Study the effects of elevation, slope and aspect on life form forage production in Sabalan rangelands in Ardabil province

The purpose of this study was to investigate the relationship between rangeland plants production based on total production and life forms of grasses, forbs, and shrubs with topographic factors (altitude, slope, and aspects) in Sabalan rangelands, Ardabil province. To determine the annual total production, the amount of production was estimated using harvesting method in one square meter plots (totally of 216 plots) under the altitude range of 1200 to 2900 meters a.s.l. Using topographic maps, the digital elevation model was derived and classified maps of elevation, slope, and aspect were derived. Then, in each plot, information such as elevation, slope, and aspect was extracted. The correlation between life forms and topographic factors was analyzed using multivariate regression method. The results showed that there was a significant relationship between the production of life forms such as grasses (P0.05). The production of grasses, forbs and total production had direct relationship with slope; however, the production of shrubs decreased with the increase of slope. The production of grasses increased with altitude, and in the east-faced slopes, it was estimated more than the other aspects. The production of forbs decreased with the increase of altitude and was higher in the east aspect in comparison with the other aspects. The production of shrubs and total production in the middle altitude and in north –faced slopes were more than the other classes and aspects according to the suitable ecological condition and low degradation. Although it is obvious that elevation, slope, and aspect can change and affect the production, this effect is unknown, especially in the connection with life forms and the process of change. Overall, it can be concluded that these results could be used in the management of these rangelands, particularly in the improvement and rehabilitation practices.