红壤丘陵区不同植被覆盖阈值小流域时空分布规律  

Spatiotemporal Patterns of Small Watersheds with Different Vegetation Coverage Thresholds in Red Soil Hilly Region

作　　者：陈佳[1] 李忠武[2,3] 方怒放[4] 刘成 宁珂 王凌霞 CHEN Jia;LI Zhongwu;FANG Nufang;LIU Cheng;NING Ke;WANG Lingxia(College of Agriculture,Guizhou University,Guiyang 550025,China;College of Resources and Environmental Sciences,Hunan Normal University,Changsha 410081,China;College of Environmental Science and Engineering,Hunan University,Changsha 410082,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A&F University,Yangling,Shaanxi 712100,China;International Research and Training Center on Erosion and Sedimentation,Beijing 100048,China)

机构地区：[1]贵州大学农学院,贵阳550025 [2]湖南师范大学资源与环境科学学院,长沙410081 [3]湖南大学环境科学与工程学院,长沙410082 [4]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [5]国际泥沙研究培训中心,北京100048

出　　处：《水土保持研究》2023年第2期186-192,共7页Research of Soil and Water Conservation

基　　金：国家重点研究发展计划项目(2017YFC0505401);贵州大学博士基金(2021042)。

摘　　要：植被覆盖度是反映土壤侵蚀状况的关键指标,实施植被恢复是防治小流域土壤侵蚀的重要措施,但小流域植被覆盖度到底恢复到多少才能有效控制土壤侵蚀尚不清楚。基于土壤侵蚀治理的小流域植被覆盖度阈值效应,对红壤丘陵区33 157个小流域2000—2015年植被覆盖度的时空变化进行了分析,评估不同植被覆盖阈值小流域时空分布规律与格局,以期精准制定小流域土壤侵蚀治理方式与对策。结果表明:(1) 2000—2015年,84%的小流域植被覆盖呈不断增加趋势,植被覆盖下降的小流域占15%,植被覆盖度基本不变的小流域仅有1%;(2)植被覆盖小于40%(低阈值带)的小流域占比小且相对稳定(3%~7%),说明大规模人工治理小流域土壤侵蚀的局面已扭转,但耕地依然是重点关注的对象;(3)植被覆盖位于40%~80%(过渡带)的小流域占比一直最高(超过83%),应采取以“自然恢复为主,人工修复为辅”的治理方式,重点关注土地利用结构和植被结构的优化配置;(4)植被覆盖大于80%(高阈值带)的小流域占比从2010年前的1%~2%上升到2015年的14%,可见具有自我修复植被覆盖条件的小流域显著增加,实施自然恢复(如封禁)是高阈值带小流域的优先选择。Vegetation coverage is a key indicator reflecting soil erosion status. Implementing vegetation restoration is an important measure to control soil erosion in small watersheds. However, it is not clear how much vegetation coverage can be restored in small watersheds to effectively control soil erosion. Based on the threshold effect of vegetation coverage in small watersheds in soil erosion control, we analyzed the spatiotemporal changes of vegetation coverage in 33 157 small watersheds in the red soil hilly area from 2000 to 2015, and evaluated the spatiotemporal distribution patterns of small watersheds with different vegetation coverage thresholds in order to precisely formulate erosion control methods and countermeasures in small watersheds. The results show that:(1) from 2000 to 2015, the vegetation coverage of 84% of the small watersheds showed an increasing trend, vegetation coverage in 15% of the small watersheds had decreased, and vegetation coverage in only 1% of the small watersheds did not change;(2) small watersheds with vegetation coverage less than 40%(low threshold zone) accounted for small portion of the total watersheds and relatively stable(3%~7%), indicating that the situation of artificial control of soil erosion in small watersheds had been reversed, but cultivated land was still the focus of erosion control;(3) the proportion of small watersheds with vegetation cover at 40%~80%(transition zone) had been the highest(more than 83%), and the control method of ‘natural restoration as the main, artificial management as the supplement’ should be adopted, focusing on the optimal allocation of land use structure;(4) the proportion of small watersheds with vegetation cover greater than 80%(high threshold zone) increased from 1%~2% before 2010 to 14% in 2015. It showed that the small watersheds with natural restoration vegetation coverage conditions had increased significantly. The implementation of natural restoration(such as enclosure) is a preferred selection for small watersheds with high thres

关 键 词：植被覆盖度 阈值效应 土壤侵蚀 小流域 红壤丘陵区 

分 类 号：S157.1[农业科学—土壤学] S157.2[农业科学—农业基础科学]