【摘要】 林分结构特征对灌木层物种多样性有重要影响,对其之间关系进行研究,可为提高生态系统功能稳定性、进行合理的林分经营管理提供理论依据。以马尾松林为研究对象,采用多元逐步回归、因子分析和典型相关分析等方法分上林层、中林层和下林层研究林分结构对灌木层多样性的影响。结果表明:(1)Pearson相关分析结果表明,上林层是影响灌木层物种多样性的主要层次,而林分总体结构特征与灌木层物种多样性无显著性关系;(2)用13个林分结构参数和灌木层物种多样性各参数进行多元逐步回归,拟合方程都通过显著性检验,R2为0.246-0.630,且仅剔除了树高和大小比数2个变量而保留了其它11个林分结构变量,说明林分结构的综合作用对灌木层物种多样性有较大影响;(3)林分结构可分为3类,分别为林分竞争状况因子、水平结构及冠幅因子和垂直结构及生长因子;(4)上林层林分结构总体上与灌木层物种多样性之间存在着较强的相关性,典型相关系数为0.822(P=0.014),其中垂直结构及生长因子为主要影响因子,权重为0.962。在马尾松林中,上林层林分结构中的垂直结构与生长因子和灌木层物种多样性表现为正相关关系,在经营管理中,可通过调控上林层林木的胸径、冠长及冠层垂直结构等以达到提高林分灌木层物种多样性的目的。更多还原

【Abstract】 Forest stand structure had great influence on the species diversity of shrub layer.Studying the relationship between stand structure characteristics and shrub layer species diversity could improve the stability of ecosystem function and provide theory basis for scientific forest management.We took Pinus massoniana forest as research object,then employed multiple stepwise regression,factor analysis,and canonical correlation analysis to study the influence of stand structure on the diversity of shrub layer by dividing upper layer,middle layer and lower layer.The results showed that:(1)The results of Pearson’s simple correlation analysis showed that the upper layer was the main layer that affected the species diversity of shrubs,while the correlation between overall stand structural characteristics and the species diversity of shrubs was not significant.(2)13 stand structure parameters and shrub layer species diversity parameters were used for multiple stepwise regression,and all the regression equations had passed the significance test,and R2 was 0.246-0.630.Only 2 variables of the tree height and neighborhood comparison were removed from the regression equations,while the rest 11 variables were retained in the equations,which indicated that the comprehensive effects of stand structure characteristics had great influence on the shrub species diversity.(3)The forest structure characteristics were divided into 3 types,which were forest competition status factor,horizontal structure and canopy width factor and vertical structure and growth factor.And(4)the correlation between forest stand structure of upper layer and the diversity of shrub layer was strong,and the canonical correlation coefficient was 0.822(P=0.014),of which the vertical structure and growth factor was dominating factor with whose heavy weight was 0.962.In Pinus massoniana forest forests,the vertical structure and growth factor of the upper layer is positively correlated with the the species diversity of the shrub layer.In the management,the aim of improving the species diversity of shrub layer can be achieved by adjusting the DBH,crown length and canopy vertical structure of the upper layer.更多还原