Introduction of Khybus plant communities and their relation to physiographical factors and plant biodiversity indices

The main objective of this study was identifying Box trees (Buxus hyrcana Pojark.) communities and survey of their relationships to some physiographic attributes and plant biodiversity indices in Khybus Protected Area which is one of the best and most virgin Habitats of Box trees in Hyrcanian forest. The field data were obtained in 65 sample releves in a systematic- selective design (200 × 400 meter) by consideration Braun- Blanquet indicator stands concept. Physiographic attributes and plant biodiversity indices were also recorded in each releve. Vegetation data were analyzed using TWINSPAN. The data were classified into six plant communities. The results of ANOVA showed that these plant communities reflected underlying differences in altitude, northness, slope, richness and pielou evenness. Then Plant communities were ordinated using DCA from basis of diagnostic plant species percentage cover and the correspondence scores of the two first axes, which have explained the 25.5% of total variation changes in floristic data. The correlation between plant communities with environmental factors and plant biodiversity indices were determined by Pearson correlation coefficient. The DCA ordination showed that each plant community has its own range and are separately distributed. Also the first DCA axis was associated with the altitude, northness, richness, Shannon- wiener diversity and Pielou evenness among the communities, while the second one showed significant correlation with the slope gradient among the communities.