太岳山华北落叶松人工林林下植物变化及环境解释

通过对山西太岳山好地方华北落叶松人工林林下植物群落进行调查，并通过典范对应分析（CCA），探讨了林下物种分布与环境因子之间的关系。结果表明，在调查的21个样地中，油松林下共出现植物物种70种，隶属28个科,56个属；CCA排序结果揭示了研究区内林下植物的分布格局与环境梯度的关系。林龄、坡向、土壤全氮等因素对林下草本层物种分布格局有重要影响；林龄、土壤全氮、坡位等因素是影响林下灌木层物种分布格局差异的主要环境因子；影响林下草本层和灌木层物种分布格局的变量中，生境因子和生物因子分别共同解释了草本层和灌木层52%和55%，生境因子分别解释了25.9%和22.5%，均高于生物因子的解释能力，表明生境因子在决定华北落叶松人工林林下植物分布格局变异中起着举足轻重的作用。

Changes and Environmental Interpretation of Understory Plants of Larix principis-rupprechtii Plantation in Taiyue Mountain

To understand the relationship between the distribution of understory plants and environmental factors in Larix principis-rupprechtii plantation,an investigation on understory plants was conducted in 21 plots in Haodifang,Taiyue Mountain in Shanxi.The environmental factors controlling understory plant composition and diversity were quantitatively assessed by the method of canonical correspondence analysis (CCA).The results showed that:70 understory species were recorded in 21 plots belonging to 26 families and 55 genera.The results of CCA revealed the relationship between the distribution of understory plants and environmental gradients: stand age,slope,total nitrogen were important factors determining plant distribution in the herb layer,while stand age,total nitrogen and slop position were important in the shrub layer.Habitat and biotic factors together explained 52% of the variation in the distribution of herb layer,and 55% in the distribution of shrub layer.Pure habitat factors exhibited a stronger interpretation for understory species distribution,suggesting that habitat factors may play a significant role in the distribution variance of understory plants.