floristic structure and vegetation composition of boralan mountainous rangelands in north-western azerbaijan, iran

recognition of habitats and conditions of species presences in differentsituations can be effective in proper utilization of vegetation. little is known about thevegetation composition of boralan mountain region located in north west of iran in theborder of turkey and azerbaijan with the altitude range of 800-2000m. the aim of thisstudy therefore was to investigate the floristic composition quantitatively and analyze thevegetation response to altitudinal gradient conditions of mountain. firstly, plants werecollected by floristic field survey and identified using the floras. to investigate therelationship between the gradients of elevation and vegetation, two transects of 100m wereestablished at every 100m of elevation belts and the percentages of canopy cover anddensity of species were totally recorded in 20 plot samples using a random plot design.plant community zones were characterized on the basis of species’ cover dominances usingcluster analyses. according to this study, the area includes 108 species that were classifiedinto 26 families. totally, poeaseae and asteraceae with 40 percent cover dominance weremore frequent than other families. based on species similarity of elevation classes, thecluster analysis led to four vegetation type groups. the grass group and the shrub groupoccurred on high altitudes at 1900 m and lowland sites at 800-1300 m, respectively. theresults also showed that elevation variations had considerable effects on diversity andrichness indices of vegetation groups with the highest number of species at high altitudinalbelt. it seems that precipitation improvement and low grazing intensities has mainly causedthese changes.