Management effects on vegetation characteristics of pastures in north of Iran

In this study some characteristics of vegetation, including canopy, plant composition, forage production and pasture condition in the pastures with different management including the grazed, short-term exclosure and long-term exclosure pastures located at watershed area in Kojur River in Chaloos-Iran were studied. To study the vegetation in each Pasture, four transects with 50 meters were located the randomized-systematic method and in each transect the characteristics of vegetation in 10 plots with 1 square meters were compared and classified using ANOVA and Duncan test. The results showed that the long-term exclosure pasture had the highest percent of canopy with 83% and the lowest percent was related to the grazed pasture with 55%. Also the highest percent of vegetations in class I in the short-term exclosure pasture and in class III in exclosure pasture have been 46% and 49%, respectively. The highest forb covering in the short-term exclosure pasture and the highest covering of bush plants in the long-term exclosure pasture were obtained 38% and 30%, respectively, that the results obtained were statistically significant at the 5% level. The amount of forage production in short-term exclosure pasture was increased 67% compared to the grazed pasture and in the long-term exclosure pasture was increased 2.5 times the grazed pasture. This study showed that the short-term removal of livestock grazing in semi-humid region has provided the opportunities required for growth of various species, especially species that were more pressured by livestock grazing and didn't have the opportunity for presence. But by the removal of livestock grazing in the long term, due to competing among species and making balance the ecosystem some species are removed and the number of species was decreased compared to the early stages of succession.