荒漠绿洲过渡带泡泡刺灌丛沙堆形态特征及其空间异质性

以甘肃省金塔和临泽的荒漠绿洲过渡带为研究区，定量分析了戈壁和沙漠生境中泡泡刺灌丛沙堆的形态特征、形态参数间的关系、空间格局以及空间异质性．结果表明：泡泡刺灌丛沙堆呈凸起的独立型沙包，在金塔有严重的风蚀现象．沙漠生境的沙堆高度、体积和植被冠幅的平均值均大于戈壁，其中金塔沙漠最大，其平均值为1．43m、65．19m^3和94．06m^2临泽沙漠植被高度和盖度的平均值均大于戈壁，且其最大平均值为0．48m和0．55，金塔却相反．沙堆长短轴间、沙堆体积和植被冠幅间呈显著线性关系；沙堆高度和面积、植被高度和盖度间具线性关系．沙堆沿丘间低地呈带状分布和斑块状格局．在金塔和临泽的戈壁中泡泡刺灌丛沙堆空间相关性较强，而金塔沙漠属于中等程度，临泽沙漠存在由随机的原因形成变异为主的可能性．此外，沙堆空间异质性由结构原因形成的变异为主，以临泽戈壁最高，临泽沙漠最小，金塔的戈壁和沙漠位于二者之间．

Morphological characteristics and spatial heterogeneity of Nitraria sphaerocarp nebkhas in desert-oasis ecotone

Taking the desert-oasis ecotone in Jinta and Linze of Gansu Province as study area,this paper studied the morphological characteristics of Nitraria sphaerocarp Nebkhas in the habitats of Gobi and desert,with the relationships among the morphological parameters,spatial pattern,and spatial heterogeneity analyzed quantitatively.The results showed that the N.sphaerocarp nebkhas was of convex and independent type,and obviously wind-eroded in Jinta.The average values of N.sphaerocarp nebkhas's height,volume,and plant canopy diameter were 1.43 m,65.19 m3 and 94.06 m2,respectively,being larger in desert than in Gobi,and the maximum values were in Jinta's desert.The average values of the plant height and coverage in Linze desert were larger than those in Gobi,while those in Jinta were in adverse,with their maximum values being 0.48 m and 0.55,respectively.There were significant linear relationships between the long axis and short axis,and between the volume and plant canopy diameter of the nebkhas.The relationships between the height and area,and between the volume and plant canopy diameter were both linear.N.sphaerocarp nebkhas showed zonary distribution and patchy patterns along interdune.The spatial correlation of nebkhas in the Gobi of Jinta and Linze was comparatively strong,while that in Jinta's desert was moderate.There was the possibility that the spatial heterogeneity was chiefly resulted by the stochastic reason in Linze's desert.The spatial heterogeneity of N.sphaerocarp nebkhas was mostly derived from the variation formed by the structural reason.The spatial heterogeneity was the highest in Linze's Gobi and the lowest in Linze's desert,while that in Jinta's Gobi and desert was between the formers.