Effects of Physiographic Factors on Density, Canopy Cover and Production Medicinal Species Ferula Orientalis (Case Study: Shohada Valley of Urmia)

Plants are the major component of natural ecosystems including the rangelands which extend all they largely controlled by environmental factors and ecological, climate, soil, topography and biological properties are effective on their presence and traits. This study was performed in the Shohada valley of Urmia in order to evaluate the effect of physiographic factors on density, canopy cover and production of Ferula Orientalis.

According to the current situation in the region, three height floors, three direction floors and seven slope floors were selected. Also, 8 sites were identified in the study area. In each site, 3 transects with a length of 100 meters were systematically-randomly plotted along each transect and 5 parameters were recorded. Analysis of variance was used to investigate the differences between the studied parameters and physiographic factors and Duncan's multiple range tests was used to compare the mean of the traits.

Most density of studied species was observed in the 1700-2300 meters height class with 7,500 individuals per hectare. Also, the highest level of the species extends belong to slope of more than 70 percent with an area of 97 ha. The highest level of the aspect is related to East with 3/148 ha.

According to the results of this study, it can be said that the elevation, slope and aspect significantly have been effective on density, canopy cover and production of Ferula Orientalis. Generally the results showed that the highest density, canopy cover and production belonged to 1700-2300 meters altitude and on the slope above 70% and in the east aspect.