application of classification methods and geographical information system (gis) techniques to identify vegetation structures and vegetation map(case study: andevar rangelands,amol)

in this study, we applied classification methods and geographic information system(gis) techniques to identify vegetation structures in andevar rangelands. homogenous work unit maps were produced by overlaying the layers of slope, aspect and digital elevation. totally 95 homogenous units were determined in which the field studies were carried out. vegetation sampling was done in 69 transects and 345 1x1 m2 plots. in the next step vegetation cover information was analyzed using classification methods and finally 9 vegetation groups were identified. then vegetation map of the area was produced combining geographic information system and cluster analysis. the resulted map showed that dactylis_medicagotype mostly is distributed in 1600 to 1900m elevation range. in elevation range of 2200 to 2500m in northern slopes of southern part of the area juniperus _ astragalusisdominant type. in southern slopes of northern part of the area dactylis_medicago type was replaced by artemisia_astragalus and ephedra_astragalustypes. in fact, the increasing of altitude caused the change of woody and spiny cushions species to herbaceous species.