Investigation on changes in vegetation by effects of environmental factors using conservatism species

The vegetation ordination and classification based on conservatism species can be better able to analyze the ecological relationships between vegetation and environmental factors. This study aimed to investigate changes in herb layer vegetation of Quercus brantii, Q infectoria, and Pyrus glabra forest types based on conservatism species, at different environmental factors. Tree and herb layer was surveyed using 24 main plots (500m2) and 3 sub-plots (4m2) randomly distributed in each main plots, respectively. Crown canopy, physiographic features, and some edaphic factors were measured in each main plot. Species richness and species frequency were recorded in sub-plots as an abundance index. The relation between environmental factors and herb layer dynamic were investigated by ordination (CCA, PCA & DCA) and classification (TWINSPAN) methods after determining conservatism species. Based on the results of ordination and classification, herbaceous layer in Q. brantii type was significantly different in species composition and physiographic and edaphic factors from Q. infectoria and P. glabra types. Herbaceous layer in Q. brantii type showed a positive correlation with high levels of nutrients and the effective main components were OC, N, K, sand, altitude, and saturated humidity in top soil. The Q. infectoria and P. glabra types were observed in calcareous and heavy soils low elevation with nutrients deficiency. The herbaceous layer and soil in Q. brantii type seems to be more evolved due to climax tree layer.