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以位长江上游的大渡河流域的壤塘县为研究区。基于TM遥感影像,采用面向对象与目视解译相结合方法,提取1989年和2009年两个时期亚高山针叶林的空间分布,并对两期数据叠加分析,查找出其演替发生的类型和空间位置,作为因变量样本。同时,以GIS技术为支撑,基于DEM和专题数据,提取高程、坡度、坡向正弦、坡向余弦、地表曲率、距居民点距离、距耕地距离和距道路距离8个自变量,使之与亚高山针叶林空间演替样本进行Logistic回归拟合,计算各自变量的贡献率和演替发生概率在空间上的变化特征。结果表明:亚高山针叶林向草甸演替的过程中,距居民点距离和距耕地距离两个变量贡献较大,距居民点距离减小1个单位,其转变为草甸的概率将增大1.15倍。在亚高山针叶林向落叶阔叶灌丛演替的过程中,坡向正弦和距居民点距离贡献较大,其发生概率随坡向朝北程度的增大而增大,增大1个单位,概率将增大1.2倍。对亚高山针叶林空间演替特征的定量分析可以为亚高山针叶林的保护与恢复提供科学依据。
In the upper reaches of the Yangtze River Dadu River Basin Rangtang County for the study area. Based on the TM remote sensing images, the spatial distribution of the subalpine coniferous forest in 1989 and 2009 was extracted by a combination of object-oriented and visual interpretation. The data of two phases were superimposed and analyzed to find out their succession Type and spatial position as a dependent variable sample. At the same time, taking the GIS technology as the support, based on the DEM and thematic data, the authors extracted the eight independent variables of elevation, slope, slope to the sine, slope cosine, curvature of the surface, distance from residential area, distance from cultivated land and distance from the road, Logistic regression fitting was performed on the spatial succession samples of subalpine coniferous forests to calculate the spatial variation of the contribution rate and successional probability of each variable. The results showed that during the succession of the subalpine coniferous forest to the meadow, the distance from the residential area and the distance from the cultivated land contributed greatly, and the distance from the residential area decreased by 1 unit. Increase 1.15 times. During the succession of the subalpine coniferous forest to the deciduous broad-leaved shrubland, the slope to the sine and the distance from the residential area contributed greatly. The probability of occurrence increased with the increase of the degree toward the north, increasing by 1 unit. The probability will increase 1.2 times. Quantitative analysis of the spatial succession characteristics of the subalpine coniferous forest can provide a scientific basis for the protection and restoration of the subalpine coniferous forest.