地形因子对亚热带针阔混交林树种多样性的影响

【目的】揭示地形因子对亚热带针阔混交林树种多样性的影响,为森林可持续经营管理奠定技术基础。【方法】基于浙江省2009年国家森林资源清查(NFI)数据,选择树种组成多样性指数(I_SCD)、Margalef指数、Simpson指数、Shannon-Wiener指数、Alatalo均匀度指数、Pielou均匀度指数为树种多样性指标,通过分析各多样性指数在海拔、坡度、坡向、坡位等4个地形因子不同梯度间的变化,并对其进行差异性检验,解译地形因子对树种多样性的影响情况。【结果】I_SCD、Simpson指数、Shannon-Wiener指数以及Pielou均匀度指数在海拔梯度间存在显著差异,I_SCD、Simpson指数以及Shannon-Wiener指数在坡度梯度间存在显著差异,树种多样性指数值在不同坡向间没有显著差异性,Margalef指数与Alatalo均匀度指数在不同坡位间存在显著差异。【结论】亚热带针阔混交林多样性水平较高。海拔和坡度对树种多样性有明显的综合影响效应,对树种数量和分布均匀性影响不大;坡向对针阔混交林的树种数量、分布均匀性及其综合效应均没有明显的影响;坡位影响树种分布的数量、分布均匀度,但对树种多样性的综合效应影响不明显。

Effects of topographic factors on tree species diversity in subtropical coniferous and broad-leaved mixed forests

【Objective】 The coniferous and broad-leaved mixed forest is the main forest type in subtropical areas. Revealing the influence of topographic factors on tree species diversity is the technical basis of the sustainable forest management. 【Method】 Based on data from national forest inventory (NFI) sample plots in Zhejiang Province, China, the tree species composition diversity index (I_SCD), the Margalef index, Simpson index, Shannon-Wiener index, Alatalo index and Pielou index were used as tree species diversity indicators. The influence of topographic factors on tree species diversity was elucidated by analyzing variation patterns for each diversity index across different gradients of four topographic factors, namely elevation, slope, slope direction and slope position. 【Result】 The I_SCD, Simpson index, Shannon-Wiener index and Pielou index were significantly different between the elevation gradients. The I_SCD, Simpson index and Shannon-Wiener index were significantly different between the slope gradients. The tree species diversity index values were not significantly different between slope orientations, and the Margalef index and Alatalo index significantly differed between slopes. 【Conclusion】 The subtropical coniferous and broad-leaved mixed forests had a high diversity level. The elevation and slope had significant combined effects on tree species diversity, and had little effect on the number of tree species and distribution uniformity. The slope direction had no significant effect on the number of tree species, distribution uniformity and their combined ifluences of the coniferous and broad-leaved mixed forests. The slope position influenced the number and distribution uniformity of tree species distribution, and had no obvious effect on tree species diversity.