放牧和刈割对大针茅草原羊草空间异质性的影响  

Effect of grazing and moving on spatial heterogeneity of Leymus chinensis in stipa grandis steppe

作　　者：郑佳华 张峰 赵天启 赵萌莉 ZHENG Jiahua;ZHANG Feng;ZHAO Tianqi;ZHAO Mengli(College of Grassland,Resource and Environment,Inner Mongolia Agricultural University,Hohhot,Inner Mongolia 010010,China)

机构地区：[1]内蒙古农业大学草原与资源环境学院,内蒙古呼和浩特010010

出　　处：《西北农林科技大学学报（自然科学版）》2020年第6期10-17,共8页Journal of Northwest A&F University(Natural Science Edition)

基　　金：国家自然科学基金项目(31861143001)。

摘　　要：【目的】分析不同利用方式下小尺度羊草种群的空间异质性及其分布,为草地的可持续利用提供参考。【方法】以大针茅典型草原优势种羊草为研究对象,基于地统计法,利用变异函数、空间自相关系数、分形维数以及克里格插值法,分析放牧、刈割和围封(对照)利用方式下羊草种群空间异质性的变化。【结果】放牧可显著提高羊草种群密度(P<0.05),3种利用方式下羊草种群密度均值表现为放牧(48.38株/m^2)>围封(12.53株/m^2)>刈割(7.51株/m^2)。不同利用方式下,羊草种群空间分布的最优模型均为球状模型,羊草种群空间异质性表现为围封>放牧>刈割,羊草种群的空间分布格局主要受结构性因素的影响。在围封样地中,羊草种群呈现出较小尺度内变异较大的带状分布;在放牧样地中,羊草种群呈现出较大尺度内变异较小的片状分布;在刈割样地中,羊草种群以变异性大的高密度点状斑块镶嵌于平坦的低密度斑块上,呈现点状分布。【结论】放牧和刈割对大针茅草原羊草种群密度和空间异质性均有影响。【Objective】This study analyzed the spatial heterogeneity and distribution of Leymus chinensis populations at small scales under different utilization regimes.【Method】The dominant species of L.chinensis in typical grassland of stipa grandis was taken as the research object.Based on statistical method,the spatial heterogeneity changes of leymus chinensis population under different utilization regimes of grazing(G),mowing(M)and enclosure(CK)were analyzed using variogram,spatial autocorrelation coefficient,fractal dimension and kriging interpolation method.【Result】Grazing significantly increased the density of L.chinensis population(P<0.05)and the density of L.chinensis population was in the order of grazing(48.38 individuals/m 2)>enclosed(12.53 individuals/m 2)>mowing(7.51 individuals/m 2).The optimal spatial distribution model of L.chinensis populations under different utilization regimes was spherical model.The spatial heterogeneity of L.chinensis population was in the order of enclosed>grazing>mowing.The spatial distribution pattern of L.chinensis population was mainly affected by structural factors under three different utilization regimes.In the enclosed plot,L.chinensis populations showed a band-like distribution with large variation within small scales.In the grazing plot,L.chinensis populations showed a patchy distribution with less variation within larger scales.In the mowing plot,L.chinensis population showed a point-like distribution of high-density point-like patches with large variability embedded in flat low-density patches.【Conclusion】Grazing and moving had impacts on population density and spatial heterogeneity of L.chinensis.

关 键 词：羊草种群 草地利用 空间异质性 地统计学 克里格插值法 

分 类 号：S812.8[农业科学—草业科学]