The evaluation of herb Layer biodiversity in relation to physiographical factors in south of zagros forest ecosystem (case study: Dalab protected area)

Zagros ecosystem is considered as one of the most important biological sites in the country. This ecosystem is very important in terms of size (40 percentage of total forest), flora and fauna species, genetic reserves, under story vegetation and such like. Considering the large number of traps and ranchers in this region, having the essential details and information about the plant species diversity is highly important in order to revive the vegetation in the area. For evaluation of plant species diversity and richness of herbaceous species related to physiographic factors, part of DALAB area in north of ILAM approximately 1000 ha in central Zagros forest was selected. For this study 320 plots (2×2 meter) on different aspect transect were selected and in each plots all of herbaceous and surface covers evaluated. The results of this study showed elevation had significant difference on plant species diversity and richness, low altitudes class (1600>) has the most, while the high altitudes class (1800<) has the least diversity. Results showed that aspect had a significant impact on plant species diversity and richness of herbaceous species and Plant species diversity and richness higher in south aspect than other aspect though it did not have any significant difference with regard to evenness. The results also showed that the slope had significant effect on plant species diversity and richness and heist plant species diversity and richness in <30 slope class.