فصلنامه تحقیقات مرتع و بیابان ایران
سال بیست و هشتم شماره 2 (پیاپی 83، تابستان 1400)

In the current era of participation, the rule of common sense and the involvement of all stakeholders in key decisions have been accepted. Targeting and directing partnerships to conserve and rehabilitate natural resources will lead to sustainable development. The concepts of participation and the affecting factors need to be explained and studied. The aim is to investigate the factors affecting the participation of local communities in natural resource management from the perspective of experts in the region, Kerman. The research is descriptive-analytical, and the survey technique is used. Necessary information has been collected by completing 40 questionnaires from all natural resources experts of the province and the project (RFLDL) in the form of a census. The research tools of the questionnaire and its validity have been approved by experts. Using Cronbach's alpha coefficient, the reliability coefficient for the questionnaire items was determined to be 0.84. The reliability of the research items was measured by Cronbach's alpha statistic, the results of which (coefficient 0.84) indicate the high reliability of the items for measuring variables. Multiple regression tests have been used to determine the share of factors (eocnomic, extension, educational and managerial) on the participation of users from the perspective of experts.  The results showed that social factors had a much greater share in predicting the dependent variable than other variables. Based on the results, giving importance to social factors can play an important role in attracting the participation of rangers in rangeland management.

In this research, the preference value of rangeland species in Sahand rangelands of East Azarbayjan province was studied for four years (2007-2010). The preference index method was used for this purpose. After determining the amount of production and consumption of each species selected in the grazing season (June, July, August, and September) and calculating the share of each species in the forage production of the region and livestock feed, and calculating the preference index, the data analyzed in split-plot design based on the completely randomized design in SAS software. The results showed that the effect of the year in three species, the effect of the month in four species, and the interaction of year and four species at (p≤0.01) were significant on the preference index. The preference index is a very important factor in determining the preference value of plant species for livestock. The species of Festuca rubra, Tanacetum chiliophyllum, with an average preference index of 1.4 to 1.6 during four-year, has a relative preference and is a relatively benign species and was placed in the palatable class I. Tanacetum chiliophyllum, with the highest average preference index, was ranked first among all herbaceous species. The species of Bromus tomentellus, Festuca ovina, Alopecorus textilis with an average preference index of 0.7 to 1.2 were of moderate preference and were classified as moderate in palatability and classified in the palatability class II.  Astragalus aureus, with an average preference index of about 0.3, had a relative preference, and this species was almost non-chewed and ranked in the palatable class III. Overall, the results of this study showed that the preference value of Festuca rubra and Tanacetum chiliophyllum was more than the other species, and the sheep preferred the forbs, followed by grasses and shrubs for sheep grazing.

Cymbopogon olivieri is a perennial grass in tropical regions. This species has very high compatibility in the rangelands of Khuzestan province by benefiting from type C4 photosynthesis. This species is specific to warm areas. The variation in the habitats of this species causes differences in phenotypes and forage yield of its populations. In order to evaluate the populations of Cymbopogon olivieri species, at first, the addresses of herbarium were studied, and its habitats in Khuzestan province were identified by field surveys. Then, at the appropriate time, the seeds of seven identified populations were harvested from different habitats of the province and were planted in the Baghmalek research station and evaluated for three years (2011-2014) after establishment.  To measure the traits from each population, at the stage of spike emergence, aerial parts of plants were harvested in three plots of 3 m2 from a height of 5 cm above the ground. After counting the number of tillers and plant height, they were dried and weighed in an oven at 70 ° C for 48 hours to determine dry forage yield, aerial parts. There was a significant difference between the studied populations for dry forage yield, plant height, and the number of tillers. The highest forage yield of Cymbopogan olivieri in the third year after the establishment of populations collected from Dezful-Dez Dam, Masjed Soleiman-Bardemar and Ahvaz-Masjed Soleiman route with a production of about 110 g dry m-2 and then Shushtar -Abgah, and Dezful- Shahion with a production of about 100 g dry m-2 respectively. In terms of plant height, populations related to Dezful-Dez Dam, Shushtar-Abgah, and Dezful-Sardasht-Gavmir with a longitudinal growth of more than 50 cm were statistically superior. In terms of mean tiller number per plant, the Dezful-Dez dam population with 125 tillers had the highest and the Ahwaz-Masjed Soleiman route population with an average of 69 tillers had the lowest tiller number per plant.

This study was conducted to study species diversity changes in Chaharbagh mountain rangelands of Golestan province in five different managed sites, including non-grazing (enclosure), intermediate grazing (key), and critical (village vicinity, watering point, and pen area). Numerical and parametric diversity indexes were calculated by collecting vegetation data. One-way ANOVA results showed that exclusion and key sites were better for the Shannon diversity index (2.6 and 2.1, respectively) than critical sites; however, no differences were found in the Margalef richness index. A higher ranking of diversity site of the key site indicates that it is more diverse than the restricted site. By fitting the frequency distribution models, it was determined that the exclusion and key site were related to the log series models (stable communities), and the critical sites were related to the geometric series model (unstable communities) at the 0.05 level. Frequency-rank curve plotting indicated that high grazing sites had rare and dominant species with high numbers indicating the effect of grazing pressure; however, moderate sites and high grazing sites have high evenness. Overall, the results showed that moderate grazing preserved the vegetation diversity, and exclusion had no significant effect on increasing vegetation diversity in rangelands. This result confirms the need to pay attention to moderate grazing in the field. Among the critical sites, the village privacy site is in a worse situation, and livestock grazing intensity should be reduced due to the proven effective role of medium grazing in the region to rehabilitate sites with high grazing intensity, especially in rural areas. Reducing livestock density in critical areas by increasing the number of water sources and rest areas in the field will be one of the methods to help reduce damage to plant diversity of critical sites.

Rangelands as the main part of natural resources are considered a basis for the economic growth and development of communities and countries at the micro and macro levels. Increasing the number of livestock has led to the degradation of rangelands, so it is necessary to control grazing. The purpose of this study was to investigate the effect of the implementation of rangeland management plans on the production and economic status of summer rangeland owners in Aminabad and KourAbbasloo, Nir city, Ardabil province. To determine the BCR, the economic evaluation of the plans, and their impact on the income of ranchers, data was collected by questionnaire. The results showed that there was a significant difference between income before (4.16 million Rials/ha) and after implementation of the rangelands plan (5.46 million Rials/ha) at (p < /em><0.01). There was a significant difference at (p < /em><0.01) in the amount of production before and after the project implementation with the amount of (293.05 kg ha-1) and (411.6 kg ha-1) respectively at KourAbbasloo rangelands in the third period of the implementation of the plan. Regression analysis showed that the two variables of the effect of project implementation on rangeland status and the effect of loan payment on rangeland plan implementation were able to justify 72% of changes in users' satisfaction with the implementation of the rangeland management plan. The results of the economic analysis of the rangeland plan implementation showed that the project has a positive net present value of 6439 million Rials ha-1. It has also generated a BCR of about 5.5 times. Overall, the results of this study showed that the rangelands with management plans had better conditions than without ones in terms of production and economics. Implementation of rangeland management plans can increase production and improve rangeland status and income of landholders if it is in line with ecological, economic, and social conditions of the rangelands.

The complexities of the relationship between biodiversity and human welfare can be simplified by identifying the impact of species diversity on ecosystem function. Since annual production plays an important role in the grazing management and sustainability of rangeland ecosystems, this study examines the relationship between species diversity and annual production of semi-arid rangelands in Khabar National Park under the hypothesis of ecological nest. The annual production of species in 1×1 square plots was estimated in two rangeland types of Artemisia sieberi and Artemisia sieberi- Stipa barbata using the cutting and weighing method. The results showed that although the two plant types differed significantly in terms of annual production (p < /em> <0.05), but there was no significant difference between the two rangeland types in terms of diversity indicators of Shannon, Simpson, Margalf, Manichae, and uniformity index. Pearson’s correlation analysis showed that annual production had a positive and significant relationship with species diversity indicators in Artemisia sieberi- Stipa barbata type; however, no significant relationship was observed in Artemisia sieberi. Contrary to the hypothesis of the ecological nest, species did not have the same contribution in annual production, and the dominant species of Artemisia aucheri had the highest contribution in production. According to the hypothesis of mass ratio, the diversity of functional traits in the dominant species has led to better success of rangeland type the Artemisia aucheri- Stipa barbata than the Artemisia aucheri in terms of annual production. In general, it is recommended that conserving of the composition of plant communities is more important to protect ecosystem services compared to maintaining the maximum number of species.

The use of polymers to control wind erosion has been considered in recent years. However, before recommending them as mulch, their effects on the environment and reduction of wind erosion should be investigated. In this paper, the effect of Imen Asia polymer in stabilizing quicksands and reducing wind erosion in both laboratory and field sections in the Lower Jargooiyeh region was investigated. For this purpose, first, an emulsion of polymer in water with a ratio of one to three (one-part polymer in two parts water) was prepared and to investigate its effect on reducing erosion, a volume of emulsion containing 80, 100, and 120 kg of polymer in 25 m2 plots Sprayed with three repetitions. The results showed that the wind erosion threshold speed after mulching increased from 3.5 to more than 11 m / s in all treatments. The study of the environmental effects of the polymer showed that the concentration of mulch did not affect the germination of native plants and the lifestyle of insects and rodents in the area. The effect of polymer on the physical and chemical properties of soil, including changes in the number of toxic elements and heavy metals on the soil before and after mulching, also confirms that it does not have a negative effect on these properties. Economically, the cost of using this polymer per hectare was evaluated. Based on the net present value (NVP) of this material and its internal rate of return (IRR), the economics of using it and investing in the use of this polymer as mulch are justified. Due to the lack of harmful effects on the environment and the ability to reduce wind erosion and economical to oil mulch, the use of this polymer as mulch is recommended

Three perennial grasses Stipa arabica, Elymus pertenuis, Hordeum bulbosum, were selected under rainfed conditions in semi-steppe habitats of Fars province. Seeds of 15 populations of these three species (five species of each genus) were collected in 12 habitats and an elevation profile of 1700 to 2600 meters above sea level located in seven cities. Each population included 120 pots (1800 pots in total) at the preparation station, and seeds (three seeds per pot) were planted in pots. In the third year, after preparing the main land, seeds were sown in three rows in each plot based on a completely randomized block design. Necessary assessments were made after species emergence based on canopy cover, plant height, forage production, seed production, and longevity. The results showed that Hordeum bulbosum with 471.67 kg seed production and 539.20 kg forage production per hectare had the highest yield, and Stipa arabica species with 1642 cm2 and 92.60% had the highest canopy cover and vigor, respectively.

Taverniera cuneifolia is one of the most important palatable rangeland species in Hormozgan province that unprincipled and excessive exploitation has destroyed the natural habitats of this valuable species. Only careful planning and crop cultivation and observing the rotation frequency and promoting plant cultivation in the habitat can be an effective step to maintain the survival of this species. In this study, Taverniera seeds were collected from two habitats (Geno and Tezerj) and pre-emergence treatments were soaking in sulfuric acid for 15 minutes, soaking in sulfuric acid for 30 minutes, soaking in warm water (70 °C) for one hour, soaking in gibberellic acid solution at a concentration of 1000 mg/l for 24 hours, scarification with sand, soaking in a potassium nitrate solution at a concentration of 0.1 molar for 24 hours, soaking in normal water for 24 hours and control. According to the results, all treatments had a higher germination percentage than the control. Meanwhile, treatments placed in sulfuric acid for 15 and 30 minutes caused 100% seed germination and were superior to other treatments. Sulfuric acid treatment for 15 minutes had the highest germination rate, and sulfuric acid treatment for 30 minutes had the highest radicle and plumule length.

Agropyron pectiniforme and Elymus hispidus var hispidus are important and palatable species in Mazandaran province rangelands. This study aimed to select top populations for forage production and use them in rangeland breeding and rehabilitation programs. Seeds of native populations of Agropyron pectiniforme and Elymus hispidus var. Hispidus was planted in reticulated plastic trays and operated after emergence for a short period. In early spring, in the area of Poshtkuh research station in the southeastern altitude of Sari, were planted on two lines (repetitions) with a length of 20 meters so that 40 plants of each accession were placed on the planting line. Their distance on planting rows was 0.50 m, and the distance between the lines was considered one meter. The experiment was conducted during the years 2011-2015. In the first and second year, no plant data were recorded because of plant establishment. Evaluation criteria for plant selection were plant height at the time of cluster emergence, canopy cover, survival rate, forage production and seed production. Different phenological stages including vegetative stage, flowering, seed formation and fall regrowth were recorded in 7-10 days. The obtained data were statistically analyzed in SPSS16 software. The results of combined analysis of variance of data related to the performance of the evaluated factors showed that there was a significant difference at the (p < /em><0.01) between the populations of the studied species in terms of forage production yield, longitudinal growth, canopy cover, survival percentage, seedling strength, and seed production. There was no significant difference between different years in terms of the studied factors. There is a difference between some populations of the studied species in terms of phenological stages and these populations; the phenological stages have a delay of about seven days. Therefore, to produce and strengthen forage vegetation, the seeds of these populations can be used in the mountain rangelands of Mazandaran province.

In this study, the initial assessment of carbon storage in plant communities of Lycium depressum Stocks and Zygophylum fabago L. was done in the Meyghan playa, Arak. Plant sampling was done by the random-systematic method. To determine the aboveground and underground biomass, a clipping method was used, and these organs were weighed separately. The organic carbon of plant samples was determined by the ash method. Soil studies were performed in each plant type, in the depth of plant rooting, as well as in areas without plants. The data were analyzed by SPSS24 software. The results showed that the soil and plant average carbon sequestration of Z. fabago habitat was 14.61 and 0.18, and in L. depressum type was 13.8 and 0.425 ton/ha. This difference was not significant at the 5% level. Soil carbon sequestration increased significantly in areas covered with studied species (t = - 6.902, p < /em> = 0.001), compared to the areas without any vegetation cover. The carbon conversion coefficient of above and underground organs of the studied plants was significant at the level of 5% and the carbon sequestration of aboveground parts of the plant to underground carbon sequestrated ratio in Z. fabago and L. depressum was 2.43 and 2.08, respectively. Considering the carbon storage capacity of plants studied (in the soil and plant), it can be concluded that these plants can play an important role in carbon sequestration at the least possible cost, and mitigation of climate change consequences in arid regions.

One of the most important features of the desert areas of Iran is the existence of windy sand dunes, which their dynamics and movement over time have distinguished them from many other geomorphological phenomena. The main objective of the present study is to evaluate the displacement of sand dunes in one of the largest sand complexes in the world, Rig Yalan in the east of the Loot desert. For this purpose, Sentinel-1 satellite images, which are considered SAR satellites, were used. In this regard, four Sentinel-1 satellite images were used at the beginning of summer 2017, 2018, 2019, and 2020. The offset tracking method was used to estimate the displacement of sand dunes in the study area. In the Offset Tracking method, the amount of horizontal displacements is measured by calculating the amount of deviation or correlation between two radar images taken from the same area. In this approach, the best match between the two images is achieved by maximizing the normalized cross-correlation. Based on the obtained results, during the study period, the amount of displacement of Yalan sand dunes in the closed and non-mobile areas has been up to a maximum of 3 meters per year in the large sand pyramids of the region, which are mainly concentrated in the center, west and south of the area. The movement of huts, ripple marks, longitudinal and transverse hills, and finally interconnected funnel-shaped sand pyramids of Yalan sand has not occurred in a fixed and definite direction and each part of it according to the morphological condition, the orientation of ridges as well as hill size and height different biases and displacements are observed. Based on the obtained results, all the features of the sand in Yalan sand are displaced on average about 0.94 meters per year.

Saravan is one of the most date-growing regions of Iran, and the Mazafati cultivar is a high-yielding cultivar of this region. Dust phenomenon in this city occurs in summer, coinciding with the productivity of palm trees. In this study, the effect of dust on the leaves and clusters of date trees and its yield in three regions of Saravan, Jalqh, and Rutak with different dust intensities were investigated in 2016 and 2017. Five groves were selected in each of the three areas, and within each grove, five palm trees were identified, and five leaves from each tree were selected randomly. Sampling was done during May, June, July, and August. The results showed the effect of dust intensity on the drying of leaves, leaflets, and fruit marketing. According to statistical analysis, the amount of dust in the study areas during two consecutive years had a significant and undeniable effect on the changes in the studied traits. The results of the average comparison of the total yield of dates showed that the Saravan region had the highest yield, about 210.14 kg per tree, and the Jalqh and Rutak areas, respectively, had 129.57 and 63.77 kg per tree. These results showed about a 30 to 40% reduction in yield of Mazafati cultivar dates in the Rothak region with the highest dust intensity. The results showed the destructive effects of dust on the studied traits.

One of the requirements for implementing natural resource governance and empowerment of rangeland users is the analysis of social relations in the social network of users. In this research, the analysis of the social network of rangeland users with an emphasis on the links of trust, participation, and consultation in rangeland management measures was compared with the calculation of macro-level indicators of the network in the three customary systems of Fasanqar, Parvand, and Malvand. Also, the complete network method (census) has been used, and in three customary systems, all rangeland users, including 100 people, have been considered a statistical population. The results show that among the users of the customary system, the amount of social capital, stability of relations, and network balance with a density of 50.8% on average and consultation between them with a rate of 43.8 and 40.5 for the two villages Malvand and Fasanqar are poorly institutionalized. Low social capital and low turnover of trust, participation and consultation between the users of these two villages are important challenges in creating a participatory management structure, and consequently, improving rangeland governance in these areas and the need to further strengthen social capital by increasing building trust in the network and creating the desire of users of all three customary systems to participate in rangeland activities to create success in rangeland governance. However, in the two villages of Malvand and Fasanqar, there is a need to further strengthen social relations and increase social capital compared to the Parvand village.

Soil pollution by petroleum hydrocarbon pollutants is one of the most important environmental problems in different parts of the world. In the oil-rich regions of the west of the country and recent years, the depreciation of the oil extraction and exploitation system has led to leakage and distribution of oil pollutants in the soil and biological resources of the region. This study aimed to investigate the potential use of native rangeland plants and the addition of bacteria, and the amount of appropriate fertilizer to reduce pollution of total petroleum hydrocarbons (TPHs) in the soil. The pot experiment was performed in the form of a factorial design with a completely randomized design (CRD) with four replications. Plant treatments included three native or compatible plants of Medicago sativa, Agropyron trichophorum, and Atriplex canescens and bacterial treatments included Bacillus pumilus (B1), Pseudomonas putida (B2), and the combined use of these two bacteria with fertilizer recommendation based on soil testing. Also, control treatment (no plant culture, no bacterial inoculation, and no fertilization) was applied. The results showed that Medicago sativa, with a 55.16% reduction in soil TPHs had better performance than other plants. Inoculation of B1 bacterium in interaction with Medicago sativa and Agropyron trichophorum by decomposing 56.19% of soil TPHs was more successful than B2. However, Atriplex canescens was more successful than B1 in interacting with B2 bacteria and decomposing 54.64% of soil TPHs. With full fertilizer recommendation, Medicago sativa and Atriplex canescens plants were most effective, with a 68.56% reduction in soil TPHs. In soil treatment without plant cultivation, B2 bacterium had the best performance along with fertilizer recommendation. Bacteria improve phytoremediation efficiency by improving metabolic activities and developing the root system, and ultimately increasing plant biomass. The results showed a significant effect of interaction between bacteria and plant type on plant shoot dry weight at the level of α = 0.01.