采样及室内测定，建立了适用于黄土丘陵区土壤抗冲性测定的优化方法，开发了配套的测定装置。在此基础之上，对研究区天然林地、人工林地、天然草地、人工草地等不同生态恢复方式下0~30cm层次土壤的抗冲性、土壤团聚体分布等状况进行了实验测定。结果显示在多数恢复方式下，土壤抗冲性随着土层深度增加而降低，且空间变异性极大。天然草地表层土壤抗冲性最高，但表层之下急剧下降。某些林地表层之下土壤的抗冲性反而高于表层。仅从土壤抗冲性提高的角度而言，天然恢复草本植被是最经济、最有效的生态恢复方式。本研究所取得的理论和技术成果有望指导黄土区以及其他地区土壤抗冲性研究的规范化开展，并为小流域水土流失治理、边坡防护等领域提供技术支撑。本项目出版专著2部，发表论文5篇，申报专利9项，截至目前获批4项，1人入选宁夏国内引才“312”计划，取得了比较丰硕的研究和人才培养成果。