摘要
土壤水分是沙漠植被的主要驱动因子,其分布受到地形、植被和气候之间相互作用的影响。以腾格里沙漠东南缘沙坡头地区流动沙丘上不同深度不同微地貌上的土壤水分作为研究对象,研究了土壤水分和地形-植被因子的分布特征。利用广义线性、广义加性和随机森林模型在小尺度上对因子关系之间进行分析建模。结果表明,(1)不同深度的4种微地貌中土壤水分呈现出丘底和迎风坡上的土壤水分显著高于背风坡,而背风坡又显著高于丘顶。(2)地形因子(主要指坡向)和植被因子对不同深度的土壤水分均具有重要的影响。其中,地形因子对表层和中层土壤水分的影响高于深层土壤水分,植被因子(主要指草本多度和生物量)对中层和深层土壤水分的影响高于地形因子。
Soil moisture,which is the main driver of desert vegetation,is influenced by the interaction between topography,vegetation,and climate in terms of its distribution.Taking the Shapotou area of the southeastern edge of the Tengger Desert as the research object,the distribution characteristics of soil moisture and topographic-vegetation factors of the mobile sand dunes at different depths and micro landforms were studied.Then,generalized linear,generalized additive,and random forest models were used to analyze and simulate the relationship between factors at a small scale.The results showed that the order of soil moisture at different depths on the four micro-topographies could be sorted as hilltop>windward slope>leeward slope>hilltop.Topographic factors(mainly the slope aspect)and vegetation factors had important effects on soil moisture at different depths.Among them,topographic factors showed more significant influences on surface and middle soil moisture than the deep soil moisture.Whereas,the vegetation factors(mainly herbaceous abundance and biomass)showed a more significant influence on soil moisture in the middle and deep layers than the topographic factors.
作者
王昱婷
张定海
宁婷
叶彦辰
Yuting Wang;Dinghai Zhang;Ting Ning;Yanchen Ye(Institute of Quantitative Biology,College of Science,Gansu Agricultural University,Lanzhou,Gansu,730070,China)
