Document Type : Research Paper
Authors
Abstract
This study aimed to evaluate the range suitability for sheep grazing according to the Manual of Suitability for Sheep Grazing instructions in the rangelands of central Taleghan and comparison with the FAO guidelines (1991). Accordingly, the final model of range suitability was determined from combining three criteria of vegetation, water resources and soil erosion. Sampling was conducted in the key area of vegetation types through random-systematic method with four transects of 200 meters and 40 plots of one square meter and in each plot, the list of species, canopy cover percentage, and species composition as well as production were harvested and calculated. For this purpose, the results of the proposed instructions were compared with the results of the FAO model (1991) by non-parametric Wilcoxon test. Our results clearly showed that the lack of available forage, low allowable use, erosion and the formation sensitive to erosion (Marl), poor condition and negative trend in some vegetation types as well as steep and mountainous regions were among the factors, limiting range suitability for sheep grazing. The final results of sheep grazing model showed that no vegetation type was placed in S1 and N classes, and most of the vegetation types of the study area was in S2 range suitability class, so that from 25576.9 ha of the rangelands studied, 87.25% was in S2 class and 12.75% was in S3class. According to the results of comparison of the two methods for determining range suitability, no significant differences were found (P <0.01).
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