Study of effective ecological factors on distribution of vegetation types (Case study: Southern margin of Haj Aligholi Kavir, Damghan)

Abstract The objective of current research is to investigate distribution patterns of vegetation types and its relation with environmental factors in southern margin of Haj Aligholi Kavir of Damghan. Three vegetation types including Halecnemum strobilaceum, Sedlitzia rosmarinus and Artemisia sieberi were studied in marginal arid regions and uplands of the study area. Firstly, geographic location of vegetation types was determined using GPS. Then the boundary of the region was delineated on the topographic map in scale 1:50000. Elevation, slope and aspect of vegetation types were determined as well. Ten plots were established in the field based on randomized – systematic approach. The area of each plot was determined according to the kind of plant species and distribution of plants. Floristic list, canopy cover and average percent of species canopy cover were determined in each plot. Finally, five soil samples were taken in each vegetation type. The characteristics of soil samples including texture, EC, pH, %CaCO3, %CaSO4, %OM, SAR and ESP were measured too. ANOVA and Duncan's test were used to analyze the collected data. The result of analysis of variance showed that F test of all studied characteristics except %CaCO3, %CaSO4, %OM and elevation is significant in %1. The results of Duncan's test showed that soil texture, EC, SAR, ESP and pH of Halecnemum strobilaceum type is significantly different from two other types. Also, SAR, ESP and slope in habitat of Artemisia sieberi and Sedlitzia rosmarinus types were significantly different