فصلنامه تحقیقات مرتع و بیابان ایران
سال بیست و نهم شماره 2 (پیاپی 87، تابستان 1401)

Calculating rangeland capacity and determining the allowable use for important rangeland species is necessary for sustainable range management. By having the rangeland capacity and presenting accurate management plans, the destruction of vegetation and soil and the reduction of water resources can be prevented. Suitable grazing intensity causes continuous and economic use in the rangeland. Therefore, a study was conducted on the effects of different harvest intensities on forage production of three species Halocnemum strobilaceum, Desmostachya bipinnata, and Aeluropus lagopoides Hormozgan province three years from 2008 to determine the most appropriate level of exploitation. Experimental treatments included four harvesting intensities of 25, 50, and 75% and control (without harvest). In each treatment, ten rootstocks of the species were considered replicates and evaluated on each of the dependent variables. The results were analyzed in SAS software. The results showed that harvest intensity affected the forage production and all treatments were significantly different from the control. Therefore, up to 50% of the allowable use for Aeluropus lagopoides and Desmostachya bipinnata, and up to 75% for Halocnemum strobilaceum is suggested to maintain the health and vigor of these species during the harvest years. According to the above findings, this allowable use can be considered for similar areas in terms of climate together with information about other plants.

This study aimed to investigate the effect of restoration projects on soil surface indicators and performance characteristics in Taherabad rangelands of Ferdows. The Landscape Function Analysis method was used to determine soil surface properties and yield potentials. In this regard, in the representative area of each treatment, three transects (each for 100-meter) were settled at specified distances along the main slope. Along each transect the length and width of plant spots and the length of the inter-spot distance were measured. Excel and LFA (Landscape Function Analysis) instructions were used to calculate the performance potentials. To examine the significance of the performance potentials, SAS software was used in this study. According to the results, there is a significant difference between the treatments. The highest percentage of stability was estimated in the arc basin + exclusion and the lowest was in the treatment of the control area; also, soil infiltration of different restorative treatments, significant differences, and the highest and lowest percentages of soil infiltration was estimated in the arc basin + exclusion and control projects, respectively. The results showed no significant difference in the Nutrient Cycling Index and soil mineral elements in different rangeland restoration projects. Landscape Organization Index for arc basin + exclusion, planting + exclusion, exclusion and control were estimated to be 0.33, 0.22, 0.18 and 0.14, respectively. The Kruskal–Wallis test showed a significant difference (at a 5% level) between the soil surface indicators at different rangeland restoration projects. It is concluded that there are significant differences among soil surface indicators, collar and canopy, litter, soil surface fragility, erosion type and intensity, eroded materials, nature of soil surface and wetting test at 5%, and texture at 1% in different restoration treatments. Different treatments have caused differences in these indicators. Also, there is no significant difference between cryptogam and microtopography indicators. In general, arc basin +exclusion construction in arid and semi-arid regions is a useful restoration activity and increases soil stability and infiltration.

One of the objectives in rangeland management is the accurate and rapid determination of forage production to determine grazing capacity. The relationship between forage production and morphological characteristics was investigated in this study. For this purpose, two grazed and non-grazed units were selected in the mountainous rangelands of Nazlouchay, Urmia. In each of them, the morphological characteristics of A. aucheri, as the only dominant plant species that accounts for more than 50% of the plant composition, were measured within 60 one-square-meter plots located along with 100-meter transects in July 2017. After cutting off bases growth, the dry weight of the samples was determined, and its regression relationship with morphological characteristics was examined using hierarchical regression. The results showed that it was possible to estimate A.aucheri  production in the unit where the plant bases were not grazed using multiple linear regression models based on diameter, average crown size (D1), collar diameter (D2), and height (H). In the grazed units, where plant bases were grazed in the fall of last year, only the average diameter of the crown (D1) and height (H) was validated with multiple linear regression models, as the best model with RMSE equal to 3.53 and coefficient of 0.52. Due to the relatively good performance of the model and the preference for combining several morphological features in production estimation, separating models into inside and outside the exclosure can play a role in rangeland monitoring and production estimation to calculate grazing capacity and assess the intensity of rangeland utilization.

This study aimed to identify the economic, social, and ecological indicators affecting the beekeeping model in rangelands in the Sarayan region of South Khorasan province. This research is applied in terms of purpose, descriptive-analytical method, and quantitative in terms of data collection. The statistical population of the study included all ranchers in the Sarayan region. Using Krejcie and Morgan's table, 180 ranchers were selected by random sampling method. The data collection tool and information were a researcher-made questionnaire designed to assess the tendency of pastoralists to beekeeping in the rangeland and determine the main indicators of their unwelcome to this type of livelihood using a semi-structured interview method. The reliability of the questionnaire was 0.86 using Cronbach's alpha test. The results showed that in 61.7% of ranchers, the tendency to beekeeping was reported to be high and very high. So that there is a significant correlation between age (at 99% level), level of education (at 99% level), and percentage of rangeland dependence (at 95% level) with a tendency to beekeeping in rangeland. However, this correlation was negative for age and percentage of rangeland dependence. The results of ranking the important indicators of ranchers' reluctance to beekeeping also showed the indicators of knowledge, insufficient knowledge and skills, the safety of hives in the rangeland, low risk-taking spirit, and rangeland ownership as the most important social indicators, cost of providing, transferring and maintaining hives in the rangeland. The most important economic indicators and short indicators of the rangeland flowering period, poor vegetation, lack of sufficient water resources, and environmental risks (drought, storms, pests, and diseases) were considered the ecological indicators from the perspective of rangers.

Wind erosion and dust storms are one of the natural disasters that are increasingly facing the arid and desert areas of central Iran. Improper management in natural resources has also had a high impact on this phenomenon. One of the basic principles of controlling and combating wind erosion is to know the areas of sediment harvesting. The purpose of this study is to identify the areas of wind sediment harvesting in the facies of the Mallard region in the west of Tehran province. Based on topographic maps, satellite imagery, geological map, and field surveys, the geomorphologic facies map was prepared and then the sampling was done and analyzed in a GIS environment. The interpretation of the anemometer data using Windrose & Stormrose showed the wind direction of the dominant and eroding from the northwest. The results obtained from the study's Sandrose indicated that variation in wind direction is low to high, and Qazvin station (the station closest to the critical centers) had high variability and included multi-directional winds with sharp angles. The 83 samples of different facies of the study area are graded by the ASTM (Dry Sieve) method. The granulation results indicate the local origin of the harvest. The prioritization map of the critical centers of the region showed that 16.4% of the area is low intensity, 3.4% medium intensity, and 3% high intensity. Finally, it was found that saline clay with no vegetation cover or with little vegetation covered with saline in the plain had the highest percentage of particles sensitive to wind erosion.

The increase in greenhouse gases emission over the last century has led to perturbation in the carbon cycle and has increased concerns. Therefore, the present study evaluated rangeland biological rehabilitation practices with native and cultivated plant species on carbon sequestration in Dehaghan region bushlands. For this purpose, two biological projects, including seeding Agropyron trichophorum in the Glisar region with a 17-year-old record and pit-seeding of Prangos ferulacea with a 10-year-old record in the Astane Sefla region were evaluated. Soil and plant sampling was carried out in the spring of 2013. Afterward, the carbon concentrations in soil and plant samples were evaluated based on Walkley black and Combustion Methods, respectively. Results also showed that the carbon sequestration capacity in the seeding of A. trichophorum in the Glisar region and pit-seeding of P. ferulacea in the Astane Sefla region has increased to 37.4 (on average 2.2 ton/ha/year) and 10.1 (in average 1.01 ton/ha/year) comparing to control region, respectively. In general, A. trichophorum seeding project has been more successful than P. ferulacea pit-seeding in terms of increasing carbon stabilization. The results also showed that Astragalus verus and Bromus tomentellus species have a high potential for carbon stabilization compared to many rangeland species in rangeland improvement projects.

Understanding the ecological characteristics of plant species and how they react to environmental factors provides the necessary information for vegetation management and rangeland improvement. In the present study, the ecological needs of sainfoin (Onobrychis melanotricha Boiss.) were studied with emphasis on environmental factors affecting vegetation changes, and the response of this species to changes in ecological factors was investigated using the Canonical Correspondence Analysis (CCA). Data collection was performed in 2018 in 19 study sites in the west and south of Isfahan province. In each site, the vegetation sampling was performed by random-systematic sampling method in 30 plots of one square meter, located along 3 200-meter transects, and soil sampling was done from a depth of 0-30 cm in each site. Data were analyzed using SPSS17 and CANOC4.5 software. Using a generalized additive model with Poisson error distribution for each of the environmental variables showed that environmental factors including height, clay percentage, rainfall, organic matter percentage, phosphorus, and sand percentage, and the average annual temperature significantly affect (p<0.01) vegetation. This species is distributed on semi-deep to deep soils with medium to semi-heavy textures. This species is distributed on semi-deep to deep soils with medium to semi-heavy textures. The optimal altitude range for the growth of this plant was 1600-3200 meters above sea level, and the optimal rainfall for this plant was 370 mm. Overall, the results of this study had an acceptable efficiency in determining the ecological needs of the species, which can be considered by natural resource managers in vegetation management and rangeland improvement operations in similar areas.

Different rangeland management measures such as fencing and improvement can provide the potential for their restoration. This study aimed to investigate the effect of a range of rangeland management measures including fencing, remediation, and grazing on some soil properties in the rangelands of Kurdistan province. We established 25 plots of 1×1 m2 each along two transects with 240 m length (120 m perpendicular to the slope and 120 m parallel to the slope). At each plot center, soil samples (0-15 cm depth) were taken, together with other attributes comprising litter, vegetation, bare soil, and gravel percentages. This resulted in 75 soil samples from three study areas. Furthermore, some chemical soil properties were analyzed in the laboratory after drying and preparing the soil samples. We used one-way analysis of variance (ANOVA) to analyze the data, as well as Pearson correlation to study the relationship between the parameters. Results revealed statistically significant differences in some soil properties amongst the study areas. In addition, the amount of soil carbon (1.94%), nitrogen (0.205%), C/N ratio (9.48), phosphorus (288mg/kg) and potassium (129 mg/kg) showed the highest rates in the improvement area, whereas all those parameters including carbon (1.25%), nitrogen (0.179%), C/N ratio (7), phosphorus (170mg/kg) and potassium (75 mg/kg) showed the lowest rate across the grazing rangeland. Further, pH (8.27) and EC (174 µs/cm) showed the highest levels in the grazing area. The results of the Pearson correlation showed that the percentage of vegetation was significantly and positively related to all soil properties except pH and Ec. In addition, bare soil and gravel percentages indicated a significant negative relationship with soil carbon, nitrogen, phosphorus, and potassium. We conclude that fencing and rangeland remediation treatments can enable significant positive effects on soil nutrients that are essential for plants.

Awareness of knowledge and attitude of rangeland owners towards the problems and management of this ecosystem is essential for decision making and planning. The purpose of this study is to evaluate the views of rangers and natural resources experts on the impact of the implementation of rangeland projects as well as their participation and cooperation in the success of these projects. The study area was the city of Torbat-e Jam. Examining the rangeland management plans of Torbat-e-Jam city from 1993 to 2014, it was found that five plans in Bashirabad, Cheshmeh Gol, Goyi, Timanak Sofla, and Jahanabad areas have been implemented. The statistical population of the study includes 464 farmers who are pastoralists with grazing licenses. Using Cochran's formula, 186 samples were systematically randomly selected and questioned. Then, from the statistical analysis of the data and by examining all the measured variables and components, it was found that there is a significant linear relationship between the views of regional stakeholders and economic, educational, social participation, and institutional cooperation. The results showed that the most important components affecting the view of stakeholders to participate in rangeland projects are the study of economic and social needs before the approval of projects and approval of projects following the needs of villagers, including income and housing, and selection of executors from among stakeholders. It is suggested that to improve the results of watershed management projects in the study area, continuous coordination between the extension departments of the cities to hold orientation, training, and cooperation-oriented classes in the field of proper rangeland management should be on the agenda.

Desertification is a serious ecological, environmental, and socio-economic threat to the world, and there is a pressing need to develop a reasonable and reproducible method to assess it at different scales. Therefore, in the present paper, changes in cover and desertification of Kashan, Aran and Bidgol regions in the north of Isfahan were developed using Landsat ETM and OLI data. According to this research, NDVI (Normalized Difference Vegetation Index), TGSI (Topsoil Grain Size Index), and land surface albedo were selected as indicators for representing land surface conditions from vegetation biomass, landscape pattern, and reflection. A Decision Tree (DT) approach was used to assess the land cover change and desertification of the study area from 1995-2020. Temporal changes indicated an increase in NDVI, TGSI, and albedo trends during this period. The spatial distribution of NDVI showed that values greater than 0.5 were observed only in a small part of the west and southwest, while high values of TGSI and albedo occupied a large area of the study area. There was also a correlation between the above three indicators at 95% (R = 0.99). The results also showed that desertification is increasing in the study area, so that the intensity of desertification from 1995 to 2020 in classes without desertification was low, medium, and severe. The high desertification class decreased by 1420.75 square kilometers (13.54%), while severe desertification increased by approximately 1388.8 square kilometers (13.23%). The highest NDVI values were found in the non-desert area and the low desertification class, while the highest TGSI and albedo values were found in the high and severe desertification classes.