荒漠-绿洲过渡带斑块植被表层土壤颗粒的空间异质性

以河西走廊荒漠-绿洲过渡带为研究区域,采用土壤分析筛和地统计学的方法,对研究区典型样地斑块植被表层土壤颗粒的组成特征及其空同异质性进行了研究,结果表明：1）不同粒径范围的土壤颗粒质量含量不同,其中细砂（0.25～0.075 rmm）占总土粒质量的75.135 9％,中砂（0.5～0.25 rmm）占13.273 0％,而粗砂（d＞0.5mm）和粉砂（d＜0.075 mm）的含量相对较少,分别只占5.189 5％和6.401 6：2）不同粒径范围的土壤颗粒空间异质性不同,其中粒径1mm≥d＞0.1 mm的土壤颗粒空间异质性的99.6％～88.8％是由空间自相关因素引起的,随机因素起的作用较小,其它粒径范围的土壤颗粒空间异质性的95.1％～100％是由随机因素引起的,而空间自相关因素的作用很小;3）粒径1mm≥d＞0.1 mm的土壤颗粒含量的最优拟合理论模型为曲线模型,空间异质性尺度在24～36.3 m之间,其它粒径范围的土壤颗粒含量的最优拟合模型为线状模型或块金模型,空同异质性尺度较大,均为146.36m.研究结果为进一步探讨荒漠-绿洲过渡带土壤空同异质性与植被空同格局的关系提供依据.

Spatial Heterogeneity of Surface Soil Particles of Patch Vegetation in Desert-Oasis Ecotone

In this paper, we regard the typical plot as study are~ The plot is located in desert-oasis ecotone of Hexi Corridor in Gansu Province. The methods of soil sieve analysis and geo-statistics are applied to analyze the comtx）si- lion characteristics and spatial heterogeneity of surface soil particles of patch vegetation in the study area. The anal- ysis results reveal that： （1） The quality percentage of surface soil particle has significant difference in different soil particle size range,the particle size of soil particles is mainly in the range of 0. 25--0. 075 mm in the area,the parti- cle size range of soil particles is considered fine sands,and accounts for 75. 1359~ of total soil particle quality. Fol- lowed by medium sands,its particle size is in the range of 0. 5--0. 25 mm,and accounts for 13. 273o% of the total The coarse .sands （d~0. 5ram） and silty .sands （d,（0. 075ram） take up a smaller proportion respectively, and only occupy 5. 1895% and 6. 4016% of the total. （2） The soil particle of different particle size range has the significant spatial heterogeneity, for the soil particle size is in the range of 1--0. lmm, and the autocorrelated spatial heteroge- neity is a main component of the spatial heterogeneity with the percentage of nugget （Co）/sill （Co ＋C） varying from 0. 4 M to 11. 2 %, that is, the spatial heterogeneity is primarily caused by the spatial autocorrelation factors which accounting for 99. 6%~88. 8~ of the degree of spatial heterogeneity. But for the soil particles of other parti- cle size range, the random variance of spatial heterogeneity is a main component with the percentage of nugget （Co）/sill （Co＋C） varying from 95. 1~/60 to100%. （3） The .soil particles of particle size are in the range of 1--0. lmm, the curve model is considered as the best fitting theory model, and their spatial heterogeneity scale is relative- ly small,varying from 24m to 36. 3re,but the soil particles of other particle size range fit to linear models and nug- get model with large-scale spatial heterogeneity, and their spatial variability .scale reaches to 146. 36m This re- search results will provide scientific reference for further study in the connection between the .soil spatial heteroge- neity and the vegetation spatial pattern.