Determination and Comparison of Preference Value for Five Halophyte Species in the Marginal Rangeland of Salt Lake in Aran and Bidgol Region, Kshan, Iran

Since the halophytes species have an important role in such ecosystem balance and they have been grazed by livestock as supplementary forage, the awareness of livestock's desire to grazing and their preference values of these species is of high priority. Regardless of the importance of halophyte species in the livestock feeding in Iran, there is less published research on the livestock grazing from these species. In present study, the preference value of the five halophyte species (Seidlitzia rosmarinus, Salsola crassa, Aeluropus littoralis, Suada fruticosa and Anabasis setifera) was determined using preference index and timing methods in the marginal rangelands of Aran and Bidgol salt lake, Kashan, Iran in 2013-2016 during the grazing season. The preference values of these halophytes spices were assessed using Whittaker and Niering method. In the timing method, the animal grazing for 20 minutes was filmed for 1 to 2 hours after the flock arrival to the rangeland, and the grazing time of each species was recorded. According to the results of the analysis of variance, the species effect was significant for both grazing time and preference index (p<0.01). The results of the mean comparison showed that the Aeluropus littoralis with average values of 0.636 and 10.1 had a higher preference index and grazing time by livestock than that for other halophyte species, respectively. Also, in terms of livestock behavior for both factors, the highest grazing time was observed in October followed by November. The results of the species by grazing season interaction effect showed that the Salsola crassa and Aeluropus littoralis had higher preference indices for grazing whereas Seidlitzia rosmarinus and Aeluropus littoralis had longer times of grazing. According to the results of this research, the timing method was introduced as an appropriate method to determine the preference values of halophyte species in the studied area.