摘要
[目的]探究高寒草甸退化秃斑地土壤风蚀规律,为退化草甸区的植被恢复和生态环境保护提供科学依据。[方法]选取青海省河南县因高原鼠兔活动而退化形成的秃斑地作为研究对象,在9,12,15 m/s这3种风速条件下,对不同植被覆盖度(0%,20%,40%,60%,80%)的退化秃斑地进行原位模拟风力侵蚀试验,以分析植被盖度在不同风速下对土壤风蚀的影响。[结果]①退化秃斑地的土壤风蚀速率随时间推移呈现先急剧下降后趋于平缓的变化趋势(p<0.05)。在总时长为60 min的风蚀试验下,前10 min是土壤风蚀速率变化的敏感期。②3种风速下,植被盖度与总输沙量之间均呈显著负相关的指数函数关系(R^(2)=0.98),其指数系数绝对值越大,表明植被覆盖度对风蚀的抑制作用随风速增加而减弱。③随着植被盖度的增加,0~5 cm高度范围内输沙量显著降低,且各植被盖度的输沙量均随高度增加而逐渐减少。[结论]增加植被盖度能够有效降低风蚀速率和输沙高度,但在较高风速下,植被盖度对风蚀的抑制效果显著减弱,且植被盖度抑制土壤风蚀的关键阈值在40%左右,并随着植被盖度的持续增大,风蚀减少的边际效益逐渐降低。
[Objective]The law of soil wind erosion in degraded bare patches in alpine meadows was examined to provide a scientific basis for vegetation restoration and ecological and environmental protection in degraded meadow areas.[Methods]Bare patches degraded by plateau pika activity in Henan County,Qinghai Province,China were selected as research subjects.In-situ wind erosion simulation experiments were conducted under three wind speeds of 9,12,and 15 m/s for degraded bare patches with different vegetation cover levels(0%,20%,40%,60%,and 80%)to investigate the effects of vegetation cover on soil wind erosion under varying wind speeds.[Results]①The soil wind erosion rate for degraded bare patches showed a trend of initially sharp decline followed by stabilization over time(p<0.05).During the 60 min wind erosion experiment,the first 10 min was the sensitive period for changes in the soil wind erosion rate.②Under all three wind speeds,there was a significant negative exponential relationship between vegetation cover and total sediment transport(R^(2)=0.98).The larger the absolute value of the exponential coefficient,the weaker the inhibitory effect of vegetation cover on wind erosion at higher wind speeds.③As vegetation cover increased,the sediment transport within the 0—5 cm height range significantly decreased,and sediment transport at all vegetation cover levels gradually decreased with increasing height.[Conclusion]Increasing vegetation cover can effectively reduce wind erosion rates and sediment transport heights.However,at higher wind speeds,the inhibitory effect of vegetation cover on wind erosion significantly weakened.The critical threshold for vegetation cover to inhibit soil wind erosion was approximately 40%.As vegetation cover continued to increase,the marginal benefits of reducing wind erosion gradually diminished.
作者
越大林
李国荣
童生春
隆玉翔
朱海丽
刘亚斌
李进芳
赵健赟
李希来
胡夏嵩
Yue Dalin;Li Guorong;Tong Shengchun;Long Yuxiang;Zhu Haili;Liu Yabin;Li Jinfang;Zhao Jianyun;Li Xilai;Hu Xiasong(Department of Geological Engineering,Qinghai University,Xining,Qinghai 810016,China;Key Laboratory of Cenozoic Resource&Environment in Northern Margin of the Tibetan Plateau,Xining,Qinghai 810016,China;State Key Laboratory of Three-River Source Ecology and Plateau Agriculture and Animal Husbandry,Qinghai University,Xining,Qinghai 810016,China)
出处
《水土保持通报》
北大核心
2025年第3期36-46,共11页
Bulletin of Soil and Water Conservation
基金
青海省科技厅基础研究项目“国家公园黄河源区高寒草原土壤风蚀机理研究”(2021-ZJ-701)
国家自然科学基金项目“多维立体观测下黄河源鼠兔干扰与高寒草甸退化的耦合关系研究”(42161068)。
关键词
高寒草甸
高原鼠兔
植被盖度
退化秃斑地
土壤风蚀
alpine meadow
plateau pika
vegetation cover
degraded bare patches
soil wind erosion
