太岳山油松人工林林下植被生物量影响因子分析

Analysis on infl uence factors of undergrowth vegetation biomass in Pinus tabulaeformis plantation in Mount Taiyue

摘 要：通过调查和分析油松林下植被物种组成特征及生物量，运用灰色关联分析、主成分分析和系统聚类方法，研究了各影响因子不同梯度水平下林下生物量所呈现的分布规律。结果显示：油松人工林林下草本生物量大于灌木生物量，草本层植被生物量为 0.339 8 ～ 1.322 9 t·hm-2，灌木层生物量为 0.018 1 ～ 0.289 2 t·hm-2；加权后的关联度与原始关联度排序大致相同，关联性最为密切的因子同为林分均高、林分胸径及林龄，但加权后各单因子关联度数值间差异性增加；以样地作为各单因子聚合的系统进行聚类，样地划分为 4 个类型，分类结果可反映林下生物量的分布格局。

The species composition characteristic and biomass of undergrowth vegetation of Pinus tabulaeformis plantations in Mount Taiyue in Qinyuan county in Shanxi province were investigated and analyzed, and by using grey relational analysis,principal component analysis and hierarchical clustering method,the distribution rules of undergrowth vegetation in different gradient levels of main infl uence factors were studied. The results indicate that the biomass was 0.339 8 ~ 1.322 9 t·hm-2 in herb layer and 0.018 1 ~ 0.289 2 t·hm-2 in shrub layer; the sequence of weighting relational degree was roughly the same as that of the original,but the numerical difference of infl uence factors increased in weighting degrees; the stand height, stand mean DBH and stand age were closely related to biomass of undergrowth vegetation. The samples were clustered as system and the clustering results could accurately refl ect the distribution pattern of undergrowth vegetation biomass.