Investigation on most effective environmental factors influencing Juniperus communis establishment (Case Study: Arasbaran Forest, Mardanaghomchay Water catchment area)

The aim of the study was to determine the ecological factors influencing natural establishment and distribution of the medicinal shrub Juniperus communis at Arasbaran Forests of Iran. In order to start floristic studies, 97 sample plots (each 400 m2 area) were allocated in the studied area, based on the Minimal Area Statistical Method. Plant cover at different stories were identified and recorded, using the Modified Braun-Blanquet Method. After removing the organic layer of soil surface at the plots center, soil sampling was made at 10-20 cm depth. Soil physical and chemical analysis consisted of: organic carbon, total nitrogen, available phosphorus, exchangeable potassium, CaCo3, texture, Humus layer depth and pH. Two ordination methods, including DCA and CCA were applied to determine relationships between the species characteristics and environmental variables. Results showed that there is significant positive correlation between the Juniper density and exchangeable potassium and altitude and significant negative correlation with pH and CaCo3. The species preference to loamy and well drained soils was considered as well.