兴安落叶松林径级分布格局及其关联性

Spatial Distribution Patterns and Associations of Diameter Class in Larix gmelinii in Cold-temperate Zone Forest

基于大兴安岭1.05 hm2兴安落叶松原始林样地调查数据,采用点格局分析法的O-ring统计,分析兴安落叶松原始林不同径阶的空间分布格局及其空间关联性,探讨形成原因及动态变化趋势。结果表明:林分主要由兴安落叶松(Larix gmelini)和白桦(Betula platyphylla)组成,伴生少量山杨(Populus davidiana),林分整体及3个树种的直径结构呈倒"J"型分布,属增长型种群。林分空间分布格局随空间尺度和林木径级的增大从聚集分布转为随机分布。兴安落叶松和白桦间的空间关联性为负相关;小径级和大径级林木的种内关联性呈负相关,而中径级与小径级、大径级之间主要表现为不相关。

With the data collected from 1.05 hm2stationary sample plot of natural forest in Daxing’ an Mountains in Inner Mongolia,we studied the spatial distribution patterns and associations of diameter class in Larix gmelinii in cold temperate zoneforest by using a point pattern analysis method of the 0ring statistic,and the reasons and the dynamic change trend. Theforest in this region mainly consists of Larix gmelini and Betula platyphylla with a bit of Populus davidiana. All the threetypes of trees are in a form of rapid growing. The distribution of diameter the three types of trees follows the shape of a reverted “ J” . As the scale and diameter of individual tree increase,the spatial distribution in the forest experiences a processof turning larger random distribution from their aggregated distribution. The spatial relationship of Larix gmelini and Betulaplatyphylla shows negative correlations. The spatial relationship of small diameter class and big diameter class shows negative correlations. The spatial relationship of middle diameter class is uncorrelated.