戴云山黄山松群落与环境的关联

基于戴云山黄山松群落类型31个样地(20 m×20 m)野外调查,筛选4个地形因子和11个土壤环境因子,采用除趋势典范对应分析法(DCCA)探讨黄山松群落分布格局与环境之间的关联,定量分析环境因子间相互关系及其对黄山松群落格局的影响。结果表明:(1)DCCA第一排序轴主要反映黄山松群落的海拔变化,第二轴主要反映坡向变化,即沿第二轴从上到下,坡向越朝向阳坡,黄山松群落分布越明显。(2)DCCA表明第一轴与海拔的相关系数达0.5570,即海拔是黄山松群落分布起着决定性作用的环境因子,呈现海拔越高,黄山松优势种群越显著,在海拔1400-1600 m表现突出。(3)黄山松群落主要物种在DCCA排序图的相对位置,反映坡向、坡位、有机质、人为干扰因素是影响黄山松群落分布的重要因素。(4)DCCA排序图中黄山松群落种类排序轴与环境排序轴的相关系数高于DCA,且消除CCA的 "弓形效应",更能凸显海拔、有机质等环境因子对黄山松群落的影响,即黄山松群落与环境因子之间关联以DCCA排序方法为最佳。

Association between environment and community of Pinus taiwanensis in Daiyun Mountain

Daiyun Mountain is one of two great mountains in Fujian Provice, located at the boundary between mid-subtropic and south subtropic. Daiyun Mountain National Nature Reserve established in the sample area is one of the nature reserves with the highest biodiversity in unit area in China. Daiyun Mountain has 6400 hm² protogenesis Pinus taiwanensis community which is the most south tip,the biggest area and the best preserved natural P.taiwanensis community area in China mainland. Daiyun Mountain also is the largest germplasm genetic base of P.taiwanensis in China, which is important to carry out research on the succession of mid-subtropical vegetation. Based on the field investigation of thirty-one sample plots (20 m × 20 m) of P.taiwanensis community in Daiyun Mountain, the environmental factors (11 soil factors and 4 terrain factors) were selected. The relevance between distribution pattern and environment was discussed by Detrended Canonical Correspondence Analysis (DCCA). The relationship among environmental factors was quantitatively analyzed. The results showed that:(1) The DCCA first sorting axis mainly reflected spatial variability of elevation, the second axis mainly reflected the change of slope, slope tends to the sunny side with the second axis from top to bottom, meanwhile P. taiwanensis communities distribute obviously. (2)The DCCA sorting indicated coefficient between the first axis and the elevation reaches 0.5570, that is, elevation is decisive function factor for P.taiwanensis communities,presenting the higher elevation is, the more remarkable P.taiwanensis population is especially in elevation 1400-1600 m.(3) Different species of P.taiwanensis communities has different environmental factors in the DCCA sorting chart, simultaneously the slope, the slope position, the organic matter, the human factor also are the important factors of P.taiwanensis communities. (4)The sorting results obtained from DCA (Detrended Correspondence Analysis), CCA(Canonical Correspondence Analysis)and DCCA have some differences.DCA mainly reflects P.taiwanensis community difference, while CCA exists "Arch Effect". With a combination of DCA and CCA, DCCA showed a higher correlation coefficient between the P.taiwanensis community and environmental sorting axis as compared with DCA, indicating that DCCA can give a better explanation on the relationship between P.taiwanensis community and environmental factors such as elevation and organic matter. Moreover, there is not "Arch Effect" in DCCA. Therefore, DCCA may be the best choice in study on the relationship between P.taiwanensis community and environmental factors.