Grazing management effects on plant functional groups in Sahand summer rangelands, Northwest, Iran

Aim: This study was conducted to compare the effects of three types of light, medium, and heavy grazing intensity on the plant functional groups across the Sahand summer rangeland. Materials Methods: First, three areas with different grazing intensities were selected according to the field observations and collected information from herders. Then, the random systematic approach was applied to plant sampling across the selected sites. Afterward, six transects were randomly established in the selected sites separately, where ten plots were then localized on the compounding transects. Finally, the properties of plant functional groups were captured on the plot scale. Findings: The results of the Duncan test indicate a significant difference in the average production, canopy cover percentage, and litter percentage across the studied sites under different grazing intensities. The average characteristics of all plant functional groups in sites with different grazing intensities have a significant difference at the level of 1%. In this regard, the highest averages with 487.8 kg. ha-1, 62.7%, and 12.5% are related to the site with light grazing, respectively. Results revealed that the properties of perennial grasses and forbs in the region under light grazing intensity are higher than two other studied regions, which were under medium and heavy grazing. Conclusion: The finding of this research implied that the livestock grazing intensity could significantly affect the palatability classes and growth form of plants. Therefore, changes in grazing intensity are recommended as a management tool in rangeland improvement to improve vegetation characteristics and move vegetation towards equilibrium.