Facrors affecting establishment and distribution of four halophytic species in Eastern Azarbayjan- Marand Gherkhelar rangelands

Plant communities are not independent from edaphic, microclimatic and biotic factors. In saline area the soil properties are one of the important factors influencing distribution of vegetation. The aim of this research was to investigate the relationship between some halophytic species such as Halonemum strobilaceum, Salsola dendroides, Atriplex verrceferum and soil characteristics to determine the most important factors affecting their distribution and establishment. Vegetation sampling was done in each plant community on ten transects with 50 m length at 100 m intervals. Along each transect canopy cover of species was recorded, and density of species was measured using point-quadrate method. Also in each community, we described soil profiles with digging holes and then soil was sampled in depths of 0-20, 20-40, 40-60 cm for physical and chemical analyses such as soil texture, Ec, pH, Na, Mg+Ca, ESP and PSW. Multivariate regression was applied to analyze soil and vegetation data. Results showed that there is a significant correlation between species distribution (density and cover) and soil characteristics. The most important factors on distribution and establishment of species were Ec, Na, PSW. Overall, the vegetation response to soil factors for this saline area could be expanded to explain the growth and development patterns of these species in similar area.