作 者 ：刘冰,赵文智,杨荣
期 刊 ：生态学报 2008年 28卷 4期 页码：1446~1455
关键词：荒漠绿洲过渡带；灌丛沙堆；形态特征；空间异质性；柽柳；
Keywords:desert-oasis ecotone, Nebkhas, morphological characteristic, spatial heterogeneity, Tamarix ramosissima,
摘 要 ：以甘肃金塔县和内蒙古额济纳旗的荒漠绿洲过渡带为研究区，研究了戈壁和沙漠两种生境中柽柳灌丛沙堆的形态特征，定量分析了不同生境中柽柳灌丛沙堆形态参数间的关系、空间格局以及空间异质性。结果表明：(1)大部分沙堆为独立型，在沙漠生境通常沿风向形成沙堆链(额济纳NE 83°15′，金塔NE 53°13′)。沙堆高度、体积和植被冠幅的均值在戈壁生境均小于沙漠生境，植被高度和盖度的均值在戈壁生境均大于沙漠生境。此外，沙堆高度、体积和植被冠幅、高度、盖度的最大均值都出现在额济纳，依次为4.47 m、 1133.5 m3、534.5 m2、2.27 m和0.47。(2)沙堆长短轴间、体积和冠幅间均为线性关系；沙堆高度和面积间的回归曲线为抛物线；植被冠幅和高度的回归曲线在戈壁生境是抛物线，沙漠生境中却是线性关系。(3)戈壁生境中沙堆相互分隔呈斑块状格局，沙漠生境中呈沙丘链状分布。(4)空间异质性由非随机的结构原因形成的变异为主，在额济纳的空间异质性高于金塔。空间相关性在额济纳戈壁生境中较强，沙漠生境和金塔戈壁生境中属于中等程度；在金塔空间异质性存在由随机的原因形成变异为主的可能性，其环境因素对空间异质性产生大的影响。此外，结论表明高强度的风积产生较深的沙埋对柽柳灌丛生长的促进作用及灌丛与沙堆间的反馈效应是柽柳灌丛沙堆的适应性机理。
Abstract:We investigated the morphological characteristic of Tamarix ramosissima Nebkhas in two different habitats: the Gobi desert and the desert in the desert-oasis ecotones that locate in Jinta County, Gansu Province and Ejin Banner, Inner Mongolia Autonomous Region. Also, we quantitatively analyzed the relationships between the morphological parameters, spatial pattern and spatial heterogeneity. The results indicated that: (1)Most of Tamarix ramosissima Nebkhas are independent type and often form the Nebkhas chains along wind orientation in the desert (Ejin NE83 15′, Jinta NE53 13′). The average values of Nebkhas height, volume and plant canopy diameter in the Gobi desert are smaller than those in the desert, whereas the average values of plant height and coverage in the Gobi desert are all larger than those in the desert. The maximum values in Nebkhas height and volume, plant canopy diameter, height and coverage occur in Ejin, with the average value of 4.47 m, 1133.5 m3, 534.5 m2, 2.27 m and 0.47, respectively.(2)There are linear relationships between the long and short axises, and between the volume and plant canopy diameter of Nebkhas. The regression curve of Nebkhas height and area is parabolic. The regression curve of plant height and canopy diameter is parabolic in the Gobi desert or linear in the desert.(3)The Tamarix ramosissima Nebkhas show a patche distribution pattern in the Gobi desert,while they form Nebkhas chain distribution in the desert. (4)The spatial heterogeneity of Tamarix ramosissima Nebkhas is mostly derived from the variation that is caused by the non-stochastic structural reason, and the extent of spatial heterogeneity in Ejin is higher than the one in Jinta. The spatial relevance is comparatively strong in Ejin′s Gobi desert, and moderate in Ejin′s desert and Jinta′s Gobi desert.There is the possibility that the spatial heterogeneity is chiefly caused by the stochastic reason in Jinta. The spatial heterogeneity is affected by environmental factors to a great degree in Jinta. In addition, The conclusions indicated that: The adaptability mechanisms of Tamarix ramosissima Nebkhas may be the stimulative function of comparative deep sand-burial as a result of wind accumulate with high-intensity to the growth of Tamarix ramosissima Nebkhas and the feedback effect between the shrub and Nebkhas.
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