فصلنامه تحقیقات مرتع و بیابان ایران
سال بیست و ششم شماره 1 (پیاپی 74، بهار 1398)

The aim of this study was to assess the rangeland health of North Sabalan in three-elevation classes (less than 1500, 1500 to 2100, and 2100 to 2700 meters), which were the representative of rural, rural-nomad, and nomad rangelands, using the landscape function analysis (LFA) in Ardabil province. For sampling, three 50-meter transects were established in each elevation class according to the uniformity of the habitat and distribution of patches. Using the LFA framework, three characteristics including stability, infiltration and nutrient cycling of soil surface were determined using 11 indicators. Statistical analysis of data was conducted using the LFA method and instructions of Tongway and Hindley in Excel software. The soil stability index for vegetation life forms in the elevation class of 2100 to 2700 m was more than that of the other two elevation classes, with significant difference (P>0.05); however, there was no significant difference between the first and the second class .Comparison of the infiltration and nutrient cycling indices for vegetation life forms in the elevation class of 2100 to 2700 m was also more than those of the other two elevation classes with significant differences (P<0.05). The stability index in the third elevation class (72.35) and in the second class (48.75), the infiltration index in the third elevation class (73.31) and in the first elevation class (15.99), and the nutrient cycling index in the third elevation class (78.75) and in the first elevation class (10.12) had the highest and least values, respectively. Overall, the health condition of the third elevation class was better than the other two classes. By examining the functional characteristics of ecological patches, we can identify the vegetation indicators affecting rangeland health, and then conduct proper management to protect that ecosystem.

In order to investigate the relationship between the distribution of plant communities and environmental factors in Bidokht area, a physiognomic-floristic approach was used. The appropriate area of sampling plot and sample size were determined by the minimal area method and statistical approach, respectively. In each plot, the number of plant species and their canopy cover were determined and vegetation mapping was conducted. In each of the plant communities, six soil profiles were drilled and soil samples (composite) were taken from 0 to 100 cm depth. After transferring to the laboratory, parameters of soil texture, lime, pH, electrical conductivity, organic matter, sulfate, calcium, phosphorus, potassium and nitrogen were measured. Information layers were also provided for altitude, slope and aspect of the study area. In order to determine the factors influencing vegetation distribution, PCA-ORD software was used to analyze the principal components (PCA). The results showed that there was a relationship between the factors studied and distribution of vegetation (four rangeland types). The results of principal component analysis showed that the most important environmental characteristics affecting distribution of plant communities in the region were clay, sand, organic matter, electrical conductivity, and potassium (PCA first axis).

Dust pollution is one of the most important environmental challenges in recent years in the Middle East and Iran. It is important to monitor and control the quality of dust particles in a wider range using the methods that are more cost effective and less costly. The present study aims to use numerical detection and analysis to determine the resources of dusts and the route over Iran and Isfahan province in May 2013. In this research, HYSPLIT, NAAPS, COAMPS models and MODIS images were used. The detection of dust was determined based on the characteristics of the brightness temperature in the infrared thermal range of the Modis sensor and the temperature thresholds for distinguishing this event from desert lands and clouds. The HYSPLIT model was used to track the movement path of dust particles. Based on the results obtained from image processing and model output, North of Saudi Arabia and Southwest – Northeast direction are respectively the origin and main route of dust entry to Isfahan. The results of HYSPLIT model were compared with the results of the COAMPS and NAAPS models for the optical dust depth and surface dust concentration and the mass flow rate. The detection of the MODIS satellite images also acknowledges the creation of dust and moving it towards the center of Iran and the province of Isfahan.

Knowing the ecological characteristics of plants and consequently changes in forage production during the season of grazing for grazing management is essential. Therefore, understanding the annual and monthly production of different rangeland types is essential for efficient and effective forage management. Consequently, relationships between forage production and climatic variables should be considered. For this purpose, the annual forage production was measured in the research exclosure of Arshaq Site rangelands in Ardabil province during 2007-2010 by clipping and weighing method. The monthly rainfall in this period was calculated using Mashkin-Shahr synoptic station data and then the amount of cumulative rainfall in winter and spring of each year was calculated. Afterward, the relationship between production and winter and spring rainfall as well as rainfall of different months of winter and spring was studied separately. Statistical analysis was performed using SAS software. According to the results, the average forage production during four years was calculated of which 28.95% belonged to Artemisia fragrans, 26.35% to Kochia prostrate, 19.55% to Stipa hohenackeriana, 4.77% to Astragalus brachyodonuts and 20.38% to the other species. Analysis of variance showed that the production of species among years were significant (P<0.01). In terms of stability (interactions of year × month), Artemisia fragrans and Kochia prostrata were stable, with a high yield; however, Astragalus brachyodonuts and Stipa hohenackeriana were stable with a low yield.

The occurrence of below-zero temperatures in recent winters in Khuzestan province has caused the freezing of Prosopis juliflora trees. The aim of this study was to determine the sensitivity of this species to freezing under zero temperatures. In this study, a split split plot was used in a completely randomized design with six replications. In order to apply the treatments, the branches of elderly trees and two-year old seedlings were considered as main treatment; below-zero temperatures (-1-, -3, -5 and 7 ° C) as the first sub treatment; and different times (1, 2, 3 and 4 hours) as the second sub-treatment. The amount of electrolyte leakage from the membrane of leaf and stem cells was measured and, based on this, LT50 was calculated. The chlorophyll (II) fluorescence and photosynthesis efficiency of the leaves were measured as indicators for determining the damage to frost. The results showed that there was no significant difference for all traits between branches of the old trees and two-year-old seedlings. The percentage of electrolyte leakage from leaf and stem increased significantly with decreasing temperature. The LT50 occurred at -5 ° C after three hours. At -7 ° C, after the first hour, LT50 occurred in the leaves and after the third hour in the stems. After freezing stress, the Fv/Fm decreased significantly. After two hours at -1°C, Fv/Fm did not change significantly but in three hours Fv/Fm decreased from 0.64 (in control) to about 0.48. It reached to 0.15 after applying four hours at -7°C.

This study was conducted in two separated experiments in the National Salinity Research Center in 2016. In the first experiment, the effect of 12 priming treatments consisted of potassium nitrate, sodium chloride, calcium chloride, and GA3 with control were investigated on seed germination of Salicornia (Salicornia bigelovii var. LVYUAN no.1) in order to select the best priming for the second experiment. In the second experiment, the effects of different salinity levels (12.5, 25.0, 37.5 and 50.0 dS m-1) and GA3 concentrations including 500 and 1000 mg L-1 were also evaluated on seed germination of the Salicornia genotype. The salinity treatments were prepared by different percentage of Persian Gulf water. The results showed that all the priming treatments increased germination percentage compared to the control, and the highest effect belonged to the concentrations of 500 and 1000 mg l-1 of GA3,by 142.3% and 119.1%, respectively. It was revealed in the second experiment that salt stress significantly reduced percentage and rate of seed germination, so that salinity treatments as 12.5, 25.0, 37.5 and 50.0 dS m-1 could reduce germination percentage by 11.8%, 40.3%, 63.3% and germination rate by 81.4% and 21.3%, 40.0%, 62.3% and 70.1%, respectively. However, GA3 priming could improve the salt tolerance and compensate a part of this loss, especially at 500 mg L-1. Application of GA3 increased salt tolerance threshold of Salicornia at germination stage. In no prim and GA3-priming treatments at 500 and 1000 mg L-1, salinity tolerance thresholds were 4.15, 9.31 and 6.56 dS m-1 and the threshold of 50% reduction was 20.36, 35.97 and 31.39 dS m-1, respectively. In general, the results indicated that seed germination and rate of Salicornia were improved using GA3.

Considering the importance and basic role of participation and social cohesion of beneficiaries in the success of reclamation and improvement projects, the aim of this study was to investigate the effects of rangeland beneficiaries' social cohesion on their participation in reclamation and improvement activities in northeastern rangelands of Golestan province.
This research was descriptive-survey, conducted with stratified random sampling. Questionnaires were used for data collection. The validity of research was examined by using the views of natural resources and social sciences experts and its reliability was assessed according to the Cronbach's alpha coefficient for the main variables. The statistical population of the study consisted of 461 exploiters in two nomadic and rural exploitation systems (N = 461), among which 210 beneficiaries were interviewed using Morgan table. According to the results, the interaction section with an average of 3.75 and the conflict section with an average of 3.73 had the most and least impact on the social cohesion of the beneficiaries, respectively. The findings indicate that the beneficiaries have more contributed to reclamation practices as compared with rangeland improvement projects.Also, there was a positive and significant correlation between the social cohesion and the participation rate of beneficiaries in reclamation and improvement plans with a correlation coefficient of 0.474 at a confidence level of 99%. Nomadic beneficiaries had more social cohesion than rural beneficiaries.  Moreover, there was no significant difference in the participation rate in both nomadic and rural exploitation systems.Thus, the potential of local communities could be used in conducting range improvement and reclamation practices in areas where interaction and social cohesion are high.

This study was conducted in the rural allotments of arid and desert rangelands of Nodoushan, Yazd. Nine ecologically similar allotments were selected in the area and one herd was selected in each of the allotments.The study livestock were Nodoushan pure goats with an average number of 230 goats in each herd. The objective of this study was to determine the income, cost and benefits of the Nodoushan goat. The results showed that the highest present expenditures were related to the manual feeding of livestock and shepherd wages. The highest income was related to livestock, milk and yogurt sales, respectively. In all nine allotments, the costs were higher than the incomes, leading to a negative net income in each of the allotments. Valuation using present net value based on 15,18 and 20 percent discount rates in 2015,2016 and 2017 showed that net present value and benefit-cost ratio were less than zero and one, respectively, in all the three years. Thus, traditional animal husbandry in the study areas is not economically profitable.

Lack of proper business is one of the factors affecting the exploitation of natural resources and desertification. Low per capita income, low savings and lack of access to credit for poor people, especially for women, make it difficult to eliminate self-employment, productive jobs and income-generating businesses. In desert and arid areas, under such conditions, livelihoods are the only way to increase the pressure on ecosystems and unskilled exploitation. Microfinance for women without income is one of the possible ways of achieving sustainable economic and social development in these areas. The purpose of this study was to investigate the effects of credit microfinance funds on the empowerment of rural women as the weakest economic community in these areas. The research method was descriptive-analytic. A sample of 188 rural women members of the Southern Khorasan Mortgage Fund was considered. To ensure the validity of the questionnaire, the research committee examined and verified the various dimensions of the questionnaire. The reliability level of the questionnaire was obtained using Cronbach's alpha (0.952). Pearson correlation test, mean comparison, and ANOVA and POST HOC and LSD post hoc tests were used in statistical analysis in SPSS software environment. The results of this study showed that there was a meaningful relationship between the empowerment of rural women and age variables, the number of years of membership in welfare funds, educational level, loan adequacy, loan amount, monthly income and their environmental outlook, and the level of empowerment varied among rural women. The research findings showed that microfinance credits were able to improve the socio-economic status of local communities by attracting women's participation as permanent partners in desert management.

This study was implemented to prepare a model for soil salinity mapping using Landsat5 images in several provinces including Bushehr, Semnan, Fars, Kerman and Hormozgan. At the beginning, 50-100 samples from soil surface were taken and sent to the Laboratory. Then in order to evaluate and identify soil salinity, TM Landsat satellite images and statistical models combined with satellite`s spectral indices were used. After evaluating the accuracy of statistical models using test points, the best model for the study area was selected and the salinity maps were developed based on the regression model. The results showed a significant relationship between soil salinity and spectral index. In Fars province, NDSI salinity index had the highest correlation with soil electrical conductivity (0.35) with a regression coefficient of 66% and RMSE and MBE statistics of 2.58 and 0.66, respectively. In Kerman province, the tasseled cap three index had the highest correlation with soil electrical conductivity (0.47) with a regression method coefficient of 65%, and RMSE and MBE of 10.3 and 0.51, respectively. In Hormozgan province, the results showed high correlation with soil salinity indicators SI2 level of 72 percent. Stepwise method with R-square of 0.518 was selected for the Hormozgan province whre the RMSE and MBE were reported to be 2.5 and -0.35, respectively. Also in Semnan province, 5 and 7 bands of Landsat showed the highest correlation with soil electrical conductivity (respectively 0.65 and 0.75). By using stepwise regression, the linear relation with R-square of 0.6 was obtained, and RMSE and MBE values were reported to be 2.83 and -0.81, respectively.

Over the past few decades, there have been many global efforts to combating and mitigating desertification, and one of the most important actions is the United Nations Convention on the combating desertification. The present study aimed to assess the severity of desertification and identify the most important factors affecting land degradation in the Jazmurian basin. In this study, the IMDPA model was used to assess the desertification severity. Due to the time and cost limitations, two criteria for water and climate were selected. At first, by determining the geometric mean of the indices and then the criteria, the total desertification was calculated and the quantitative value of the indices and criteria and the final desertification were divided into four classes: low, moderate, severe and very severe. Then, using GIS, the desertification intensity map of the area was drawn up in the study periods. The results showed that in the study area, the water criterion was dominant and classified with a weighted mean of 3.2 in the sever class. Subsequently, the climate criterion with a weighted mean of 2.4 was in the next rank. The results indicated that the most important desertification indices in the study area were groundwater drop, electric conductivity of water, precipitation, TRANSO Drought Index, Drought Continuity Index and SPI index.

Jazmurian basin in the southeast of Iran is one of the most important and vital basins. Due to the lack of surface water resources and placing in the priority of use this basin is faced with a sharp decline in the level of underground aquifers.TheThe aim of this study was to identify the factors affecting groundwater resources and predict the groundwater level and its variation in Jazmourian Basin. In this study by considering the importance of identifying the factors affecting the condition of groundwater resources and the causes of decline, initially, the geological and geomorphological features of the basin and its impacts on the quantity and distribution of the groundwater resources were studied. Then, the effect of hydrological droughts with using two streamflow index (SDI) and the standardized precipitation index (SPI) at hydrometric, pluviometric, and synoptic stations located in the basin aquifers was studied. The portion of perceptions on changes in groundwater resources by wells, spring, and aqueducts, as well as the impact of surface structures and expenditures on land surface level changes were determined. In addition, the average monthly and annual mean of groundwater levels during the years 1370-93 were investigated using time series models to predict groundwater changes by the year 1420. The study results on the effect of different factors on groundwater water changes showed that hydroclimatic droughts, although affecting underground water changes, did not have a significant effect. The dams and deep and semi-deep wells with negative correlations of 0.83, 0.75 and 0.68 had the most negative effects on groundwater drops, respectively, and the average discharge of wells and springs increased significantly with increasing groundwater level. Also, the study of changes in groundwater level in the basin indicates a significant decrease (0.37 m / year) and predictions show that in the coming years it will face more severe losses. The high level of decline was observed in the summer with a change of 1.96% and in the autumn it was 1.78% lower than the other seasons. Overall, the results showed that if the current trend of exploitation of the groundwater resources continues, the region will be facing more challenges.

Managing the optimal use of water resources is one of the most important issues in sustainable development. Considering the importance of studying groundwater in the field of drinking, industry and agriculture, the study of water qualitative changes can be important for humankind. In this study, groundwater level depletion and electrical conductivity (EC) were used to investigate the quantitative and qualitative changes of groundwater in Karaj plain. The water level hydrographs were drown using Thiessen method based on the piezometric wells data and the groundwater depletion, the elevation contour line, and iso- electrical conductivity maps were provided using GIS. Quantitative changes were studied with reading of each well in different months in a 15-year period (2001-2016). The obtained results showed that the vast range of Karaj plain was depleted due to the lack of proper recharge as well as the over-exploration of groundwater. In addition, the relation between EC and anions and cations (such as Ca2+, Mg2+, K+, Cl-, Na+, SO42-, HCO3-) were determined. The calculated Standard Index of Annual Precipitation (SIAP) in five meteorological stations showed groundwater depletion due to rainfall reducing and drought. Electrical conductivity had direct relation with concentration of ions in all cases. According to the hydrographs, the average level of groundwater decreased to 1.02 m over 15 years and the groundwater level depletion consequently decreased the water quality.

The knowledge of livestock grazing behavior is one of the effective factors in rangeland management. This research was carried out in order to recognize the sheep grazing behavior in the rangelands of Cheshmeh Anjir, Fars province, during the years 2007-2010.The indicators assessed in this research included the daily distance traveled by livestock, average livestock movement, speed, and the time spent grazing. To determine these parameters, a GPS device was used and attached on the back of a 4- year old ewe using a special belt. Thus, after the start of grazing in the rangeland, the GPS was activated and then its data were extracted using mode track in ILWIS software at the end of the day. Data analysis was done in a completely randomized block design method using SAS software. The results of the study years showed that the average livestock movement speed and the daily distance traveled by livestock were significant at 1% and 5% levels, respectively; however, the time spent grazing did not show significant differences. Also, the results of study months showed that the average livestock movement speed was significant at 5% level and the daily distance traveled by livestock and the time spent grazing were not significant. According to the results, August 2008 with the mean value of 4 m/s and June 2009 with the mean value of 29 m/s had the lowest and highest average livestock movement speed, respectively; however, June 2009 with the mean value of 4.2 m/s and August 2008 with the mean value of 15.4 m/s had the lowest and highest distance traveled by livestock, respectively. The knowledge of mentioned factors will help rangeland management to determine the appropriate time for livestock moving and will increase livestock performance.

Over 50% of the country's surface is rangeland and livestock grazing is the main use of rangelands. Therefore, in the range of cities, rangelands should be considered not only in terms of livestock forage, but also for recreational aspects. The Gilizjand Watershed with an area of 16210.44 hectares is located in northern Firouzkooh city of Tehran province. According to the Demarton modified method, it has a cool semi-arid climate. This research was conducted on the basis of the FAO guidelines (1991), and GIS on a scale of 1: 20000, the limiting factor method was used. At first, the existing condition of the rangelands was studied. Then, factors affecting tourism including environmental and ecological factors (climate, elevation, slope, attractions of the area, water resources, and soil) and infrastructure factors (access to the area and distance to service centers and welfare centers) were studied. Eventually, the suitability of the rangelands of the region was determined for tourism and recreation.The results showed that 1% of the area was in the good suitability class (S1), 9.4% in the middle suitability class (S2), 29.4% in the poor suitability class (S3) and 60.2% in the non suitable class (N).The results also showed that the slope percentage, water content, distance from human-made attractions and plant composition were limiting factors for tourism in the Gilizjand watershed.

Estimation of the soil temperature in arid regions is one of the most important issues in planning the projects of desertification, water resource management, and establishment of vegetation.The present study aimed to compare the accuracy of artificial intelligence methods in order to estimate soil daily temperatures using meteorological data (daily minimum and maximum of temperatures, sunshine, and evaporation), as well as, identifying the most important factors on soil temperature in Zabol and Shiraz synoptic stations. For this purpose, soil daily temperature was estimated at 5, 10, 20, 30, 50 and 100 cm depths by using the three-year period data (2011-2014) and artificial neural network, neuro-fuzzy adaptive genetic programming, and combined neural network-genetic algorithm approaches. Thae results were evaluated using the root mean square error (RMSE) and mean absolute error (MAE) and determination coefficient. Based on the results, there was more dependence between the air temperature and soil temperature at the topsoil so that, the highest and the lowest correlation between actual and simulated data were observed at 5 cm (mean R2=0.92) and 100 cm depths (mean R2=0.56), respectively. The accuracy of the methods used was different from each other in estimating the soil daily temperature. Based on  results, in Zabol and Shiraz stations, combined neural networks - genetic algorithm approach and artificial neural network methods provided the most accurate estimation of soil daily temperature, respectively (the mean RMSE=3.69, 2.86 and mean MAE=3.23, 2.57 respectively). According to the results of the present study, it is suggested that in order to choose appropriate time and depth of seeding in the vegetation reclamation projects in arid regions, through considering of climatic conditions of each region, precise artificial intelligence techniques could be used to estimate the soil daily temperature.

In recent years, dust has had a significant impact on some of the morphological and physiological characteristics of plant species. In this study, the effect of simulated dust on morphological traits of Bromus tomentellus and Medicago sativa like plant height, SLA, aboveground and belowground biomass, root volume and length and physiological traits such as chlorophyll, gas exchange, and electrolyte leakage were studied. In B. tomentellus, dust caused to increased height; however, in M. sativa, dust had no significant effect on plant height. SLA and aboveground biomass were not influenced by dust in the study species. The below-ground biomass increased in M. sativa but no difference was observed between control and dust treatments in B. tomentellus. In M. sativa, the root volume and root length increased. In B. tomentellus, the root volume increased, but no significant difference was observed in root length. Dust had no significant effect on chlorophylls for both species; however, photosynthesis and stomatal conductance were reduced. Transpiration decreased in M. sativa but no significant effect was found for B. tomentellus. In general, dust, especially for legume species, limits physiological activity, and the study species become compatible with stress conditions through increasing the below-ground biomass.

Due to vast desert area in Iran, wind regime studies are important for the railway safe design as well as aeolian sediment transport. In this study wind regime and sand drift potential (DP) were calculated with Fryberger method in nine meteorological stations located near to the Qom –Tehran railway (178 km). For this reason, hourly wind speed and direction data were analyzed. Annual wind roses showed that West and Northwest winds were predominantly about 40%, 50%, 42% and 57% at the stations of Tehran, Shahriyar, Qom, and Imam Khomeini airport, respectively.  The highest amount of sand drift potential was at the Imam Airport station (DP= 574, UDI=0.8) in the west and its lowest value was at Qom station (DP= 109, UDI= 0.47) in the south of the region. The drift potential (DP) for aeolian deposits was generally high (DP >400) in the Garmsar (DP= 481), Salafchegan (DP= 485), Saveh (DP= 552) and Imam Khomini airport (DP=574) climatological stations. DP was relatively moderate (200>DP>400) at the Shariyar and Kahak stations in the northwest and south of study area, respectively; and weak (DP<200) in the Tehran and Qom climatological stations.  There was an increasing trend in the transport of sand when moving from Namakzar railway station to the Imam Khomeini railway station. Also field evaluations indicated the sensitivity of the Separ Rostam-Namakzar block to entry of sand, which was 21.3 kilometers long. Finally, it is suggested to railway directors of the Islamic Republic of Iran to proceed with the assessment of sand drift potential near railways station for control of sand deposition.

The calculation of the grazing capacity requires the consideration of factors affecting it. Due to the effective factors, the long-term grazing capacity model was designed, and then the capacity of the rangelands was calculated. Grazing capacity was calculated by the proposed model in four steps including estimating the average good production, calculation of available metabolic energy, the daily requirement of the animal unit and grazing capacity. Due to the drought condition of habitats and fluctuation of forage production in different years, one cannot calculate grazing capacity with once production measurement for the long-term. Hence, the average good production of habitats was determined and based on that, long-term grazing capacity was calculated. The average good production of Golestan Kouh, Vardast, and Pashmakan habitats in the statistical period of 6-7 years was estimated to be 425, 233.8 and 343.3 kg/ha, which are related to normal years in terms of rainfall. The grazing capacity of habitats in a quarterly period of four months was calculated to be 0.8, 0.3 and 0.5 animal unit per hectare so that if there is a drought for 12 consecutive months, there will be no damage to vegetation. Meanwhile, there is not much damage to the beneficiary and he will not have to sell too much of his livestock. The area needed for grazing of an animal unit in the rangelands was suggested to be 1.3, 3.3 and 2 hectare. This amount is recommended to be one hectare for a 30-year period based on a common method in range management plans. This indicates the need to pay attention to the factors affecting the grazing capacity and emphasizes the application of the proposed model in order to calculate the rangeland capacity.

Collection of appropriate quantitative data is necessary for proper management and planning in rangelands. One of the ways to access this information is choosing the appropriate methods of sampling and determining the appropriate length of transect for vegetation cover measurement. Therefore, this study was conducted in 2016 in Ariz rangelands located in the northwestern of Sanandaj city. For this purpose, transects with a length of 20, 50, 100, 150, 200, 300 and 400 meters, each with four replications were established perpendicular to slope and parallel to slope in the vegetation type of Bromus tomentellus - Festuca ovina. The 400-m transect was considered as a control for calculations. The obtained data from sampling were compared by ANOVA. The obtained results from different transect lengths were also compared by (E%) 2×T factor. The mean comparisons of vegetation cover percentage of transects were performed using t-student test. According to the results of this study, the transects of 20, 50, 100 and 150m length showed a significant difference with the control transect (400 m) in terms of accuracy index ((E%) 2 × T). However, there was no significant difference among the transects of 200, 300 and 400 meters length for the accuracy index. Therefore, the application of 200-meter transect is recommended regarding the cost and time.