青冈栎次生林主要树种空间分布格局及其关联性研究

Spatial distribution patterns and associations of the main tree species in Cyclobalanopsis glauca secondary forest

青冈栎次生林作为亚热带地区次生林的典型代表之一,研究其林分内主要树种的空间分布格局及关联性,可以更好地开展次生林经营指导工作。通过对9块青冈栎次生林样地的调查,运用空间点格局分析方法对其林分内主要树种的空间分布格局及种间关联性进行研究。结果表明:1)以完全空间随机模型为零假设时,林分整体的空间分布格局在0~12m尺度上呈聚集分布,在12~25m尺度呈随机分布,大于25m尺度趋于均匀分布态势;以异质泊松模型为零假设时,林分整体的空间分布格局总体上呈随机分布;2)样地内青冈栎、杜鹃和拟赤杨在小尺度上呈聚集分布,随尺度增加呈随机分布或均匀分布;甜槠、杉木和檵木基本在所有尺度呈随机分布。3)样地内建群种青冈栎与杉木在所有尺度呈负相关,与其它主要树种在小尺度呈负相关,随着尺度增加变为不相关;所有伴生树种的种间关联性在0~2m为负相关,在其它尺度上不相关为主。青冈栎次生林的空间分布格局受生境异质性的影响,且空间分布格局和主要树种间的关联性随空间尺度的不同而变化。

As one of the typical secondary forests in subtropical regions, the spatial pattern and the correlation between the main tree species of the secondary forest of Cyclobalanopsis glauca can be studied to better guide the secondary forest management.Based on 9 sample plots of Cyclobalanopsis glauca secondary forest, the spatial distribution pattern and the correlation among the main tree species were studied by means of spatial point pattern analysis.The results showed that: 1) when the complete spatial random model was taken as the null hypothesis, the overall spatial distribution pattern of the stand presented an aggregation distribution on the scale of 0-12 m, and a random distribution on the scale of 12-25 m, and tended to be uniformly distributed on the scale larger than 25 m. When the heterogeneous poissonprocess modek was taken as the null hypothesis, the spatial distribution pattern of the sample plot was random on most scales. 2) On small scales,the distribution among Cyclobalanopsis glauca, Rhododendron simsii, and Alniphyllum fortunei were aggregation distribution, withing the increase of scale, the distribution tendedtorandom distribution or uniform distribution. On all scales, the distribution among Castanopsis eyrei, Cunninghamia lanceolate and Loropetalum chinensis wererandom distribution. 3) Cyclobalanopsis glauca and Cunninghamia lanceolate were negatively correlated on all scales ,and the relationship between Cyclobalanopsis glauca and other main tree species was negative correlation on small scale ,and became irrelevant with the increase of scale. The interspecific correlations of all associated tree species were negative at 0-2 m, and became irrelevant on other scales. The spatial distribution pattern of the secondary forest was affected by the habitat heterogeneity, and the spatial distribution pattern and the correlation among the main tree species varied with the spatial scale.