古尔班通古特沙漠流动沙丘土壤水分与地形—植被因子关系  

The Relationship Between Soil Moisture and Topographic-Vegetation Factors in Mobile Dune in Gurbantunggut Desert

作　　者：张艳花 张定海[1] 马钰 王艳莉 石亚飞 Zhang Yanhua;Zhang Dinghai;Ma Yu;Wang Yanli;Shi Yafei(Institute of Quantitative Biology,College of Science,Gansu Agricultural University,Lanzhou 730070,China;College of Forestry,Gansu Agricultural University,Lanzhou 730070,China;College of Grass Industry,Gansu Agricultural University,Lanzhou 730070,,China)

机构地区：[1]甘肃农业大学理学院数量生物研究所,兰州730070 [2]甘肃农业大学林学院,兰州730070 [3]甘肃农业大学草业学院,兰州730070

出　　处：《水土保持研究》2024年第5期182-191,共10页Research of Soil and Water Conservation

基　　金：国家自然科学基金项目(42361016);甘肃省科技创新计划“西部之光”人才计划项目(22JR9KA032);甘肃农业大学青年导师扶持资助项目(GAU-QDFC-2023-07);甘肃省科技计划项目(21JR7RA831);重点研发计划—农业领域(23YFNA0036)。

摘　　要：[目的]确定沙漠沙丘土壤水分的分布规律,明确土壤水分与各个地形与植被因子间的关系,进而为沙漠地区的植被保护和重建提供科学合理的建议。[方法]以古尔班通古特沙漠流动沙丘为研究对象,在小尺度上研究了不同深度(表层0—40 cm,中层40—200 cm和深层200—300 cm)、不同微地貌(迎风坡、背风坡、丘顶和丘底)上土壤水分的分布特征(描述性统计);并采用广义线性、广义加性和随机森林模型研究了土壤水分与地形—植被因子间的关系。[结果](1)不同深度下迎风坡与丘底上的土壤水分高于背风坡与丘顶;表层土壤水分在背风坡(包括丘顶和丘底)与迎风坡上有显著性差异。(2)地形因子对土壤水分的影响大于植被因子;影响表层土壤水分的主要因子是坡度与坡向,影响中层和深层土壤水分的主要因子是灌木盖度。(3)随机森林模型的拟合效果显著高于广义线性和广义加性模型。[结论]地形因子对古尔班通古特沙漠流动沙丘不同微地貌上土壤水分的影响较植被因子大,坡度和坡向对表层土壤水分具有重要影响,灌木盖度对中层和深层土壤水分具有重要影响。[Objective] The aims of this study are to determine the distribution pattern of soil water in desert dunes,to clarify the relationship between soil water and various terrain and vegetation factors,so as to provide scientific and reasonable suggestions for the protection and reconstruction of vegetation in desert areas.[Methods] There were four different micro-landforms,including windward slope,leeward slope,hill top and bottom.The soil moisture was divided into surface(0—40 cm),middle(40—200 cm) and deep(200—300 cm) layers.The distribution characteristics of soil water on different micro-landforms and depths in Gurbantunggut Desert were studied on the small scale.Generalized linear model,generalized additive model and random forest were used to study the relationship between soil moisture and topographic-vegetation factors.[Results](1) The soil moisture on the windward slope and the bottom of the hill was higher than that on the lee slope and the top of the hill at different depths.There were significant differences of surface soil moisture between the lee slope(including the top and bottom of the hill) and the windward slope.(2) The effect of topographic factors on soil moisture was greater than that of vegetation factors.The main factors affecting surface soil water were slope and slope direction.The main factors affecting middle and deep soil water was shrub cover.(3) The fitting effect of the random forest was significantly higher than that of the generalized linear model and generalized additive model.[Conclusion] As for soil moisture on different micro-landforms,topographic factors have a greater impact on mobile dunes in Gurbantunggut Desert than vegetation factors.Slope and slope direction have the important influence on surface soil moisture.Shrub cover has a major effect on middle and deep soil moisture.

关 键 词：土壤水分 微地貌 流动沙丘 随机森林 古尔班通古特沙漠 

分 类 号：S152.7[农业科学—土壤学]