关帝山云杉次生林树木径向生长的空间关联及其影响因子

以关帝山4 hm²云杉次生林样地为研究对象，按照CTFS(Center for Tropical Forest Science)技术规范对样地树木进行连续定位监测。利用2010至2015年间样地主要树种生长量观测数据，结合地形、土壤等环境因子调查及采样测定数据，分析了树木种群径向生长的空间关联性及其随生境的变化，并探讨了树木种群径向生长的影响因素。结果表明，青杄、华北落叶松、红桦、白桦和辽东栎为云杉次生林主要树种，在样地4个生境型(山脊生境、低海拔缓坡生境、高海拔缓坡生境、低洼地陡坡生境)中均有分布且呈现不同的径级结构。标记相关函数分析显示，同一生境型中，5树种径向生长的空间关联性各异；对于同一树种，径向生长的空间自相关性不仅具有尺度依赖性，同时生境型的不同导致树木径向生长的空间关联性发生变化。线性混合效应模型分析显示，初始胸径对树木径向生长的显著正效应在样地各类生境型的所有种群中普遍存在；生物因子对树木径向生长的显著影响只在特定生境型的青杄种群中被检测到，表明树木径向生长受同种邻体影响，但其影响显著性因树种而异；环境因子中，海拔和凹凸度对树木径向生长呈显著负效应...

Spatial autocorrelation patterns and influencing factors of tree radial growth in the secondary Picea forest in Guandi Mountains, northern China

This study took the 4 hm² sample plot as the research object in Guandi Mountains, Shanxi Province, and trees were continuously positioned and monitored according to Center for Tropical Forest Science (CTFS) technical specifications. Based on the observation data of tree radial growth in the sample plot from 2010 to 2015, combined with the survey and sampling measurement data of environmental factors such as terrain variables and soil variables, we analyzed the spatial autocorrelation patterns of radial growth of tree populations and their variation with different habitat types, and explored the influencing factors of the radial growth of the tree populations. The results showed that Picea wilsonii, Larix principis-rupprechtii, Betula albosinensis, Betula platyphylla, and Quercus wutaishanica were main tree species in the secondary Picea forest, which were distributed in four habitat types (ridge habitat, low-altitude gentle slope habitat, high-altitude gentle slope habitat, and low-lying steep slope habitat) with different diameter structures. The mark correlation function (MCF) analysis showed that the spatial autocorrelation characteristics of radial growth of the five tree species were different in the same habitat type. For the same tree species, the spatial autocorrelation characteristics of radial growth was not only scale-dependent, but also changed with different habitat types. The linear mixed-effects model (LMM) analysis showed that the significantly positive effect of initial size, i.e diameter at breast height (DBH), on tree radial growth was prevalent in all populations of all habitat types in the plot. The significant effects of biotic factors on radial growth of trees were detected only in the population of Picea wilsonii in specific habitat types, indicating that the radial growth of trees was affected by conspecific neighbors, but the significance of its influence varied with tree species. The environmental factors had significant effects on radial growth of specific tree species in specific habitat types. Among the environmental factors, altitude and convexity had significantly negative effects on radial growth, and slope, soil principal coordinate analysis (PCA) axis 1 (acidic pH and higher content available manganese, available nickel, available iron, available copper), and soil PCA axis 2 (higher content of total salt, available nitrogen, available potassium, organic matter) had significantly positive effects on radial growth. The radial growth of trees and the formation of spatial autocorrelation patterns of trees in secondary Picea forest were jointly driven by the initial DBH, neighbors, and habitat factors.