Ecological Survey of the Presence and Absence of Ferula ovina (Boiss.) Boiss. and Ferula persica Willd. in North-Western Rangelands of Iran (Case Study: Zanjan Province

This study was conducted to investigate the effect of ecological factors on distribution, presence and absence of species Ferula ovina and F. persica in the semi-arid rangelands of Zanjan province, Iran in 2015. The locations of ten 4m2 plots with 15m spacing on three 150 m long transects were systematically randomized and determined in each key area within each habitat. The soil surface features including total canopy cover, canopy cover of target species, bare soil and stone and gravel on the soil surface were estimated. Three mixed soil samples from the locations at the beginning, middle, and end of each transect from depth of 0-30 cm were collected to determine soil properties. Physiographic and climate factors of each selected site were determined. Independent sample t-test and one-way analysis of variance were conducted to compare the related parameters and the discriminant analysis was also performed to determine the importance of environmental variables on the presence and absence of the target species. The results showed that in F. persica habitat, the percentage of total neutralizing value and silt was less than that in the absence area of the species. In contrast, in F. ovina habitat, the amount of these variables was significantly higher than that in the absence area of the specie. The results of discriminant analysis showed that temperature parameters, altitude, sand and gravel percent on the soil surface, electrical conductivity, total neutralizing value and rainfall in the first canonical function had the highest value and they were the first factors affecting species distribution and location differentiation. However, presence and absence of species in the target habitats are often dependent on some variables such as pH, soil silt percent, aspect, precipitation and minimum temperature.