空间竞争指数在华北土石山区天然次生林的应用

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为了揭示森林群落内林木竞争关系,对比分析不同空间竞争指数的特点与关系,采用大小比数和开敞度对木兰围场国有林场管理局域内天然次生林林木竞争强度进行定量分析。研究结果显示:研究区天然次生林林分内各树种大小分化较为明显,平均大小比数为0.476;林分内不同种群和林木个体生长空间分配并不均匀,差异较大,全林分开敞度为0.282,处于不足状态;树种大小比数与开敞度呈负相关关系,但其相关性显著程度存在差异。大小比数与开敞度计算结果存在差异,且这一差异主要受控于两种指数对参照木与相邻木距离的不同处理方法。大小比数全面考虑了参照木与相邻木之间的大小关系,但忽略了参照木与相邻木之间的干扰程度随二者距离增大而降低的特性;开敞度虽然考虑了参照木与相邻木之间的距离,却又将参照木与相邻木抽象为没有大小的点与线,忽略了二者之间的大小关系。 In order to reveal the competitive relationship between forest trees in forest communities and compare and analyze the characteristics and relationships of different spatial competition indexes, the competition intensity of natural secondary forest in the management area of ​​Mulanweichang state-owned forest farms was quantitatively analyzed by the size ratio and openness. The results showed that the size of each tree species in the natural secondary forest was more obvious in the study area, the average size ratio was 0.476. The spatial distribution of the growth of different populations and individuals in the forest was not uniform, the difference was large, 0.282, in a deficient state. There was a negative correlation between species size and openness, but there was a significant difference in their correlation. There is a difference between the size ratio and the openness calculation result, and this difference is mainly controlled by the different treatment methods of the two indices on the reference wood distance to the adjacent wood. The size ratio fully considers the relationship between the size of the reference wood and the adjacent wood, but ignores the reference wood and the adjacent wood interference between the two increases as the distance decreases with the characteristics of; Although the open space to consider the reference The distance between wood and adjacent wood, however, will refer to the point and line between the wood and the adjacent wood abstracted as no size, ignoring the size relationship between the two.
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