宁夏东部风沙区沙化草地土壤水分和植被的空间特征  

Spatial characteristics of soil moisture and vegetation in desertification grassland in eastern Ningxia sand-wind area, China

作　　者：郭艳菊 马晓静 许爱云 史佳梅 刘万龙 许冬梅[1] GUO Yanju;MA Xiaojing;XU Aiyun;SHI Jiamei;LIU Wanlong;XU Dongmei(School of Agriculture Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学农学院,银川750021

出　　处：《生态学报》2022年第4期1571-1581,共11页Acta Ecologica Sinica

基　　金：宁夏自治区重点研发计划项目(2018BEG03007);宁夏高等学校一流学科建设(草学学科)项目(NXYLXK2017A01)。

摘　　要：土壤水分作为土壤-植被-大气连续体的关键因子,对沙化草地的演化过程具有重要作用。为探讨宁夏东部风沙区沙化草地土壤水分、物种丰富度指数及植被盖度的空间变异及其相互关系,以哈巴湖自然保护区沙化草地为对象,采用样线法自潜在沙化草地至重度沙化草地进行植被调查和土壤取样,通过经典统计学和地统计学分析,得出以下结果:0—100 m各土层土壤水分含量、植被盖度和物种丰富度指数的分布范围分别为0.82%—28.22%、41.00%—93.00%和0.82—2.80,变异系数范围为0.20—0.48,均属于中等变异。各土层土壤水分和物种丰富度指数表现为中等的空间自相关性,植被盖度则表现为强烈的空间自相关性。Kriging插值结果表明,0—100 cm各土层土壤水分和植被盖度的空间插值图呈条带状和斑块状的梯度变化,物种丰富度呈斑块分布,自潜在沙化草地至重度沙化草地,表现为逐渐降低的趋势。相关分析表明,植被盖度与0—40 cm各土层土壤水分呈显著正相关,与40—100 cm各土层土壤水分呈极显著正相关。宁夏东部风沙区沙化草地土壤水分含量总体较低,由于结构因素和随机因素的共同作用,随草地沙化程度的加重,表现为逐渐降低的梯度变化过程中出现局部升高的斑块格局,受土壤水分的影响,草地植被呈现出类似的空间分布特征。研究结果可为草地沙化演变过程的定量化测度及干旱风沙区草地生态环境保护和建设提供理论依据。Soil moisture is of crucial importance for hydrological, biological and biogeochemical processes, especially in arid and semiarid regions where water is the main factor limiting vegetation survival and economic development. In order to explore the spatial variability and their relationship with soil moisture, Margalef richness index and vegetation coverage of the desertified grassland in eastern Ningxia sand-wind area, three 3.6 km parallel transects were laid out from the potential desertified grassland to the severe desertified grassland with 500 m interval between the two adjacent transects. Along each transect, quadrats were established at 200 m intervals for the vegetation investigation and soil sampling. Soil samples were collected at the following depths: 0—10, 10—20, 20—30, 30—40, 40—50, 50—60, 60—70, 70—80, 80—90, and 90—100 cm. The soil moisture, Margalef richness index and vegetation coverage were measured and their spatial distributions and interrelationships were analyzed by combining of the classical and geostatistical methods. The results showed that the vegetation coverage, species richness and the contents of soil moisture at each soil layer from 0—100 cm ranged from 41.00%—93.00%, 0.82—2.80, and 0.82%—28.22%, respectively, and the variation coefficient ranged from 0.20 to 0.48, all of which belonged to moderate variability. The optimal models of the soil moisture at 0—10 cm layer and Margalef richness index were Spherical and Exponential models, respectively. The Gaussian models are applicable to the soil moisture of each layer at 10—100 cm depth. The determination coefficients ranged from 0.593 to 0.941. The nugget coefficient for the soil moisture in each layer and Margalef richness index were 26.31%—41.86%, which means the spatial heterogeneity caused by structural factors and random factors plays a major role in the soil moisture in each layer and Margalef richness index. The nugget coefficients of vegetation coverage was 2.50%. The nugget coefficients of ve

关 键 词：沙化草地 土壤水分 植被盖度 物种丰富度指数 空间特征 

分 类 号：S812.2[农业科学—草业科学]