| Abstrakt: |
Background and objective: The monitoring and evaluation rangelands provides the necessary information for the essential planning of rangeland management. As a result, it prevents the destruction of rangelands and water and soil conservation. This research aims to prepare a continuous database of vegetation and soil indicators in rangelands and monitor their changes, determine the relationship between vegetation indicators and climatic factors, determine the trend and intensity of changes in different managements, and provide information for calculating the long-term capacity of rangelands. Methodology: For this study, the Asbchar site was selected in the rangelands of the Baladeh region in Mazandaran province and was evaluated and monitored for five years (2017-2021). In order to evaluate the indicators of vegetation cover, three transects of 100 meters were placed at a distance of 50 meters from each other. Vegetation and soil factors were measured. Vegetation factors included canopy cover, density and production of plant species, litter, rangeland condition and trend. Soil factors include pH, E.C., nitrogen, phosphorus, potassium, organic matter, soil bulk density and soil texture. Ten plots of 1m2 were placed in each transect, and a total of 30 plots were placed in exclosure and grazed areas. The crown cover of any plant species with the method of measuring the crown surface, the density by counting the number of species, the production by cutting and weighing, and the percentage of stone and gravel cover, litter, and bare soil were also measured in the plots. Data testing was done in Minitab16 software. Results: The analysis of variance results has shown a significant difference between most vegetation and soil factors in different years. The comparison of the averages of vegetation and soil factors investigated in different years shows that the highest average percentage of the total cover was related to the exclosure region. The highest average value was related to 2010, 2021 and 2019, respectively, and the lowest was the year 2017. The correlation between the total cover of the exclosure region with the total production, the percentage of nitrogen inside and outside the plant, the amount of potassium outside the plant, the annual rainfall, the rainfall of the growing season and the rainfall of autumn and winter seasons in exclosure region is significant. Also, the correlation between total production and annual rainfall, rainfall in the growing season and rainfall in autumn and winter seasons is significant. The correlation between total cover with total production, nitrogen percentage under plants, annual rainfall, growing season rainfall and autumn and winter rainfall in the grazed area is significant. Also, the correlation between total production with rainfall in the growing season and rainfall in the autumn and winter seasons is significant. The step-by-step regression results showed that climatic factors such as growing season rainfall, total fall and winter rainfall, and soil factors such as E.C., pH, % O.M. and %N were used to predict the total cover and production. Conclusion: The results of this research show a significant difference between the total crown cover, production and density of species during five years. Also, there is a significant difference between the exclosure and grazed areas in terms of all the factors examined in this research. The percentage of coverage, production and density of the perennial grasses and forbs in the exclosure region was higher than in the grazed region. The research results over five years showed that when autumn and winter rainfall and total rainfall and rainfall in the growing season were greater, an increasing trend was also seen in vegetation characteristics. [ABSTRACT FROM AUTHOR] |
