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Volume 9, Issue 3 (10-2010)
Abstract
This study was carried out in Kalat highlands of Gonabad, Eastern Iran, located in geographical position of 34º 6´ to 34º 16´ N and 58º 25´ to 58º 35´ E with the altitude of 1100 to 2830 m.a.s.l. The mean annual precipitation and temperature are 143.2mm and 17.2ºC, respectively. Species richness, evenness and species diversity, diversity and related models, diversity based on the rank/abundance plots as well as methods of diversity ordering were considered in three elevation zones including low, intermediate and high altitudes and in the four slope aspects. Species richness indices in the intermediate zone were more than those in the low and high altitudes. The intermediate zone showed the highest species diversity as well as the highest evenness among the zones. North aspect showed the highest species richness and lowest species diversity and evenness. The highest diversity and evenness were observed in the south and south and west aspects, respectively. The low altitude zone followed lognormal distribution however intermediate and high altitude zones do not fit any of the models. Species abundance patterns of the north and west aspects followed both lognormal and logarithmic models with a shift from being lognormal to logarithmic model. The intermediate altitude zone and the south aspect had more flattened rank/abundance plot therefore they have been more diverse than the others. The same was observed by using diversity profiles.