حامد سنگونی

Successful pasture improvement plans rely on selecting suitable planting locations for each plant species. Identifying the potential habitat of plant species and planting them in appropriate areas significantly increases the plan's success, facilitating environmental restoration. This study aims to model the habitat of Iris songarica Schrenk, commonly known as desert iris, in Torbat Heydarieh County using Ecological Niche Factor Analysis (ENFA).

Presence data for Iris songarica were collected from 34 points through field surveys and direct observations, recorded using GPS. These points were considered suitable areas for iris growth. Environmental variables, including physiographic (three variables), soil science (seven variables), and climatic (nineteen variables) data, were incorporated into the ENFA model. Initial mapping of these variables was conducted using ArcGIS software. The ENFA model was then applied, and statistical analyses such as normalization and correlation were performed in Biomapper software to generate the potential habitat map of Iris songarica using the geometric mean method. Habitat map evaluation was conducted using Cross-validation tests and the Boyce index.

Marginality, specialization, and tolerance indices were calculated as 0.536, 10.015, and 0.1, respectively, indicating Iris songarica's preference for central habitat variables and its specialization in tolerating a specific range of environmental conditions. Direction, electrical conductivity, annual temperature range, temperature homogeneity, silt percentage, carbon content, average daily temperature range, and total rainfall of the coldest consecutive quarter were identified as the most influential factors in determining the habitat of Iris songarica. Climatic variables related to temperature had a greater impact on species distribution than those related to rainfall. Out of the four significant climatic variables affecting Iris songarica's distribution, three were temperature-related, while only one was related to rainfall. Approximately 66.16% of the study area was classified as unsuitable habitat, with 14.7% identified as potential habitat. Boyce's index revealed a model accuracy of 94%, indicating its reliability.

Ecological Niche Factor Analysis proves effective in predicting Iris songarica's distribution in the study area with satisfactory accuracy. The results can inform various pasture management endeavors, aiding in the protection, utilization, and restoration of Iris songarica habitats.

This study was carried out with the aim of investigating and knowing the chemical and physical characteristics of Astragalus parrowianus Fischer and the relationship of these characteristics with soil and topographical characteristics in Jalamabadan rangeland of Joveyn city. At first, the studied area was divided into four places where A. parrowianus was present for sampling. In July and August of 2019, the study area was visited to take samples of tragacanth and then by using of scientific resources and the guidance of local operators, 4 different sites with the presence of A. parrowianus were identified. Then, in each of the places, the tragacanth was extracted from the plant bases and A profile was dug at a depth of 0-60 cm in order to prepare a soil sample. Quantitative characteristics of tragacanth, including production, ash, viscosity, and qualitative characteristics of Tragacanth, including potassium, calcium, phosphorus, and sodium elements, arabinose, galactose, fructose, glucose, sucrose sugars, and proline, serine, and valine amino acids were measured. In the collected soil samples, the factors of electrical conductivity, percentage of sand, silt, clay, pH, soil water saturation percentage, potassium and organic matter were determined in the laboratory using standard methods. Also slope, aspect and elevation maps were prepared in order to determine the topographic characteristics. Then, using one-way analysis of variance, the difference between the sites was investigated in terms of quantitative and qualitative characteristics of tragacanth and soil characteristics. Finally, using the Redundancy Analysis (RDA), the relationship between the environmental characteristics and the characteristics of tragacanth was investigated. Among the soil characteristics, the amount of organic matter, the percentage of clay, sand, the amount of gravel and electrical conductivity have significant differences in the studied sites. While potassium, pH and percentage of silt have no significant difference among the studied sites. Except for valine, magnesium, sucrose and galactose, the physical and chemical characteristics of tragacanth have significant differences among the investigated sites. Site 1 has the lowest amount of viscosity, calcium, sodium, fructose, proline and the highest amount of product and ash. Site two has the highest amount of potassium, phosphorus, arabinose, glucose, and proline. The third site has the highest viscosity, calcium and serine and the lowest sucrose and galactose. Site four has the lowest amount of ketira, potassium, phosphorus, arabinose, glucose, ash, serine and the highest amount of sodium and fructose. Also, about 90% of the changes are justified by the first axis of the RDA diagram and the variables of height above sea level (72%), soil alkalinity (42%), slope direction (36%), electrical conductivity (34%) and slope percentage (33%) were the most important effective factors in differentiating the different growth locations of A. parrowianus in Jalmabadan region. According to the results, the characteristics of tragacanth gum are influenced by environmental factors, and each of the characteristics of tragacanth gum are affected by certain environmental characteristics. From this, for various industrial purposes that certain characteristic of Katira gum is important, it is necessary that the effected environment in which the species grows or its gum is harvested should be in optimal conditions.

Increasing the consumption of medicinal plants has many benefits, including creating employment and generating income for producers, especially in rural communities whose livelihoods are highly dependent on nature. Therefore, it is necessary to investigate the factors affecting the consumption of medicinal plants and its status in the market in order to provide the most important factors for the development of this type of exploitation. This study examines the presentation and consumption of medicinal plants and the attitude and belief of people in it in the perfumeries of Torbat Heydarieh. Descriptive research method and collection tool was done using a questionnaire designed by the researcher. The statistical population of this study was the most important and significant perfumers of Torbat Heydariyeh and buyers of medicinal plants. The sample size using the Cochran's formula is equal to 383 which includes127 prominent perfumers of Torbat Heydarieh city and 256 buyers of medicinal plants were selected. After collecting the data by a questionnaire, the research data were analyzed using SPSS23 software. The results showed that there was a significant and positive relationship between the manner of keeping medicinal plants and the amount of consumption of people (r = 0.32) and the relationship between the supply of medicinal plants and the amount of consumption of people (r = 0.390) Was obtained. Between people's attitudes and beliefs about the effectiveness of medicinal plants and Consumption of people (r = 0.582) and a significant and positive relationship was obtained between having a degree related to medicinal plants and the amount of consumption of medicinal plants by people (r = 0.376). Therefore, only by increasing the awareness of consumers about the benefits of using medicinal plants and also by changing the way of supplying medicinal plants from traditional to modern methods, it is possible to help the development of the market of medicinal plants.

Rangeland create various products and services for the users, but currently livestock grazing (forage) is considered the first priority for the exploitation of rangeland. Paying attention to the differents types of services provided by rangeland and determining the economic value of these services helps managers in improving planning and optimal management, creating jobs and increasing the income of users. The purpose of the current research is to investigate the economic value and compare the income of forabge and medicinal production of Jalambadan rangeland in Joveyn County.

In order to determine the homogeneous areas of vegetation and to study more accurately and easily different parameters related to rangeland production, the rangeland was classified. Then the floristic list of plant types was prepared. Vegetation sampling was done in the representative area of each vegetation type using six 50-meter transects and 1×2 rectangular plots, and the number of plots was estimated to be 368 based on Cochran's formula. In order to calculate the annual plant production in each type of rangeland, the double method was used. Based on this, the amount of fodder production has been estimated in all the plots and only 25% of the plots were cut. In this research, 50% exploitation limit is considered. The estimation of the production of medicinal plants is different according to the organ used for them. Therefore, after identifying medicinal plants and edible organs, the appropriate production estimation method was chosen. Alternative cost method was used for economic estimation of fodder production. Therefore, among the exchangeable plants, the barley plant has been chosen as an alternative product due to its exchangeability in global and local markets. The market price method was used to determine the economic value of medicinal plants.

Six plant classes and 119 plant species were identified in the study area. The results showed that the total forage production rangeland was 1180 tons in the entire area of the and the available forage was 590 tons, and the average forage production per hectare of Jalambadan rangeland was 144 kg. The economic value of fodder available in the entire area of pasture is equal to 805,775,000 Tomans.  The economic value of each hectare of rangeland in terms of available forage was estimated as 98,241 Tomans. According to the results, the production of available medicinal plants is equal to 256 tons and its economic value is equal to 2,845,000,000 Tomans in 2019. The income of medicinal plants after deducting harvesting costs in 2019 was 1,440,000,000 tomans. The medicinal plants income per hactare estimated 175,672 Tomans. The results show that the exploitation of medicinal plants has 1.78 times higher income than the exploitation of forage plants.

Exploitation of medicinal plants is an activity with high economic value and is a good source of income for rangeland users. In addition to forage, as a source of income for the pastoralists, the harvesting of medicinal plants and their processing can be developed to reduce the pressure on the rangeland.

Understanding the behavior of plants in relation to ecological factors provides basic information in order to improve and properly use rangeland. Also, determining distribution area of species and studying the characteristics of their habitat helps to choose the right place for their establishment. Rheum species is one of the rangeland species which, in addition to having important medicinal properties, is valuable for soil protection in dry and semi-arid rangeland. Considering the decrease in the density of this species in natural habitats during recent decades, knowing the characteristics of the habitat can be an effective help in the improvement and development of Rheum. Therefore, in this research, the effect of environmental factors on the vegetative characteristics of rhubarb species in three different habitats is investigated.

In this research, the habitat characteristics in three habitats of Chubak, Targh and Karkaz in the Kouhsorkh region located in Kashmar city and the relationship of ecological factors with characteristics of Rheum ribes L. including excluded base weight, stem weight without pods, length of stems of a plant, and number of stems in each base have been investigated. The ecological factors included soil factors such as EC, pH, N, P, K, organic matter, clay, silt, sand and physiographic factors include slope, aspect and altitude. in each the studied habitat, 10 samples of Rheum ribes were collected. In the first stage, the weight of each harvested stem was measured and then the weight of stems without pods was determined. Also, the number of stems in each sample was counted and the length of each stem was measured separately. Finally, the matrix of environmental conditions and vegetative characteristics of Rheum ribes was analyzed using redundancy analysis (RDA).Method

The findings of the research showed that the characteristics of the soil in Chubak, Targh and Karkaz sites are different and in the same site it is different in different soil depths. Among the physiographic factors, the altitude has the greatest role on the characteristics of the Rheum ribes. The altitude has a positive and strong relationship at a significant level of 5 percent with the length and number of Rheum ribes stems. So that with the increase in altitude, the length of their stem also increases. Among the soil characteristics, the percentage of sand, silt, P, K and lime percentage are the most important factors affecting the characteristics of Rheum ribes. The percentage of sand has a srtrong correlation with the weight of the Rheum stem, and with the increase of the percentage of sand, the weight of the stem increases. EC parameters and silt percentage have a negative relationship with Rheum ribes characteristics. So that with the increase of these parameters in the soil, the number and length of stems as well as their weight decreases.

The results of this study showed that Rheum ribes in Chubak site has the highest amount of growth characteristics, therefore Chubak region has provided more suitable conditions for growth of this species than the other regions. In this site, the samples of Rheum ribes have the highest number of stems and the highest average weight of the stems at 1316 gr. Therefore, this site can be introduced as the best growing area for Rheum ribes. Also, in terms of environmental parameters affecting the growth characteristics of Rheum ribes, among the topographic factors, altitude, among soil properties, the percentage of sand, silt, phosphorus, potassium and lime are the most important factors affecting the characteristics of Rheum ribes.

Climate change which has begun due to human activities in the past centuries, intensified through positive feedbacks as time goes by. Changes in the characteristics of the environment of organisms definitely affect their lives. In the last decade, many studies have focused on the type, size, and extent of this effect on different organisms (including plants) in various ecosystems. In this study, the effect of climate change on the geographical distribution of Anchusa italica in Khorasan Razavi province was investigated at 2080 with RCP 8.5 and under the HadGem2 general circulation model. Despite its medicinal, conservational, economic and even forage importance, this species has never been studied. The impact of climate change on important species can only be examined through modeling, because modeling studies in the natural sciences are the key of many issues that cannot be tracked in normal studies.

At first, field studies were carried out including the record of geographical coordinates of the species presence in the rangelands of Khorasan Razavi province in late spring of 2018 (when the plant was flowering and easily visible and identified) and 113 presence points was recorded for Anchusa italica. Then the 19 bioclimatic variables alongside three topographic variables were used as inputs to GBM model. This model, which is a decision trees based methods, uses numerous incomplete trees to form the final model, and the algorithm required in this study was programmed in the R environment. The model simulates the relationship between the presence of species and climatic and topographical conditions, and then uses this simulation to study the effect of changes in climatic factors on the distribution of species. Two validation indices (AUC and TSS) were used to determine the model's potency.

The maps of suitable areas for wild borage in current climatic conditions and under climate change in 2080 were prepared and the model assessment indices showed that the model has a high ability to predict suitable sites for species presence (AUC = 0.974 and TSS = 0.87). Habitat suitability of this species was highly affected by (BIO1), (BIO2), (BIO15) and (BIO12). Results showed that in comparison with current conditions, about 40% of the climatic suitable area for this species will be diminished with the RCP 8.5 (from the IPCC scenario series). The areas where changes in the habitat of this species occur are displayed in a map.

The effect of climate change on plants is divided into three groups: Adaptation, Shifting and Extinction. According to the results of this study, in the case of wild borage, physiological adaptation is not likely to be possible in the short term (less than few centuries to few millennia). So if this plant fails to alter its distribution range (Shifting or displacement), will have to choose the third way (local extinction or get limited to refuges). Therefore, it is necessary to plan local, national and regional programs to maintain and extend the current habitats of this biological, ecological, medicinal and economic important species and providing access to new habitats for it; alongside the preventive activities of climate change.

One of the major impacts of climate change on plants is the change in their geographical range. Predicting the potential distribution of endangered plants in response to climate change is essential for their conservation and policy management. This study aimed at predicting the effect of climate change on the geographical distribution of Fritillaria imperialis in Chaharmahal & Bakhtiari province in the central Zagros region. We used RCP4.5 and RCP8.5 (two climate change scenario) and general circulation model HadGEM2-CC in order to predict the future geographic distribution of the species. In this study, we used 19 bioclimatic variables related to rainfall and temperature and three physiographical variables to create the models. In this regard, we used 5 modelling approaches, Generalized Linear Model (GLM), Classification Tree Analysis (CTA), Artificial Neural Network (ANN), Generalized Boosting Method (GBM) and Random Forest (RF) under the ensemble using biomod2 package in the free statistical software environment R 3.3.2. The results of the model showed that annual precipitation and temperature seasonality had the most important to provide habitat suitability of this species. All the models were accurate enough to predict the species distribution, among them, RF presented the most reliable model for the prediction. Under RCP4.5 and RCP8.5 climate scenario, the habitat of the species will shrink to 19.7% and 61, respectively in 2050.

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).

Predicting the potential distribution of plants in response to climate change is essential for their conservation and management. This study aimed at predicting the effect of climate change on the geographical distribution of Pistacia atlantica in Chaharmahal & Bakhtiari province in the central Zagros region. In this study, we used 19 Bioclimatic variables derived from rainfall and temperature and three physiographical variables as the input of maximum entropy model (MaxEnt). The results showed that annual precipitation, annual temperature range and seasonal temperature have played the most important role in habitat suitability of this species. The results of the model showed that 14.7%, (2413.7 km2) of in Chaharmahal and Bakhtiari Province for the Pistacia atlantica have had high habitat suitability. Under RCP4.5 and RCP8.5 climate scenarios, Pistacia atlantica might lose (Respectively 8.11% and 11%) of its climatically suitable habitats due to climate change factors by 2050. Considering the high accuracy of the maximum entropy model in predicting the distribution of the studied species (AUC = 0.92), results of this study can be used in planning, conservation and rehabilitation of Pistacia atlantica.

Grazing is an effective factor on many aspects of plant species and communities. This anthropogenic factor, which became a destructive operant in Iran due to mismatch to range capacity, can affect the individuals of a plant species and thus, alter its spatial distribution. In the current study, the effect of short term exclosure on geographical distribution of two cool season grasses (Bromus tomentellus and Agropyron trichophorum) investigated using historical presence data. To do so, SRE modeling method (which is a presence-only model) was used to generate distribution maps before and after applying the exclosure. Presence coordinates of each species determined from 98 permanent exclosures. The number of B. tomentellus presence spots were 31 and 37 points before and after applying exclosures; respectively. The number of A. trichophorum presence spots were 16 and 25 points before and after applying exclosures; respectively. 19 bioclimatic variables used as environmental variables. The results indicated that the area of suitable climatic habitat of B. tomentellus before applying the exclosure (125868 ha) was considerably more than A. trichophorum (32515 ha). Nonetheless, applying the exclosure caused a 58% increase in suitable habitat of A. trichophorum versus 9% increase for B. tomentellus; which suggest that the grazing had a higher relative influence on A. trichophorum and removing the grazing pressure capacitated this species to retrieve its habitats. It should be emphasized that B. tomentellus should be considered as a more tolerant species to climatic conditions due to its prevalent distribution.

Wind erosion and the influx of sandy soils to economic facilities and biological resources are one of the main problems in the country. 14 provinces, located in arid and semi-arid regions, face wind erosion. Wind erosion and the influx of sandy soils are two important indicators in the occurrence of desertification and a serious threat to arid areas. The best and lasting way to prevent erosion is to deploy natural vegetation in areas at risk. But this will require a minimal fit for environmental conditions for the environment, and vegetation cannot be established in areas where these conditions are not met. For this reason, non-physical methods, such as the use of wind turbines and various types of mulches, are also of interest, each of which can, in certain circumstances, have the highest efficiency and efficiency. The mulch is defined as a coating that protects the soil from contact with the wind erosion current. In this study, the use of steel slag as a mulch for controlling wind erosion from different dimensions has been investigated.
The selected area for field studies was located in Zebarkhan district of Neyshabour, near YousefAbad village. This area was selected according to the characteristics of erosion soil and regular wind power regime. Soil sampling was used to study the soil characteristics of the area and acidity and its salinity were determined. The atomic absorption method was used to measure the amount of heavy metals in the slag compound which is important in terms of environmental issues. The appropriate size of slag was 3 to 4 cm. Two thousand square meters were used for treatment and erosion measurements in YousefAbad area of Neyshabour. The two pieces were placed on the ground, both of which are perpendicular to the direction of the dominant and erosion of the wind. To determine the effect of applying slag mulch on each treatment and control part, nine fixed trays were placed on each 15 mm soil tray. Then, at 1-month intervals, the depth of soil was measured on each tray by a caliper and accurately one hundredth of a millimeter. The results of these two groups were compared using t-coupled test.
The soil of the study area was Aridisol and its salinity was 1.408 dS m-1 and its pH was 7.48. Soil study using hydrometric method showed that 56% of this soil was Silt, 31% sand and 13% Clay. So the texture of this soil is silty loam; one of the most erodible types of soil in wind erosion. The results of measurements of heavy metals of chromium, cobalt, lead and cadmium by atomic absorption method showed that the amount of lead, cadmium and cobalt in slag is less than the critical level defined for them and their presence in the slag compound will have small impacts on the environment. But in the case of chromium, it was significantly high and should be considered as a potential risk factor. The results of measurements of soil changes in the studied parts showed that not only erosion was controlled in the slag mulch treatment part but also to the sedimentation occurred. However, there has been significant soil erosion in the control unit. The results of the comparison of these two groups using the t-test showed that there was a significant difference between them at 1% level and therefore, slag treatments had a positive effect and was able to control wind erosion in the study area. Considering all costs, the application of this kind of treatment in the studied area cost 642 thousand Tomans.
Discussion and The amount of heavy metals in most cases except chromium was not alarming. Considering the fact that chromium is one of the most hazardous substances for the environment, steel and iron slag should not be used without the precautions at large scales. Of course, it's important to note that only chromium 6 (Cr VI) is known as a toxic compound, and it quickly turns into chromium 3 (Cr III) in nature, which is a micronutrient needed by various living organisms. Also, since this chromium may not be free at all, the issue of the release of chromium in slag by natural processes should also be considered. According to the results of the measurements carried out in this study, it can be confidently stated that the use of slag mulch has a clear effect on reducing wind erosion in studied area. Even with regard to the results, it can be argued that this mulch, in addition to preventing soil particles from being removed by wind, can also trap eroded particles that are transported by wind in the creeping or jump process. Therefore, from an operational point of view, slag can definitely be recommended for the wind erosion control. These results are similar to those of Safaie (2012) and Babakhani (2011). Also, the results of Li et al. (2001) showed that the pebble mulch has not only the ability to control erosion, but also has a high capacity to trap wind deposits. If there is no potential area for effective vegetation cover in erosion control, or if wind erosion and dusts are required to be controlled quickly, this type of mulch by the coverage rate of 75% and the proposed particle size (3-4 cm) can do it well.

Climatic conditions largely determine the status and characteristics of plants and plant communities in different regions. Therefore, in order to study range plant species, the tolerance of each species to these factors should be determined. In this study, climatic features and requirements of two important grass species with conservation and forage importance (Agropyron trichophorum Richt. & Bromus tomentellus Boiss.) were studied in the Central Zagros. For this purpose, 19 bioclimatic variables used as inputs to Random Forest (as a machine learning approach) in R statistacial environment. The results showed that total annual precipitation (BIO12), the average temperature of the wettest season (BIO8) and the mean diurnal range (BIO2) for both species had the greatest importance and the sum of these three variables described more than 68 and 64 percent of variance in the B. tomentellus and A. trichophorum, respectively. The estimated accuracy by TSS index was calculated for B. tomentellus as 0.95 and Sensitivity and Specificity values were estimated as 0.93 and 0.96, respectively. For A. trichophorum, these values (TSS, Sensitivity& Specificity) calculated as 0.92, 0.89 and 0.93; respectively. The results of this study explain the cliamtic niche of the studied species. Top priority places, where protective actions has to be taken, can be determined using the results of this study. Potentially climatic suitable habitats can be proposed for reintroduction of these valuable species as well.

Organisms need a variety of mineral nutrients for their normal functioning; some of these nutrients are needed in large quantities, while others are less essential. In this study, the effect of plant growth on macro mineral contents of the important plant species of nomadic grasslands of North Khorasan province was studied. Random sampling of dominant species in upland, lowland, and intermediate ranges was conducted at three phenological stages: vegetative growth, flowering, and seeding. For each species and at each growth stage, five randomly selected samples were chosen from different parts of the vegetation types, with each sample containing three individual plants. Data analysis was performed using one-way analysis of variance and Duncan test to track the inter-group changes. The amount of theseelements was compared to their critical levels to meet the animal unit maintenance needs using T-test. The results showed that in general, the amount of every macro nutrient is more at the vegetative stage in comparison to the seeding stage. In addition, their values in each of the growth stages were different between the studied species. The analysis of the macronutrients of the studied species at different regions indicated that in all three types of the studied grasslands, the species had more phosphorus, potassium, and calcium and less sodium, magnesium, and calcium/magnesium ratio than the average need of livestock at all stages of growth.

The effect of climatic changes including: temperature, CO2, and moisture content on photosynthetic characteristics and dry matter yield of rangeland species Bromus tomentellus Boiss – an important forage plant in the West of Isfahan province pastures – was explored in a factorial experiment with a completely randomized design. After collecting a mother plant of this species and asexual reproduction to required number, the climatic variables on each time step in the future (based on A2 climate change scenario) were applied as a treatment on pots except for one group which was taken as control. The photosynthetic pigments, including chlorophyll a and b, total chlorophyll, carotenoids, and aerial dry matter (as the criterion to determine the amount of plant yield in each pot) were measured in these groups. By recording these parameters and relating them to the climatic variables, the impact of climatic changes on them were explored. The results showed that the physiological response of species to the changes in the climatic parameters of temperature, CO2, and moisture content was different. A change in these three parameters (temperature, CO2, & moisture content) significantly decreased chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids in the species under the study. Dry matter yield of single pot also decreased significantly (p

The destruction of (AstragalusgossypinusFisch.) habitats in Isfahan province has had several environmental and socio-economic impacts. To restore these habitats by means of planting AstragalusgossypinusFisch., determining its potential habitats in the province becomes essential. In an attempt to fulfill this objective, first, the significant environmental and biological factorsof A.gossypinusFisch.in different habitats of the provinces were selected. The relation between them was then examined and illustrated in the form of RDA graphs. Afterwards, using the length of the vector in each of these environmental factors in graphs, their ultimate impact on the final model was determined and the potential habitats of this species across Isfahan province were identified by means of AHP approach. According to the results, the ecological characteristics required for optimizing the growth of A.gossypinusFisch.in Isfahan province rangelands include: 200-400 mm of precipitation, 100 frozen days per year, about 8 degrees of slope, 160 ppm K in soil, 30% clay, 40% sand, and pH of 7.9.

Astragalus gossypinus Fischer is one of the most important range plants in west region of Isfahan، which is very critical for soil conservation and people''s economic life. Nevertheless، the grazing pressure and overuses cause habitat destruction. This study has been done for determination of its potential habitat in Lenjan and Flavarjan parishes of Isfahan province. To achieve this purpose، spatial data of this specie''s presence used as suitable places for its growth and the environmental condition (Climate، Soil & Physiographic) used for recognition of its habitat''s necessities. Soil data turned to soil maps using antecedent studies and interpolating soil profile points. Climatic and physiographical data have been prepared as well and got ready to be imported to the ultimate model. By importing the information layers in ENFA model and using harmonic mean analysis in Biomapper software; the map of Astragalus gossypinus potential habitat has been created. The results show that gravel percentage، soil potassium، saturated moisture، electrical conductivity and annual precipitation are the most important factors in habitat choosing by Astragalus gossypinus in study area. 25300 hectares of the study site are potential habitat of Astragalus gossypinus which is 16 percent of the study site. To evaluate the verity of this model، Boyce''s index has been used and model rectitude in this test was determined 85. 2 percent.