宝天曼栎类天然次生林主要树木种群结构及空间分布格局

以宝天曼国家级自然保护区正在恢复过程中的栎类天然次生林作为研究对象,通过每木定位,并利用MAPGIS7.0对坐标信息分割,研究了主要树木种群的结构特征及空间分布格局。结果表明:锐齿栎的重要值为0.589 6,为当地的绝对优势种群;6种聚集度指标计算结果表明,栎类种群主要呈均匀分布;不同胸径大小级的栎类种群空间分布格局呈现一定规律,即随着栎类种群平均胸径的增加,空间分布格局从聚集分布向随机分布状态发展,而最近邻体平均距离从0.75m增加到1.42m;0～1m和1～2m距离范围内的林木株数比例分别从45%和46%递减到42%和33%。随着恢复过程的向前发展,该地栎类种群聚集程度逐渐减小,林分趋于动态平衡。

Structure and Spatial Distribution Patterns of the Main Woody Plant Populations of Oak Natural Secondary Forests in Baotianman Nature Reserve,Henan Province

The structural characteristics and spatial distribution patterns of main woody plant populations of the recovering oak natural secondary forests in Baotianman National Nature Reserve,Henan Province were analyzed by locating individual tree plant,and by setting off coordinate information with GIS software(Mapgis7.0).The results showed that the importance values of Quercus aliena var.acuteserata was 0.589 6,indicating its dominant position among local plant populations.The results of the calculation of six clump intensity indices indicated that oak populations were an uniform distribution.Spatial distribution patterns of the oak populations with different size classes showed certain regularities: with the increase of the mean DHB,the spatial distribution patterns of oak population changed from gathered distribution to random distribution,and the average distances between every neighbor-individual increased from 0.75 m to 1.42 m,the percentage of the trees with the average distances were in 0 m to 1 m decreased from 45% to 42%,and the percentage of trees with an average distances of 1 m to 2 m decreased from 46% to 33%.Aggregation degree of oak populations in Baotianman National Nature Reserve decreased gradually,and forest stands tended to become equilibrium with recovery process developed forward.