长白山北坡草本植物分布与环境关系的典范对应分析

在长白山北坡海拔700～2600m的坡面上，海拔每上升100m设立一块样地，共计20个样地，计测样地中草本层植物的生态重要值和包括气候、土壤、林冠郁闭度等在内的13个环境因子，对获得的数据进行典范对应分析，作出了种类、样地分布与环境因子关系的二维排序图，排序图直观地反映了主要草本植物分布与环境因子间的关系。排序图中环境因子与前两个排序轴的相关系数大小表明，海拔高度作为诸多环境因子的综合反映，是影响长白山北坡草本植物分布的主导因素，除此之外，其它环境因子如林冠郁闭度、土壤有机质及有效N、P、K等因素，也对草本植物的分布有较大的影响。高山冻原与2000m以下森林群落内的草本植物明显不同，反映出二种不同类型植被间草本植物组成格局间质的差异。

Canonical correspondence analysis on relationship of herbs with their environments on northern slope of Changbai Mountain

The study on the relationship between herb plants a nd their environments is very important for understanding herb diversity pattern s. The study area is located on the northern slope of Changbai Mountain where th ere is not only a high diversity in vegetation types and species, but also high variation of diversity pattern along the altitude gradient. There exists obvious environmental gradient and species compositions are varied obviously along alti tude gradient. It is a perfect transect for the research of biodiversity and gra dient patterns. From altitude 700m to 2600m on northern slope of Changbai Mounta in, 20 plots were sampled with an interval of 100 m along the altitude gradient. In each plot, the ecological important values of herbs, together with 13 enviro nmental variables including weather, soil factors,canopy density, etc. were obt ained. The data were analyzed with the method of Canonical Correspondence Analys is (CCA). The species,plots environment biplots were drawn based on the resu lt of CCA, and the relationships between the ecological distribution of the species and communities with the 13 environmental factors were clearly revealed on thes e biplots. 20 plots could be divided into 2 groups, which corresponded the tundr a and forest vegetation. Furthermore, forests could be divided into 3 groups, wh ich corresponded Broad leaved Korean pine forest, Dark coniferous forest and Betula ermanii forest. Same as the plots, herb species also could be divided i nto 2 groups, which were tundra species and forest species. There were a high co possession of herb species among the different forest types along the altitude gradient. On the contrary, there were a low co possession of herb species betw een the tundra and forests. The herb communities on the tundra were distinctivel y different from those on the forests under altitude 2000m. As a comprehensive e xpress of many ecological factors such as precipitation, temperature, soil facto rs, etc, altitude was a key environmental variable for herb species patterns. Be sides altitude, canopy density was one of the important factors for influencing the ecological distribution of the herb species in forests according to the corr elation coefficients of the environmental variables with the first two axes.