Study On Quantitative Ecology Of Quercus Acutissima Communities In Zhongtiao Mountains, Shanxi

Quercus acutissima communities in Zhongtiao Mountains, Shanxi were studied by using quantitative ecology methods, including community classification and ordination, species diversity and plant functional groups, respectively. The purposes of this study were to analyze the communities' structure and function, to interpret the interrelations between communities and environment and to present some theoretical basis for the conservation of this species and communities and sustainable utilization.Based on the 45 plots dataset from the field, Quercus acutissima communities were investigated by TWINSPAN and DCA in order to analyze the structure of the communities. The results from TWINSPAN showed that the 45 plots were classified into 10 associations. The results of ordination of the plots from DCA were as follows:the first axes of DCA ordination indicated significant correlation with slop and aspect, which suggested humidity and illumination that were the key factors in community's assembly, and there was a significant relationship between axis 2 and elevation, indicating the function of temperature. The ordination of the dominant species showed the same relationships between axis and environmental factors.Based on the result of TWINSPAN classification, the species diversity of the 10 associations and the three layers of the communities were studied by using species richness indices (Patrick index), species diversity indices (Simpson index and Shannon-Wiener index) and evenness indices (Pielou index and Alatalo index), respectively. The results demonstrated that:(1) The change trend of Patrick richness index was similar to that of Shannon-Wiener diversity indices, which was determined by the complexity of the associations and the numbers of species, but was opposite to Simpson diversity index. Accordant result was achieved by using the three indices. (2) The results from Patrick richness index and Shannon-Wiener diversity index of the shrub layer were higher than that of the tree layer and herb layer. The contributions of the species at different layers to the species diversity of the communities were not equivalent, and the species diversity indices of the communities were dependent upon the shrub layer mainly. (3) The results from ANOVA for the indices showed that the differences among richness index, diversity indices and evenness indices were not significant among the associations, which were resulted from that the distribution of the communities was narrower and the habitat heterogeneous of communities was not significantly and the structure of the communities was stable.Interspecies relationship of the dominants of the three layers of Quercus acutissima communities was analyzed by Fisher's exact test and Spearman's rank correlation. Moreover, the plant functional groups (PFGs) of the dominants of each layer in the communities were explored by using median clustering with Sorensen coefficient as well as the results of interspecies relationships. Finally,9 dominants of the tree layer were classified into three PFGs,19 dominants of the shrub layer were divided into 5 PFGs and 13 dominants of the herb layer were partitioned into 4 PFGs. The distribution of each PFGs was characteristically and these PFGs could reflect vegetation-environment relationships well.