IRANIAN JOURNAL OF RANGE AND DESERT RESEARCH
Year:2018 | Volume:25 | Issue:2 (71) |Papers Count:23

The aim of this study was to investigate the effect of environmental factors on Prangos ferulacea Lindl. and P. pabularia Lindl. distribution in the rangelands of Ardabil province. Seven habitats of Prangos genus were identified, so that P. ferulacea was distributed in three habitats and P. papularia in two habitats. In each habitat, sampling sites were identified and in each site three transects of 100m were established, and the density of the study species were recorded in ten plots of 4m2. Soil samples were taken from the depth of 0 to 30 cm at the start, middle and end of each transect. In the vicinity of each habitat, sampling was done in the same way. In sampling plots, elevation, slope, aspect, and soil characteristics such as organic matter, N, P, K, pH, EC, and texture were measured. To investigate the effects of environmental factors on the presence or absence of the study species and to compare the characteristics of the variables measured one-way ANOVA and Tukey test were used. Discriminant analysis was used to determine the degree of importance of the environmental variables measured in the distribution of the study species. Results showed that P. pabularia was distributed in the habitats with the high content of P, clay, EC, rainfall, sand, slope and pH; while P. ferulacea was distributed where the elevation was high but rainfall and the content of K were low. According to the results of discriminant analysis, variables such as EC, organic matter, K, elevation, slope, aspect, silt, clay, rainfall, and temperature were effective in discrimination of sites and species distribution. The results of the present study could be useful to propose the species for range management, improvement and reclamation.

Remote sensing is the main technology to assess the expansion and rate of land cover changes. Knowledge of these changes in different parts has particular importance as the base information for different planning. The aim of the present study was the comparison of the maximum likelihood and fuzzy Artmap methods to prepare land use map using Landsat satellite images. In this study, changes in land cover were evaluated over the past 24 years in Omidiyeh. Sensor images of TM Landsat 4, ETM+ Landsat 7 and OLI Landsat 8 for the years 1990, 2000 and 2014, respectively, and topographic and land cover maps of the area also were used. Images of all three periods were classified into four land uses including rangelands, agriculture, saline lands, and residential areas. The overall accuracy of the classification results showed that the fuzzy classification method with a kappa coefficient of 93% had more accuracy in comparison with the maximum likelihood algorithm with a kappa coefficient of 81%. According to the obtained results, the most dynamic land use in the region was the agricultural area, whose extent increased from 1990 to 2014, and 32703. 32 hectares (32. 2%) was added to this land use. An increasing trend was also obtained for the residential land use with an area about 1325. 1 hectares (0. 94%). On the other hand, rangelands (13. 4% of the study area) showed the highest reduction in area (18857. 63 hectares).

Environmental crises and loss of natural resources are among the main causes of the establishment of environmental management systems. The optimal management of natural resources requires the assessment and classification of environmental and ecological potentials. Sand arrow is one of the most important accumulations landforms in Njarabad Erg in the northeastern of Toroud village. In this research, the morphometric and morphological parameters of the sand arrows and increase of their volume in the one-year period were measured. Then, using the regression analysis method, the type, and intensity of the relationship between the amount of increase in the volume of the sand arrow and the morphometric and morphological parameters of the sand arrows were investigated and the models were presented to estimate the sand volume. Morphometric parameters include the length and maximum width of the sand arrow and morphological parameters include height, canopy diameter and crown diameter of the plant. These models can easily calculate the volume of sand arrows in the study area. The results indicate that the relationship between the amount of volume increase and the morphometric and morphological parameters of the sand arrows follows the linear, power and exponential functions. The results show the maximum linear correlation between the volume of the sand arrows with canopy diameter with the highest R2 (0. 807) and the lowest Std error of the estimation (0. 13). The results of this study, primarily inform environmental managers about the state of the sand arrows system and secondly, as a tool for serving environmental managers, express the trend and extent of the landscape of the sand arrows in different time periods.

In this study, the potential of rangeland species Astragalus globiflorus and Acantholimon hohenackeri in heavy metals absorption including cadmium, lead, copper, zinc, and chromium was investigated around the Firoozkouh cement factory. Soil and vegetation sampling was performed at distances of 500, 1500, and 2500 meters from the center of the factory. Astragalus globiflorus and Acantholimon hohenackeri with three replications were examined in a completely randomized block design. In this experiment, samples were determined using the acidic digestion method using atomic absorption device. The results indicated that, as the distance from the factory increased, the concentration of cadmium and zinc in Astragalus globiflorus and Acantholimon hohenackeri showed an increasing trend, contrary to the concentration of lead. In addition, a decreasing trend was observed for chromium concentration in Acantholimon hohenackeri. The results of mean comparison showed that the concentration of copper, lead and zinc in Astragalus globiflorus, and the concentration of cadmium and lead in Acantholimon hohenackeri were higher in leaves as compared with roots. According to the results, there was a significant relationship between Astragalus globiflorus and copper, cadmium, lead and chromium, and between Acantholimon hohenackeri and copper, zinc and lead (P <0. 05). It can be concluded that the proximity to the factory was the most important factor for the accumulation of lead and chromium in the species studied. In this regard, it is suggested that the above species be used to remediate these elements from contaminated soil. It is also recommended that appropriate measures be taken regarding the use of these species by livestock around the factory.

This study was carried out in the Serizi-Bafq flood water spreading area of Yazd province. Vegetation sampling was performed in four flood spreading areas and the adjoining area as control in a completely randomized design. In order to investigate the vegetation changes, the transect-quadratic method was used and three transects with a length of 100 meters were established. On each transect, 10 plots of 5×5(m2) were used. Collectively, 120 plots were installed inside the flood spreading area as well as in the control area. The parameters of canopy cover, density and presence of the plants in the flood and control areas were measured. The data were analyzed using t-test in SPSS software. The results showed that the percentage of canopy cover, density and presence of Hammada salicornia, Seidlitzia rosmarinus as well as the percentage of total canopy, total density and total species presence showed a significant difference at the 1% level. A significant difference was also found for litter coverage at the 5% level. The total percentage of annuals, Zygophyllum europterum, Salsola yazdiana, and Artemisia seiberi in the flood and control areas was not statistically significant. Flood water spreading operations have led to the presence of Zygophyllum europterum, Salsola yazdiana, and Artemisia seiberi. The vegetation percentage of these species is low in the current situation, but with repeated water logging in the flood spreading area, there may be significant changes in the long-term vegetation composition.

The study was performed with the aim of modeling the distribution habitats of Eshtehard rangelands using Maximum Entropy Method and determining the factors affecting each habitat. Vegetation and environmental data including soil characteristics and topography were collected. The initial map was prepared based on slope, elevation and direction maps and satellite images. At each site, three transects with a length of 750 m were established, two transects along the most important environmental gradients and one transect perpendicular to them. A number of 45 plots along each transect was placed at a distance of 50 meters. The size of plot sampling was determined to be two square meters according to the type and distribution of plant species with minimal area method. Soil profiles were dug at the beginning and end of each transect. Sampling was done from the depths of 0-20 cm and 20-80 cm. The list of species and the percentage of vegetation in each plot were determined. For each sampling unit, the latitude and longitude data, slope, direction, and elevation were also determined. Then the desired characteristics were measured in the laboratory. GIS and Geostatistics methods were used to map the environmental variables. The species distribution models were produced using the species presence data and Maximum Entropy Method (Maxent). The Kappa coefficient index and the area under the curve (AUC) were used to evaluate the accuracy of the distribution maps. The agreements of actual and predicted maps for Pteropyrum olivieri was well (K=0/7) and it was acceptable for Halocnemum strobilaceum, Salsola richteri-Artemisia sieberi, Artemisia sieberi, Artemisia sieberi– Stipa barbata (K=0/66, 0/64, 0/57, 0/66).

This research was conducted to evaluate the potential of different rangeland planting practices for carbon sequestration in various climatic and geographical regions of the country. For this purpose, the key sites of rangeland planting practices were selected in the Lorestan, Fars, Kermanshah, Khorasan Razavi, Mazandaran, Kordestan, Kerman, Markazi, and Esfahan. Then, the characteristics of the sites selected were recorded and sampling of soil, aerial biomass, and root was performed in a random-systematic manner. The results showed that rangeland planting practices in the semi-arid forests of central Zagros slopes had the highest carbon sequestration capacity. The seeding and pit-seeding of perennial legumes and grasses such as festuca, alfalfa, sainfoin and onobrichis could sequester up to 17. 4 to 80 tons of carbon per hectare. The contribution of soil in carbon sequestration was at least 93 percent of the total carbon stock of the study area. Rangeland planting practices together with exclosure caused to increased carbon sequestration up to two times. In these areas, pit-seeding was more successful than the other practices. In the Hyrcanian regions, the seeding of perennial legumes and grasses could sequester 18 tons carbon, ranked second after range planting practices in the central Zagros slopes. Rangeland planting practices in arid and semi-arid areas of the central and the eastern part of the country showed little effect on increasing the carbon sequestration capacity compared to other areas mentioned above. The highest carbon sequestration was recorded to be 5. 63 and 6. 51 tons carbon per hectare for the exclosure rangelands in Kardeh and Shamsabad watershed, respectively. Land use change from dry farming to rangeland in Kardeh watershed resulted in carbon sequestration of 4. 7 tons per hectare.

Land salinization is a major and destructive problem in the agricultural sector, which must be controlled by proper scientific management. The first step in this way is to identify and map the saline areas. Over the past few decades, the use of geostatistics and remote sensing techniques has been developed to map the soil salinity and monitor its changes. The purpose of this study was to compare the capability of different geostatistics methods to prepare soil surface salinity maps in a part of the Meyami plain, Semnan province. To do this, 225 soil samples were taken from a depth of 0-30 cm of soil from the intersection of regular grid lines of 600 * 600 meters using GPS. EC, pH and clay of soil samples were measured. The results showed that the Kriging method with an average absolute error of 2. 29 was more accurate than other interpolation methods and, vice versa, the Spline Thin plate method with an average absolute error of 4. 38 had the lowest accuracy. According to the map prepared, the highest, lowest and mean salinity in the Meyami plain were recorded to be 15. 69 ds/m, 2. 12 ds/m, and, 5. 24 ds/m, respectively.

A large surface area of rangelands in Iran is degraded due to some different factors such as overgrazing, climate-change and so forth. Therefore, an important part of rangelands species is endangered. Rangeland improvement and rehabilitation as well as introducing tolerant species are of utmost importance towards rangeland sustainability. For this, the seeds of different accessions of most important perennial shrubs were collected from the rangelands in Kerman province and cultivated in the research station of Kerman province. A study was conducted in a randomized complete block design with three replications under field conditions, to comparing the germination and establishment of the accessions. Data analysis was performed using SAS software and mean comparisons were made by Duncan's multiple range test. According to the results, Fortuynia bungei showed a better germination and establishment rate as compared with other species. In addition, among the accessions, the highest establishment percentage was recorded for Kouhpayeh (53. 03%) and Bam (52%) populations.

In this study, the relationship between different levels of trust including basic trust, interpersonal trust, institutional trust, and generalized trust with the participation of rangeland beneficiaries in rangeland rehabilitation and reclamation projects was investigated. The survey instrument was a questionnaire. The statistical population included all rangeland beneficiaries (78 people) in Choghakadoo, Sarpolzohab. The sample size was determined to be 67 people using Cochran's formula. Stratified random sampling was used to select the samples and SPSS20 software was used to analyze the data. The results of this study showed that there was a positive and significant correlation between different levels of trust with the participation rate of rangeland beneficiaries in rangeland improvement and reclamation and the correlation between the generalized trust and the participation of rangeland beneficiaries was stronger. Furthermore, in this study, 34 indices of different levels of trust were reduced to 12 factors by the factor analysis method, totally explaining 36/71% of variation in dependent variable (participation in rangeland improvement and reclamation. Generalized trust could be named as the first and most influential factor in this method. Therefore, considering the effect of different levels of trust in the participation of rangeland beneficiaries, it can be stated that the increased generalized trust, which is one of the dimensions of outgroup social capital, will result in increased efficiency of the participation of rangeland beneficiaries in range improvement and reclamation as compared with other levels of trust.

The aim of this study was to investigate the temporal and spatial changes trend of groundwater quality for drinking purposes in Jiroft plain. The role of land use and geological formations in the groundwater quality was also investigated. In this study, the parameters of electrical conductivity, sodium adsorption ratio, pH, calcium, chlorine, magnesium, sodium, and sulfate were used and the zoning of qualitative data was done by the geostatistical method of Kriging in ArcGIS9. 3 software; then, the classification of the region was done using Schoeller diagram. Results showed that in 2001, southern parts of the study area had a lower quality of groundwater but in 2014, northern parts had a lower quality. According to the results, the groundwater quality decreased overtime and the decreasing trend spread from the south to the center and the north of the region. Also, the land use map showed a low quality of groundwater in agricultural lands. The geology map showed a low quality of groundwater in central and southern parts. In general, it can be concluded that the water quality of the study area for drinking is decreased over time and influenced by land use and geological formations; thus, to improve the quality of groundwater resources the role of human factors (land use and agricultural activities) need be taken into account.

Changes in temporal and spatial patterns of droughts are always a pivotal element of water resource planning, and the necessary strategies for policy-making and integrated water resources management are considered based on this parameter. Drought is a phenomenon degrading the lands and sometimes causes irreparable damages. In this research, SPI and GRI indices were used to study the spatial and temporal patterns of meteorological and hydrological droughts in Bam Plain. The results of this study showed that the most severe meteorological drought and the most severe wet occurred in 2002 and 2014 in the study area, respectively. Also, the most severe hydrological wet (SHW) and the most severe hydrological drought (SHD) are related to 2002 and 2014, respectively. Meanwhile, the hydrological drought temporal pattern occurs with a one-year delay as compared with meteorological drought in the study area. According to the results of the spatial pattern analysis, the moderate and normal drought classes covered most of the region. In addition, as moving from east to west, the severity of drought is increased and wet periods are mostly observed in the northeast of the region.

Social capital is a prerequisite of co-management and local sustainable development. Present study makes an attempt to evaluate bonding social capital pre and post RFLDL project implementation in Deh-e-Reza village in Reagan County of Kerman province. Statistical population of this study consists of rural development groups’ members totaling 133 persons in 9 groups. The level of trust and collaboration ties of the beneficiaries’ network were examined through network analysis questionnaires, direct observation, and an interview with all beneficiaries based on network indicators including density, reciprocity, transitivity, and average Geodesic distance both prior to and post RFLDL project implementation. It was found out that the level of trust, collaboration, and social capital was moderate pre project implementation but there was an increase in these components following project implementation. Trust and collaboration exchange speed as well enhanced following project implementation and solidarity and unity increased on the whole. Last but not least, it can be claimed that implementation of this project boosted bonding social capital and co-management was established in the region.

Modeling the growth stages of plant species and its relation with environmental factors, especially climatic and edaphic changes, can lead to appropriate management and conservation plans for rangeland rehabilitation and improvement. The objectives of this study were to evaluate the AquaCrop model for two species (Medicago polymorpha L., Hordeum murinum subsp. glaucum (Staud. )Tzvelev) in the Shimbar protected area. Therefore, model evaluation was performed based on the data recorded during 2013-2015. Coefficient of determination (R2), absolute and normalized root mean square error (RMSE, NRMSE), Willmott agreement index (d) and Efficiency Coefficient (EF) were used to compare the simulated data with the data of the second year. The evaluation of AquaCrop model for canopy cover and biomass in selected species demonstrated that the model had the necessary efficiency for simulation. The values of R2, EF, and, d recorded for the canopy cover and biomass of Medicago polymorpha and Hordeum murinum subsp. glaucum were near 1. The values of RMSE calculated for canopy cover and biomass were between 1 to 3. 7 and 0. 03 to 0. 23, respectively.

Data gathering was done using 405 respondents from nomads and also 45 respondents from well-skilled and knowledgeable experts regarding migration and livestock grazing management in Fars and Bushehr provinces with the aim of identification and analyzing the most important factors affecting early and well-timed migration toward summer rangelands in Qashqai nomad (Shesh-Bolooki tribe) ecosystem in 2015. Descriptive and analytic methodology was applied using questionnaire and interview methods. In this study, the views of two respondent groups were assessed using Likert scale (five ordered response levels). Then, they were compared through parametric and non-parametric tests including analysis of variance, Mann– Whitney U and Kruskal– Wallis tests. The results showed that there was a significant difference between experts and beneficiaries views with regard to the priority of factors (P<0. 01). Based on experts’ views, the lack of enough forage in winter rangelands, early warm weather in winter rangelands, decreasing of precipitation and consecutive droughts, not having grazing license in winter rangelands and degradation of migration route were the most important factors affecting early migration. However, according to the beneficiaries’ views, reduced precipitation and consecutive droughts, not-having grazing license for winter rangelands, lack of enough forage in winter rangelands, lack of health facilities and services on the way from winter rangelands to summer rangelands and competing to reach summer rangelands among the beneficiaries, were introduced as the most important factors affecting early migration. Based upon the experts views, determining migration time by the government in coordination with beneficiaries, establishment of temporary settlements on the way between summer and winter rangelands, controlling the Stipa capensis species in winter rangelands through rangeland improvement plans, assigning rangers for summer rangelands and government support through providing supplementary forage were among the most important factors affecting well timed migration. According to the beneficiaries’ views, existing of suitable forage in winter rangelands, government support through supplementary forage provision, lack of competition between beneficiaries on reaching and exploiting summer rangelands, existing of enough forage in winter rangelands and having enough drinking water in winter rangelands rangelands In this research, it was found that there is a significant correlation between experts views (P<0. 01); however, no significant correlation was found between the beneficiaries views.

Livestock grazing is the most common type of rangeland uses that can affect the composition of rangeland vegetation, net primary production, stem to root ratio, and nutrient cycle. This research was conducted to study the impacts of various grazing intensities on nutrient allocation of phosphorus, calcium, sodium, and potassium in aerial and underground biomass of Artemisia aucheri in the summer rangelands on the southeast slope of the Sabalan. In this study, a systematic-random sampling was employed. Three parallel transects of 200 m length were established in each grazing intensity. Then along each transect, one square meter plots with 50 m intervals were established to collect the aerial and underground biomass. Analysis of variance revealed that the allocation of phosphorus and calcium of the aerial organs were significantly affected by different grazing intensities. In addition, sodium and calcium of underground organs were significantly different at 1% level. The results of this research and the effect of different grazing intensities on nutrient allocation could be used in the identification and management of livestock grazing and rangelands.

This study aimed to determine the most important ecological factors affecting the canopy cover of Astragalus gossypinus in some parts of semi-steppe rangelands of the Kurdistan province. Field survey was carried out in three areas of Kurdistan meadows including Dezli, Narran, and Murvarid saddle. The number of plots, according to the characteristics of the vegetation and other environmental factors, was calculated to be 6 for Dezli, 3 for Naran, and 4 for Murvarid saddle. The plots of vegetation were sampled in a random-systematic manner in an area of 1 × 1 m and along two transects of 100 m. Soil sampling in each plot was performed with three replications and at the depth of 0 to 50 cm at and between the base of the plants. Factors such as soil, clay, silt, sand, gypsum, lime, electrical conductivity, pH, phosphorus, calcium, magnesium, stones and pebbles, nitrogen, carbon, and potassium were measured. For the analysis of soil and vegetation, ANOVA, and in order to determine the effect of different environmental factors on the vegetation cover, multiple regressions were applied. To determine the most important factors affecting the canopy cover of vegetation, principal component analysis was also used. The results showed that the factors including carbon, potassium, pH, magnesium, phosphorus, calcium, lime, nitrogen, clay, sand, average annual rainfall, and the canopy cover percentage were significantly different at the level of 1%; while, the factors such as gypsum and electrical conductivity were not significant among the different habitats. The regression results showed that the factors including lime, height, and precipitation justified the changes of cover 25%, 12% and 7%, respectively.

Undoubtedly, one of the most important and impressionable societies to climate changes are nomadic societies and indigenous knowledge has pervasive roles in range and livestock management. For this purpose, perception and knowledge of the pastoral nomads to climate change were determined in summer rangelands of Semirom. The study population included the nomads of summer rangelands in Semirom. A total of 7700 nomads from different tribes of Qashqaei including Dareshoori, Amale, Shesh bolooki, and Farsimadan use summer rangeland of Semirom. To evaluate the indigenous knowledge and adaptation of nomads to climate changes, several methods were used such as depth and group interviews and questionnaires. The effects of age, sex, education, and range elevation were analyzed using Mann-Whitney test. The nomads believe that changes in temperature, precipitation, and wind are the main signs of climate change, as over 90 percent of nomads believe to precipitation decrease, increasing temperature, and wind speed. The most of the questions are influenced by age, sex, education, and range elevation. The questionnaires refer to adaptations such as delay time of migration, construction of block houses and pools, reducing livestock, feeding livestock with other forage resources etc. Our results showed that nomads of Qashqaei tribes acquired a perception about climate change during living in the nature.

The present study was carried out to investigate the effects of various improvement practices on ecological indicators of rangeland health using LFA method in Behbahan Chahshirin rangelands. To this end, three improvement sites including mesquite (Prosopis juliflora) tree planting, construction of contour furrow, and eucalyptus (Eucalyptus camaldulensis Dehnh) tree planting, implemented in 2000, were selected along with three control areas. For sampling in each site and based on climate, vegetation type, and vegetation changes, three transects of 100 m length and a distance of 50 m were established in a random-systematic manner in the direction of the slope of the region. Three functional characteristics of rangeland including stability, permeability, and food cycle were determined using LFA method and 11 soil surface indices. The results of this study showed that the indicators and functional characteristics of rangeland were changed due to the applied management practices. The independent t-test results showed a significant difference between three functional attributes within the patches and interpatches of each region compared to the control area (P <0/05). In addition, based on the results of variance analysis compared to the three improvement regions, the three functional attributes (stability, permeability, and nutrient cycle) were significantly different at 1% level. In general, the results of this study showed better conditions for Mesquite tree planting and contour furrow construction in terms of functional characteristics compared to the Eucalyptus tree site. Thus, it can be stated that improvement practices resulted in improved rangeland health.