Environmental factors-ecological species group relationships in the Surash lowland-mountain forests in northern Iran
13 September 2016
Bazdidvahdati, Fatemeh; Saeidi Mehrvarz, Shahryar; C Dey, Daniel; Naqinezhad, AlirezaIdentification of the primary factors that influence the ecological distribution of species groups is important to managers of lowland-mountain forests in northern Iran. The aim of this research was to identify main ecological species groups, describe the site conditions associated with these species groups and the relationships between environmental factors and the distribution of ecological species groups using multivariate analysis of detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA). For this purpose, 50 relevés (400-m2 each) were sampled using the Braun-Blanquet method. Vegetation was classified into three ecological species groups using a modified Two-Way Indicator Species Analysis (TWINSPAN). In each relevé, environmental factors (topographic and soil variables) were measured and these have been assessed using one-way ANOVA and Pearson r statistics. Also, species diversity indices were determined for the identified ecological species groups. Results showed that the environmental factors including elevation, slope, slope aspect, soil texture, pH and organic matter were among the most important factors explaining the distribution of the three ecological species groups in the study area. Ecological species groups at higher elevations and higher slopes had lower diversity. The results of this study provide a valuable ecological basis for forest management and developing strategies for forest conservation in the study area.