فصلنامه تحقیقات مرتع و بیابان ایران
سال بیست و هشتم شماره 4 (پیاپی 85، زمستان 1400)

Biological stabilization of dunes is one way to prevent wind erosion and the creation of sandstorms. Clligonum is one of the plant species that due to its unique root structure can settle in the dunes and stabilize them. In this study, we intend to investigate the most suitable species and age of Calligonum shrub for planting in three different points of Kashan long sand. This research is in the form of split-plot (split plots) based on the randomized block design. Analysis of variance showed that the differences between different locations and the age of different seedlings and species of Calligonum were significant at the level of (p≤0.01). In all three age groups, Calligonum turkestanicum with 61.15% had the highest establishment, and C. comosum is in the second rank, and C. schizopterum and C. bungei species were in the third and fourth ranks, respectively. Siazgeh region, with an average of 59.7%, has the highest percentage of seedlings. Three-year seedlings, with an average of 58.7%, had no significant difference with two-year seedlings with an average of 57.01% and with one-year seedlings with an average of 53.84% at the level of (p≤0.01).Accordingly, the use of 0biennial C. turkestanicum seedlings and three-year C. comosum seedlings is recommended for sand stabilization in Kashan region.

Rangelands capacity depends on several factors, including the amount of forage production. Forage production varies during the grazing period and different years. The goal of determining grazing capacity is to estimate the forage production within the grazing period. This project was carried out over a period of 4 years (2006-2010) to determine forage production and consumption at different stages of growth. For this purpose, at the beginning of grazing season, the amount of forage remaining after grazing until the exit time of livestock was harvested at one-month intervals. Forage production was measured within the enclosed and adjacent area, and the amount of consumption of each species was determined. The collected data were analyzed based on a completely randomized design. The combined analysis of variance showed that production was significantly different (P<0.01) in years and months of the growing season. The highest amount of production was recorded in 2009 and the lowest in 2008. The ratio of forage produced in unfavorable to favorable years was 50%. In other words, forage production in 2009 was double that of 2008. This ratio was 13% to 79% among species. The peak of monthly rangeland production was in June and was the same for most species. The average rangelands production at the four-year study was about 650 kg/ha, and the contribution of three species Festuca ovina, Bromus tomentellus, and Tanacetum polycephalum were 24%, 20%, and 11%, respectively. The highest forage consumption was recorded in July and then in August. On average, about 71% of forage production was consumed during the grazing season. The lowest and the highest forage consumption was observed for Phlomis olivier  (37%) and Silene ampullata (100%), respectively.

(Festuca ovina) is one of the most important and palatable rangeland species in the rangelands of Mazandaran province and has a wide range of distribution in mountain rangelands that, in addition to nutritional value for livestock, plays a role in the breeding and rehabilitation program of mountain rangelands. Due to the importance of this species, several populations of F. ovina species, whose seeds were collected from different rangelands of the province, were planted in plastic trays. After germination and a short period of operation, in early spring, in the area of Poshtkuh research station in the southeastern heights of Sari, they were planted on two 20-meter-long lines so that 40 bases of each accession were placed on the planting line. Their spacing on rows of 50 m and line spacing of 1 m were considered. The experiment was conducted during 2011-2015. The evaluation began in the spring of 2013. Evaluation criteria for plant selection were phenological stages, plant height at the time of cluster emergence, canopy level, forage production, and seed production. Various phenological stages, including vegetative stage, flowering, seed formation, and fall regrowth, were recorded with weekly reference from the bases that have been nailed for this purpose. The obtained data were statistically analyzed in SPSS16. The results of the combined analysis of variance of the data related to the performance of the evaluated factors showed that there is a significant difference at the level of (p≤0.01) between the six populations of the studied species. The highest amount of canopy cover, plant height, viability, seed production, and forage production is related to the population of Siahsang rangeland, and the lowest values of the mentioned factors are related to the populations of Kangeloo and Doona rangelands. Therefore, to produce and strengthen forage vegetation, the seeds of this population can be used in the mountain rangelands of the central regions of Mazandaran province.

In the present study, we compared different sampling patterns and different plot dimensions to estimate the percentage of canopy cover and forage production in rangeland habitats around Choghakhor Wetland. The choice of sampling method was based on the opinion of the researcher. Sampling was performed in three different plant communities, in two patterns of six and three plots. Different dimensions of the plot (including 1×1, 1×2, 2×2, and 3×3 m2) were used as a nest to estimate the production and the percentage of canopy cover. Sampling was in each community within 30 sampling units along three transects. The canopy cover of the species was estimated by estimating and producing them by double sampling. Species density was calculated by counting bases in 2×2 plots. In each population, the type of distribution of dominant species was determined by statistical tests. The results showed that two different sampling patterns and four different plot dimensions have significant differences in estimating the percentage of cover and plant production (P≤0.01). According to the interaction of the community and the pattern, plot dimensions with pattern and plant community, patterns and plot dimensions with each other, there was no significant difference. The effect of plant community with plot dimensions on a cover percentage at (p≤0.05) and production at (p≤0.01) is significant. In Gundellia tournefortii-Couisinia Bakhtiari plant community with random distribution patterns, two different sampling patterns in 1×1 and 1×2 m2 plots were significantly different, and in other dimensions, no significant difference was observed. The two different sampling patterns in the Daphnea mucronata-Astragalus adsendence community with the uniform dispersion pattern were significantly different only in plot 1×1 (p≤0.05) and شdid not differ in other sizes. The mentioned patterns in the population of Melica persica-Agropyron trichophorum with the heap pattern distribution in statistical plots of 3×3 m2 did not show a statistical difference, but in other dimensions showed a significant difference (p≤0.05).

The main objective of the present study is to delineate all-natural resources of Iran with the priority of desert and semi-desert areas using indicators and criteria extracted from remote sensing data and new satellite image classification techniques. Accordingly, desert, semi-desert, and salinity areas of Iran in conjunction with other natural resources areas (such as forests, rangelands, water bodies, and farmlands) were studied using time-series MODIS satellite images and different indices and parameters such as Albedo, NDVI, and surface temperature during day and night along with the temperature difference between day and night. Here, unlike the classical classification methods, based on using one-single satellite image and features such as vegetation density or surface temperature, the behavior of different natural resources over time, extracted from satellite images, was analyzed. Accordingly, the temporal behavior of each of the mentioned natural resource areas during 2019 was studied and analyzed using the remote sensing criteria. The basic object classification method was used to classify the country using the mentioned indicators using the least distance technique based on fuzzy logic. Based on results, about 41.2%, 14.8%, and 3.9% of Iran (totally about 60% of Iran) are classified as desert, semi-desert, and salty areas, respectively. By considering the percentage of rocky mountainous areas (11.3%), about 71.2% of Iran has no biological conditions (unsuitable for agricultural activities). As expected, desert and semi-desert areas are concentrated in central, eastern, southeastern, and southern regions of Iran, and no signs of such areas are found in the northern, northwestern, and western of the country.

This study aimed to compare the effects of roots and leaves of Prosopis juliflora (SW) DC at different concentrations on emergence, vigor, radicle, and plumule length of two species of Taverniera spartea (Burm. F.) DC. and Pennisetum divisum (Forssk. Ex JF Gmel.) Henrard in Hormozgan province, Iran. After grounding the leaves and bark of Prosopis juliflora and mixing it with the soil of Prosopis juliflora habitat (0, 20, 40, 60, and 80 g of each organ per kg of soil), 15 seeds of Pennisetum divisum and Taverniera spartea species with four replications were cultivated in the soil, and the desired variables were recorded and analyzed using GLM statistical analysis. The results showed that vigor, radicle, and plumule length of Taverniera spartea species in soil associated with bark was 10.77, 3.47, and 3.63 cm, and in Pennisetum divisum species were 5.7, 4.36, and 4.15 cm that was higher than in the leaves. Also, seed vigor, plumule length in Taverniera spartea species, and seed vigor, radicle, and plumule length in Pennisetum divisum species had the lowest values in 8% treatment. The interaction effects of concentration×organ also showed that the leaf extraction had significant decreasing effects on seed vigor, plumule length in both species, and radicle length in Pennisetum divisum species. Also, the emergence percentage in Pennisetum divisum species (18.33%) was the highest in the control treatment. The results showed that Prosopis juliflora has inhibitory effects on rangeland species, so the selection of this species for afforestation in desert areas should be done more sensitively and the use of native species (Ziziphus spina christi, Prosopis cineraria, and Acacia oerfota) should be prioritized.

Ecosystems’ cultural services, like beauty services, play an important role in human social well-being. Understanding the potential of ecosystems is essential in providing this service for sustainable ecosystem management. This study aimed to determine the beauty value of summer rangelands in Kerman province. Hence, the beauty value of ten rangeland types was determined through flowering plants in 200 plots in flowering season. The beauty value was estimated using four indexes, including relative Simpson diversity and relative canopy cover of flowering plants, relative flowering period, and relative maximum number of flower colors. The analysis of variance showed that rangeland types are different in terms of beauty value, and Astragalus gossypinus-Artemisia aucheri rangeland type had the highest beauty value and is a pioneer region for conservation programs. Salsola brachiata- Artemisia sieberi rangeland had the lowest beauty value due to severe grazing and vegetation degradation. Plant types were most beautiful in spring, summer and fall, respectively. Correlation analysis showed that relative Simpson diversity and relative maximum number of flower colors had the highest correlation with beauty value. PCA also showed that beauty value was positively correlated with the attributes, including species diversity and abundance of forbs. The beauty value can be considered a good indicator of the ecological value of ecosystems that should be considered in sustainable development.

The development of the cultivation of medicinal plants in sloping lands based on public participation has an important role in improving land productivity, employment status, and livelihood of communities. The aim of this study was to investigate the barriers to the participation of local communities in the project of cultivation of medicinal plants in the sloping lands of Chehel Chay watershed in Minoodasht County. The research was descriptive and survey. The statistical population was 350 people from local communities living in the watershed. Using Krejcie and Morgan's table and random sampling method with assignment, 184 of them were selected as the research sample. The data collection tool was a questionnaire whose validity was confirmed by experts and its reliability was obtained by calculating Cronbach's alpha at the rates of 0.74, 0.79, and 0.89 for social, economic, and organizational barriers, respectively. Data were analyzed using SPSS19 software. The results of the Spearman test showed a positive and significant relationship between organizational barriers to participation with the variables of the number of years of employment in agriculture, hours of listening to the radio and watching TV during the day, and negative and significant relationship with variables of the number of respondents traveling to the city per month, the relationship between respondents and extension worker per month and the number of medicinal plants cultivated by respondents. Also, the results of the Friedman test showed the importance of organizational barriers in the non-participation of respondents in the project of cultivation of medicinal plants. It is recommended to pay attention to teaching the cultivation of medicinal plants to local communities, more communication, and interaction of extension workers with them, providing inputs and creating a suitable market for medicinal plants.

Drought is one of the most important natural disasters that threaten human societies. Various indices are employed for drought monitoring. The purpose of this study is to evaluate and monitor the drought phenomenon based on two indicators of standardized precipitation (SPI) and standardized precipitation-evapotranspiration (SPEI) in Hormozgan province. SPI index is calculated only based on precipitation data, and SPEI index is calculated based on precipitation data and evapotranspiration potential values Torrent White method) of drought. For this study, monthly precipitation data and average monthly temperature data of five synoptic stations of Bandar Abbas, Bandar Lengeh, Hajiabad, Minab, and Bandar Jask for a period of 30 years (1988-2017) were used. The results showed that although the values of SPI and SPEI index were correlated, SPEI index was more sensitive to drought and faster response to it and showed longer dry and wet periods. Comparison of SPI index values of different climate stations revealed no significant difference between their SPI values. It was also found that there was no considerable difference between SPEI index values for selected stations. Finally, the findings showed that the spatial distribution of the SPI index was more uniform compared to that of the SPEI index in Hormozgan province.

Cement factories are one of the sources of ecosystem contamination. The purpose of this study was to evaluate the capability of Gundelia tournefortii species in the absorption of cadmium, lead, and nickel elements in rangeland ecosystems around the Yasouj cement factory and changes in the concentration of heavy metals with from the factory. For sampling plant and soil, distances 0 to 500, 500 to 1000, and 1000 to 1500 meters were selected, and in each range, five plant samples with root and five soil samples were gathered from the root depth of G. tournefortii. Indicators of Translocation Factor (TF), Bio Concentration Factor (BCF), and Biological Accumulation Coefficient (BAC) were used to evaluate the ability of G. tournefortii species. Results showed that the TF value of G. tournefortii species for heavy metals, nickel, and cadmium is larger than one. Therefore, G. tournefortii species can absorb and extract lead metals, nickel, and cadmium from phytoextraction. Results of the study of lead, nickel, and soil cadmium in the studied range showed a significant difference between the concentration of lead, nickel, and cadmium metals in three rangelands (P <0.01). With the distance from the factory, the concentration of soil studied was decreased. Results showed that the average concentration of lead, nickel, and cadmium is less than the maximum allowable amount in the soil. Generally, considering that the concentration of heavy metals in the ecosystem is increasing and adds to the contaminated land, the use of native plant species to absorb heavy metals from the environment and reduce pollutants can be effective.

Assessment of the potential ecological and natural capacity of each area with proper planning can lead to sustainable and continuous utilization of natural areas. By increasing the population and psychological pressures resulting from the bustle of cities, ecotourism has become doubly important as one of the ways to reduce the pressures on people. The development of ecotourism to conserve natural resources should be commensurate with the natural and social potential of the region. Due to the importance of conserving natural resources, the purpose of this study is to evaluate the ecotourism potential of Chaharbagh summer rangelands in Golestan province based on the FAO limiting method and using GIS. The factors assessed include two ecological categories (climate, altitude, slope, soil, water resources, distance to attraction places, value attractive vegetation) and infrastructure (distance to city, amenities, roads, and access routes). The results showed that the total area of the region is 25.36% (2249.29 ha) with medium potential and competence (S2), 28.65% (2542 ha) with low potential and competence (S3), and 45.98% (4079) hectare lacks ecotourism competence and potential (N). The results also showed that water resources, soil, slope percentage, vegetation attraction value, access routes, and distance to attractions are factors that reduce the potential and merit of tourism and altitude factors, distance to city and facilities, welfare as well as climate (temperature) are factors that increase the potential and merit of tourism. Chaharbagh rangelands have suitable facilities and potentials in terms of tourism, and observing the principles of tourism and preserving natural resources, in addition to creating employment and income for the residents of the region, can help the protection and sustainable development of the region.

Astragalus spp. are valuable in forage production, soil protection, etc. To evaluate the establishment and growth of herbaceous milkvetch, 10 genotypes, belonging to five species, including Astragalus vegetus. As.brevidens, As. brachyodontus, As. effusus and As. Cyclophyllus, were studied in Sanandaj in a randomized complete block design with three replications. Seed sowing was done in November 2018, and traits of plant establishment percentage, vigor, height and diameter of plant crown, number of branches per plant, average fresh and dry weight of the plant, and the ratio of dry to wet weight of the plant in 2019 and 2020 years was measured. According to the combined analysis of variance, the effects of genotype and year for all studied traits and the interaction of year × genotype were significant (p≤0.01) except for the percentage of establishment and the plant vigor for other traits. Results showed that seed germination, probably caused by seed dormancy or a stress tolerance mechanism, was gradual. In 2020, the mean of plant establishment was about 37%, the number of primary branches was 7.3, plant height and crown diameters were 35.2 and 35.9 cm, respectively, plant fresh and dry weight were 68.2 and 39.1g, and the dry to fresh weight ratio was 0.58. Results of principal component analysis (PCA) showed that two main components (PC1 and PC2) determined 80% of total variance and genotypes with high forage yield located in the third zone of bi-plot with a negative value of PC1 and mainly positive for PC2. In addition, the accession of As. effusus (West Azerbaijan) and three accessions of As. vegetus (Qazvin, Kurdistan and West Azerbaijan) in terms of adaptation and forage production are introduced as high forage yield and adaptable ones for rehabilitation of rangelands in Kurdistan and similar areas in the country.

Due to the prevailing arid and semi-arid climate, Iran has always suffered from the production and spread of airborne substances, especially dust. This phenomenon is very destructive due to its direct impact on the environment and human health. Therefore, this study aimed to investigate the variation trend of aerosol optical depth (AOD), normalized difference vegetation index (NDVI), rainfall, temperature, wind speed, and correlation between AOD and climatic parameters in Iran. Data on AOD and NDVI were collected from Modis sensor images and other data from the ECMWF climate site over 2000-2019 with a spatial resolution of 10 km. The Mann-Kendall trend analysis was used to investigate the trend of changes in these parameters, and the linear correlation model was used to check the correlation between AOD and climatic data. The results of the variations trend of AOD, NDVI, and climate data showed that the trend of these parameters was different in different regions of Iran so that NDVI and rainfall had decreased by 85.13% and 67.57%, respectively, while AOD, wind speed, and the temperature had increased by 71.43%, 71.86%, and 99.37% across the country, respectively. The correlation of AOD, NDVI, rainfall, temperature and wind speed revealed that AOD had a negative correlation with NDVI and rainfall in 50.94% and 51.31% of the country, respectively, while its correlation was positive with temperature and wind speed over 68.42% and 50.36% of the country, respectively. Therefore, the increase in airborne suspended particles strongly depends on the trend of variations in vegetation cover and climatic factors, including rainfall, temperature, and wind speed, which can be well studied using satellite and climatic data with appropriate spatial and temporal resolution.

Participatory management in the protection of desert ecosystems is important due to the high sensitivity and fragility of these ecosystems. However, insufficient attention to the position of stakeholders in the social relations network has led to its failure. Therefore, identifying key actors is significant in the participatory management of the desert ecosystems. This study was conducted to investigate the coherence of the cooperation network and determine the key actors of government stakeholders at both levels of government and public institutions considering the participatory management approach. Information and data were collected through surveying, interviews, and participating meetings with representatives of the organizations and local communities. After identifying 45 beneficiary government institutions, a social network analysis questionnaire was developed and completed by 41 members of the local community and 34 members of the governmental institutions. Then, the prepared data were entered into the Microsoft Excel software and were analyzed using the UCINET6.718 software. Two one-dimensional matrices of organization-organization and people-organization were used to delineate the networks; then, different macro and micro indicators of the network such as density, shear points, degree centrality, and betweenness centrality were calculated to interpret the networks. The results showed that density index in both organization-organization (0.672) and people-organization (0.77) cooperation networks were evaluated more than average. So, it is acceptable. Also, the Department of Environmental Protection of Qeshm city has the highest index of betweenness centrality among 45 identified devices in both cooperation networks. Therefore, more cooperation of the organizations involved in participatory management of natural resources is suggested to protect and develop the mangrove forests to reduce each type of environmental pollution.

Rangeland's development will not be possible without the participation of Ranchers. Today, network social capital can control the participatory behavior of users in the protection of rangelands and their customary boundaries. The purpose of this study is to analyze the social capital of the network among ranchers with different levels of participation in conservation projects (biological projects including seeding and enclosure; and biomechanics or banking projects) of the customary rangelands of Dehgolan city. The research method is descriptive-analytical based on a questionnaire, and its statistical population includes 275 users of rangelands in 10 conventional areas of the region based on the audit list. The samples were selected randomly, and 160 rangeland operators were selected using Cochran's formula. To determine the validity of the questionnaire, a panel of experts was used, which included professors and technical experts of the General Administration of Kurdistan Province. Cronbach's alpha values for "common goals of rangers with local networks" and "common goals of rangers with government networks" were calculated as 0.80 and 0.82, respectively. The results of the Helmert contrast approach showed that beneficiaries who were permanently involved in rangeland conservation projects had more common goals with local and government networks than beneficiaries who were temporarily involved in rangeland conservation projects. The results showed that using the social capital capacity of the network can change the participatory approach of users to implement rangeland conservation projects by strengthening the cohesion of local communities.