Farhad Aghajanlou; Peyman Akbarzadeh; Alireza Eftekhari
Volume 31, Issue 4 , January 2025, , Pages 323-346
Abstract
Background and Objectives
Growing awareness of environmental issues and sustainable natural resource management require continuous study and monitoring across various timescales and locations. Ecosystems, including rangelands, undergo constant change. Given their ecological significance, economic ...
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Background and Objectives
Growing awareness of environmental issues and sustainable natural resource management require continuous study and monitoring across various timescales and locations. Ecosystems, including rangelands, undergo constant change. Given their ecological significance, economic role, and vulnerability to irreversible alterations, rangeland monitoring is essential for their ongoing assessment.
Research Methodology
This study monitored changes in vegetation cover and soil indicators over five years at the Dagestan site in Zanjan Province. Field evaluations included plant and soil factors. Plant-related data encompassed canopy cover percentage, litter percentage, species density (where applicable), production, rangeland condition, and trend. Assessments were conducted using established methods, with adequate sampling and proper distribution across different plant communities during both initial evaluation and subsequent monitoring. Soil factors included pH, electrical conductivity, nitrogen, phosphorus, potassium, organic matter content, bulk density, and soil texture.
Results
Statistical analysis of vegetation changes and their effects on soil indicators under grazing and flooding over the five years revealed significant differences in most parameters. Total canopy cover and rangeland production differed significantly between years and site types (grazed vs. exclosure) at the 1% and 5% probability levels, respectively. The highest vegetation cover (56%) was observed in the grazed area in 2018, while the lowest (30%) occurred in the exclosure in 2021. Peak total production (126 g m<sup>-2</sup>) was recorded in the exclosure in 2018, while the lowest (48.7 g m<sup>-2</sup>) occurred in the exclosure in 2021. Total species density showed no significant differences between years, site types, or their interaction. However, on average, shrub density was higher outside the exclosure, while grass density was higher inside, indicating a significant difference. Vegetation changes due to grazing and flooding affected certain soil parameters. Increased grazing intensity correlated with decreased potassium, phosphorus, nitrogen, organic carbon, and electrical conductivity in the topsoil.
Conclusion
Over the five-year study period, grazing significantly influenced vegetation, and the decline in vegetation cover had a notable impact on soil physical and chemical properties. Vegetation changes in the study area were gradual and shaped by rangeland management practices. Regular monitoring of qualitative and quantitative changes in rangeland vegetation is essential for informed planning and the implementation of effective management strategies for sustainable rangeland use.
morteza Khodagholi; Razieh Saboohi; Alireza Eftekhari; Mina Bayat
Volume 31, Issue 4 , January 2025, , Pages 363-381
Abstract
Background and purpose:Increasing awareness of the environment and efforts for sustainable management of natural resources require study and monitoring in different time scales and places. Continuous changes should be considered as an inseparable part of any ecosystem. As natural ecosystems, rangelands ...
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Background and purpose:Increasing awareness of the environment and efforts for sustainable management of natural resources require study and monitoring in different time scales and places. Continuous changes should be considered as an inseparable part of any ecosystem. As natural ecosystems, rangelands are not exempt from this issue. So that rangeland monitoring is necessary in the sense of continuous investigation of these lands with regard to the ecological importance, economic functions and constant changes of these resources. Access to such data is extremely important both for national planning and for the use of rangelands, and it provides the basis for the use of advanced facilities such as remote sensing. Based on this, in order to monitor the trend and intensity of changes in vegetation cover and soil indicators of rangelands for 4 years at the Goorab site located in Isfahan province, it was evaluated and monitored.Materials and methods:The site of Goorab Fereydoonshahr Isfahan is located 230 kilometers west of Isfahan city and 35 kilometers west of Fereydoonshahr city. Plant factors including canopy cover of plant species and production rate of plant species and percentage of dead leaves were evaluated. Evaluation was done in the first year by random-systematic method and in the following years systematically with sufficient number of samples and appropriate distribution of samples in the plant type determined at the time of rangeland preparation. Soil sampling was done in theResults:The results showed that the 4-year average vegetation canopy cover percentage of Goorab site is about 42.2%, and the highest and lowest coverage is 59.4% in 1398 and 31.6% in 1400, respectively. The production rate is 1374.2 kg of dry matter per hectare. The production, like the canopy cover percentage, shows a lot of changes during the 4-year evaluation at the Goorab site, so that in 2019, the production reached 1957 kg per hectare, and in 2021, it decreased by 50% compared to 2019 to 955.7 kg per hectare. The results of the correlation and regression test also showed that the amount of precipitation in the growing season had the highest correlation with the amount of crown cover and production of plants in the region.Conclusion:Considering the importance of rangelands, both in terms of production and in terms of environmental values and services they provide to the society, studying the changes of rangelands in terms of the aforementioned factors and knowing the factors of those changes will be an effective help in developing a basic management plan and sustainable use of rangelands.
Hasan Ghelichnia; Alireza Eftekhari
Volume 31, Issue 1 , June 2024, , Pages 28-52
Abstract
AbstractBackground 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 ...
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AbstractBackground 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.
Zahra Jaberalansar; Babak Bahreininejad; Alireza Eftekhari; Masoud Borhani
Volume 30, Issue 3 , January 2024, , Pages 424-440
Abstract
Background and objectivesThe study of vegetation changes under habitat protection conditions has a significant role in rangeland management. The studies confirm that permanent changes in rangelands in terms of plant composition, canopy cover, and forage production are influenced by ecological and management ...
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Background and objectivesThe study of vegetation changes under habitat protection conditions has a significant role in rangeland management. The studies confirm that permanent changes in rangelands in terms of plant composition, canopy cover, and forage production are influenced by ecological and management factors. This research was conducted to investigate and monitor the plant vegetation indices of semi-steppe rangelands of central Zagros for five years (2016-2020) at the Zayandehrud watershed management research site (Isfahan province). Methodology Vegetation sampling was performed by a systematic random method in each exclosure and grazed site during 2016-2020. Vegetation characteristics, including the percentage of canopy cover of species, the percentage of gravel, bare soil, and litter were determined in each plot. For this purpose, four 100-meter segments were used. Then, ten plots (with 1 x 1-meter dimensions) were established with the same distance. In total, vegetation cover was measured in 80 plots of one square meter in exclosure and grazed sites. To calculate rangeland production, ten samples of each plant species were collected, and their canopy cover percentage was measured. After drying and weighing the samples, by establishing regression equations between the canopy cover percentage and the weight of the dried samples, the amount of production of plant species was determined separately for growth form and palatability class. Rangeland's condition was also evaluated according to the four-factor method and by scoring the factors of soil, vegetation, plant composition and age classes, and plant vigor. After collecting the data in Microsoft Excel, the variance analysis for the vegetation traits was done as a completely random design in a factorial format. This was done through the GLM (General Linear Model) method. Tukey's test investigated vegetation traits mean comparison in MINITAB 16 software. ResultsThe analysis of variance showed a significant difference between vegetation indices, including total canopy cover and production, separately for growth form and palatability class. This was in the exclosure and grazed sites during the assessment period. The average percentage of canopy cover in exclosure sites during different years was 26.7%, 13.7%, 25.84%, 33.74%, and 13.33%. In grazed sites, it was 22.33%, 12.65%, 27.09%, 30.9%, and 11.59%, respectively. Total production at the exclosure site during different years was 624.26, 349.86, 556.79, 894.54, 664.53 kg/ha. Production at the grazed site was 456.45, 243.85, 455.6, 605.47, and 323.44 kg/ha, respectively. The highest values of canopy cover and production belonged to 2019, which was a wet year based on meteorological indices. The lowest canopy cover and production were assigned to 2017 (a drought year). The highest amount of litter was found at the exclosure site. The highest percentage of bare soil and annual plant canopy cover was obtained from the grazed site. The highest percentage of canopy cover and production in the exclosure site belonged to Stipa hohenackeriana. At the grazed site, Hedysarum criniferum and Stipa hohenackeriana accounted for the highest canopy cover and production, respectively. According to the four-factor method, the rangeland condition at the disclosure site was fair in 2016, 2018, and 2019 and poor in 2017 and 2020. At the grazed site, the rangeland condition was fair in 2018 and 2019 and poor in the rest of the years. Conclusion The comparison of vegetation parameters inside and outside the exclosure shows the good condition of vegetation inside the exclosure. It also shows the effectiveness of the exclosure in rangeland rehabilitation. Balanced livestock grazing on the vegetation caused no significant difference between vegetation characteristics, such as canopy cover in the exclosure and grazed sites. Continuous evaluation and monitoring of rangelands through creating a regular database of vegetation indicators and investigating their changes under different managements. This investigation of their relationship with climatic factors can provide the necessary background for fundamental rangeland planning and management.