Investigation on biodiversity and richness of plant species in relation to physiography and physico-chemical properties of soil in Kabirkoh protected area

In order to investigate the reaction of biodiversity and richness of plant species in relation to physiography and physico-chemical properties of soil, Arasht catchment (approximately 500 ha) from Kabirkoh protected area in Ilam province was selected. After determining transects in different aspects, 67 sample plots (20m×20m) in a grid of 150m×150m were established (northern aspect 24 plots, western aspect 20 plots and southern aspect 23 plots). The environmental factors and vegetation in each sample plot were recorded. Results from correlation analysis showed that the biodiversity of herbaceous species in southern aspect has a negative relation with clay and sand and has a positive relation with silt and lime. The biodiversity of herbaceous species in northern aspect has a positive relation with soil saturation percentage, organic matter and nitrogen and has a negative relation with altitude. The biodiversity of herbaceous speciesin western aspect has a negative relation with EC and altitude and has a positive relation with lime. Based on the results, it can be stated that for ecological evaluations in Zagros region, physico-chemical factors are more suitable for herbaceous species and physiographic factors and land form are more suitable for shrub and tree species