闽楠天然次生林林木综合竞争指数研究

以江西省吉安市闽楠天然次生林作为研究对象,通过八邻域平移法确定对象木,分别采用四邻体法、Voronoi图法选取竞争木,并基于Hegyi简单竞争指数重新构建含胸径、树高、冠幅及林木间距等因子的综合竞争指数,利用Pearson相关分析法和曲线拟合比较分析不同方法选取竞争木的简单竞争指数与综合竞争指数的优劣。结果表明:1)简单竞争指数和综合竞争指数与胸径、树高及冠幅之间均呈极显著负相关(P<0.01);2)综合竞争指数与胸径、树高及冠幅的相关性和拟合度均高于简单竞争指数;3)基于Voronoi图法构建的简单竞争指数和综合竞争指数与胸径、树高及冠幅的相关性和拟合度均高于基于四邻体法构建的简单竞争指数和综合竞争指数。研究结果可为闽楠天然次生林的合理经营与保护等措施的制订提供参考依据。

Comprehensive Competition Index of Natural Secondary Phoebe bournei Forest

Based on the typical sample investigation on the natural secondary forest,the eight neighbourhood translation method was used to determine the objective trees.The competitive trees were selected by the methods of four neighbourhoods and Voronoi map.Based on the Hegyi simple competition index,the comprehensive competition indexes of the factors such as DBH,tree height,crown width and tree spacing were reconstructed.A comparative analysis was made between the simple competitive index and comprehensive competitive index of different selection methods of the competitive trees.The main results and conclusions were as follows:1)There was a significant negative correlation between the simple competition index and comprehensive competition index with the DBH,tree height and crown width (P <0.01).2)The correlations and the fitting degrees between the comprehensive competition index with the DBH,tree height and crown width were all higher than that of simple competition index.3)The correlations and the fitting degrees between the simple competition index and comprehensive competition index based on the Voronoi map were all higher than the simple competition index and comprehensive competition index constructed by the four neighborhood method.