重庆四面山森林植物群落数量分类和排序

采用双向指示种分析法(TWINSPAN)和除趋势典范对应分析法(DCCA)对重庆四面山森林植物群落进行数量分类和排序。TWINSPAN等级分类将四面山50个调查样地划分为14类,代表14个群系,分类的结果比较全面地概括了四面山的森林植被类型,属亚热带性质的次生植被类型。DCCA二维排序的结果与TWINSPAN分类结果较为一致,TWINSPAN分类所得到的14个群系在DCCA二维排序图上均有其相应的分布范围,但不同的森林植物群落间没有显著的分界界线。由海拔决定的土壤水分和温度的综合梯度是决定四面山植物群落分布格局的主要环境因素,坡度和坡位对植物群落的分布也有一定的影响。另外,大面积人工营造杉木林也对植物群落分布起到较大的影响作用。

Quantitative Classification and Ordination of Simian Mountains,Chongqing

Based on the field survey of plant quadrates,a quantitative analysis of the communities on Simian Mountains,Chongqing was performed with TWINSPAN(Two way indicator species analysis) and DCCA(Detrended canonical correspondence analysis) methods.Fifty quadrates collected from Simian Mountains were classified into fourteen types,representing fourteen formations by TWINSPAN.The result of classification sum up the forest vegetation types of Simian Mountains comprehensively.Fourteen formations are all subtropical nature of the secondary vegetation types.The gathered groups of plant quadrates in the space of DCCA ordination are consistent with the result of TWINSPAN,fourteen formations resulted from TWINSPAN all have its corresponding distribution in the two-dimensional sorted map DCCA,but there is no obvious boundaries between different plant communities.This reveals a relationship between plant formations and environmental gradients.The integrated gradient of soil moisture and temperature determined by the elevation is the main environmental factors which determine the distribution pattern of plant communities in Simian Mountains,and slope degree and slope position impacts the distribution in some extent,too.In addition,human disturbance also plays an important role in the distribution of plant communities.