راضیه صبوحی

 Increasing awareness of the environment and efforts for sustainable management of natural resources require study and monitoring in different time scales and places. Continuous changes should be considered as an inseparable part of any ecosystem. As natural ecosystems, rangelands are not exempt from this issue. So that rangeland monitoring is necessary in the sense of continuous investigation of these lands with regard to the ecological importance, economic functions and constant changes of these resources. Access to such data is extremely important both for national planning and for the use of rangelands, and it provides the basis for the use of advanced facilities such as remote sensing. Based on this, in order to monitor the trend and intensity of changes in vegetation cover and soil indicators of rangelands for 4 years at the Goorab site located in Isfahan province, it was evaluated and monitored.

The site of Goorab Fereydoonshahr Isfahan is located 230 kilometers west of Isfahan city and 35 kilometers west of Fereydoonshahr city. Plant factors including canopy cover of plant species and production rate of plant species and percentage of dead leaves were evaluated. Evaluation was done in the first year by random-systematic method and in the following years systematically with sufficient number of samples and appropriate distribution of samples in the plant type determined at the time of rangeland preparation. Soil sampling was done in the

The results showed that the 4-year average vegetation canopy cover percentage of Goorab site is about 42.2%, and the highest and lowest coverage is 59.4% in 1398 and 31.6% in 1400, respectively. The production rate is 1374.2 kg of dry matter per hectare. The production, like the canopy cover percentage, shows a lot of changes during the 4-year evaluation at the Goorab site, so that in 2019, the production reached 1957 kg per hectare, and in 2021, it decreased by 50% compared to 2019 to 955.7 kg per hectare. The results of the correlation and regression test also showed that the amount of precipitation in the growing season had the highest correlation with the amount of crown cover and production of plants in the region.

Considering the importance of rangelands, both in terms of production and in terms of environmental values and services they provide to the society, studying the changes of rangelands in terms of the aforementioned factors and knowing the factors of those changes will be an effective help in developing a basic management plan and sustainable use of rangelands.

Knowing the effective environmental factors in the establishment of vegetation can help the proper management of pasture ecosystems. A suitable habitat has a significant effect on the survival and reproduction of species. Revealing changes in climate parameters indicates that climate changes have started in Iran and it is necessary to determine the potential habitats of indicator species, now and in the coming years, under climate warning models. With the advancement of statistics and geographic information system, it has become possible to predict the habitat of plant species using modeling methods. Therefore, this research was conducted with the aim of preparing a forecast map of Platychaete aucheri habitats based on the climate forecast model in Sistan and Baluchestan province.

First, using 8 synoptic stations inside and nearby areas, the database including precipitation variables, night temperature, daily temperature and average temperature, from the year of establishment of each station until 2019, and 19 climate parameters were calculated. Also, three physiographic variables, including slope, direction and height, were prepared using a digital height model with an accuracy of 30 meters. Then, by using the updated maps of the ecological zones recognition plan and field visits, the presence and absence points of P.aucheri species were determined. The basis of the analysis used in this research is logistic regression, which is based on environmental values related to the presence and absence of species. Using logistic regression, the growth behavior of this species in Sistan and Baluchestan region was determined and the map was modeled and the relevant equations were calculated in the current conditions. After ensuring the efficiency of the model, the climate data predicted by the general circulation model MRI-ESM2-0 were used under the scenarios 4.5 and 8.5, and by using the current equations and placing the data extracted from the database, Worldclime, the future distribution map of the species P.aucheri was produced for 2050 under RCP4.5 and RCP8.5 climate scenarios. In this way, at the stage of defining the logistic regression model in ArcGIS, instead of the map of the climate variables that exist in the model, the maps of the same variables predicted for the year 2050 were placed.

The results of the potential maps showed that the current distribution of the species, P.aucheri, had a more colorful presence in the central and southern parts, and the percentage of the presence of the species decreased by moving towards the northern regions. The area of suitable habitat (probability of occurrence greater than 75%) of P.aucheri species in the province is equal to 12873269 hectares, approximately 71%. The evaluation of the model was done using the data of the presence and absence of the species and using the Kappa statistical coefficient. In this connection, the value of the Kappa statistical coefficient was obtained as 0.85, which according to the presented classification of the Kappa coefficients, the model has good and acceptable accuracy. It is acceptable. The maps resulting from the prediction of the logistic regression model show that the habitat area of ​​P.aucheri species will increase significantly in 2050 under both RCP4.5 and RCP8.5 scenarios, and it is observed that the habitat area of ​​P.aucheri species is more than 75% more likely to occur. In the province, it will be equal to 15506391 and 17788376 hectares, respectively, which will occupy a surface equivalent to 85.3 and 97.85%, respectively. Under the RCP8.5 scenario, the probability of the presence of the species will increase greatly, and it can be seen that the probability of the presence of this species in the lower floors reaches 50% to zero. 

In general, climate change and the consequent increase in temperature indicators will preserve the current habitat, increase the probability of the presence of the species in the entire province, and the vertical expansion of the P.aucheri species and its movement to higher latitudes along the altitude gradient of the region. Therefore, the expected upper limit of the vegetative range of P. aucheri species will undergo changes during the next three decades.

Understanding the impact of climate change on plant species distribution is crucial for effective rangeland management and conservation. Climate change often results in shifts in the geographic rangelands of plant species, altering their tolerance and propagation zones. To study and mitigate the consequences of climate change on potential habitats of plant species, species distribution models are employed due to the complexity of natural ecosystems. In this study, the current and projected future habitat rangelands of Artemisia aucheri species in Chaharmahal va Bakhtiari province for the year 2050 under RCP4.5 and RCP8.5 scenarios were investigated using the logistic regression model.

First, the map of the presence and absence of A. aucheri species was prepared from the updated map of the country's ecological zones plan. And based on field visits and observations while modifying the map, the occurrence points were collected. In order to prepare a prediction map of the current and future range of the selected species, the statistical method of logistic regression was used. For this purpose, 19 bioclimatic variables and three physiographic variables (slope, aspect, altitude) were entered into the logistic regression model as independent variables and species presence and absence variables as dependent variables and the corresponding equation was obtained. After ensuring the efficiency of the model for predicting the geographic distribution of the selected species in 2050 by the general circulation model MRI-ESM2-0 under RCP4.5 and RCP8.5 scenarios, the results were converted into a map in ArcGIS 10.5 software.

Based on the results, among the bioclimatic and topographical variables, only temperature-related indices including BIO1 (annual temperature), BIO7 (annual temperature range) and BIO10 (average temperature of the hottest month) were identified as effective on the distribution of A. aucheri species. The values of the temperature indices will increase as the climatic conditions become more difficult under the RCP8.5 scenario, and as a result, the level of suitable habitat (probability of occurrence above 75%) of A. aucheri species will decrease and under RCP4.5 and RCP8.5 scenarios, the habitat of the species will be moved to higher altitudes by 120 and 170 meters, respectively.

Climate change-induced temperature increases are expected to alter the vegetation rangelands of A. aucheri species, pushing it towards higher altitudes. Consequently, the lower and upper limits of the species' vegetation rangelands (1800-2600 meters) are projected to shift over the next three decades.

Research has been done on different materials to control and reduce wind erosion. Among them, we can mention the performance of agar gum biopolymer in reducing dust production at different concentrations of 0.5, 1.0, and 1.5%. Its results showed that the addition of biopolymer improves the water-holding capacity, increases the surface and compressive strength of the soil, and decreases dust production. In another study, agar gum biopolymer significantly improved soil mechanical properties. This study investigates the effect of polymer nuclei (M19) on controlling sand dunes. This research investigates the effect of nucleos (M19) mulch on reducing wind erosion and controlling sand dunes and dust.

This research was carried out in Segazi Plain, a study and implementation priority due to its proximity to urban areas, military facilities, transportation, as well as industries and workshops located there, from the aspect of preventing wind erosion and desertification. After choosing the field, two plots of 500 square meters with the same conditions (an active hill with an area around it with natural and hand-planted vegetation) were selected. To determine the effect of soil cover, the area of each plot was determined by wooden stakes. In addition, the surrounding sand dunes were staked to measure their displacement. A pump sprayer mulched the measuring plot with nucleos (M19) mulch. Following the soil moisture changes, information including seedling survival and growth rate, soil cover's ability to control sand dune displacement, and compressive stress was examined during different months. Finally, the effectiveness of soil cover was compared with the control treatment using the T-test.

 The results of examining the changes in humidity and the effect of soil cover on it showed that the highest humidity in the area was after rain. No clear difference was observed between the drying process of the control plot and the mulched plot. It was also found that this mulch positively affects seedling growth rates. During the research period, the control sand dunes moved about 0.75 to 2.5 meters depending on the season and wind direction. In contrast, the mulched sand dunes remained stable. On the other hand, with time, the mulched field's surface became flaky, and signs of wear and tear were observed.

The first point about using this polymer as a soil cover is its two phases during transportation and storage until mulching. In such a way, the two layers can be clearly distinguished. As a result, mixing is necessary for the uniformity of the polymer during the preparation of the final emulsion. This can be considered as one of the negative characteristics of the used polymer. This mulch positively affected soil moisture changes and increased soil moisture retention. On the other hand, the comparison of the growth of the seedlings in the mulched field and control also shows its effect on the growth of the seedlings. This soil cover's only positive and critical feature is its high flexibility after mulching in such a way that it is possible to drive on it with caution. Finally, after a year, cracks were first detected in the research field. Gradually, the number and depth of cracks increased, which caused the mulched field surface to become flaky. Following this complication, instability and signs of wear and tear were observed in the mulched area. However, no movement or change in location was observed in the mulched hill. It should be noted that with time, more destruction occurs on the surface of the mulched area. Following more flaking, the mulched surface may be destroyed, and hill erosion may begin. Considering these cases, mulching in this and similar areas is not recommended.

Climate change has been a serious issue in the last two decades and many studies have focused on its various aspects. Therefore, it is necessary to determine the potential habitat of rangeland index species, currently and in the coming years, under climate warning models. Therefore, in the present study, by preparing a prediction map of the current and future range of Bromus tomentellus species, under two climate warning models (Rcp4.5 and Rcp8.5 scenarios), its movement, in latitudes, at the level of rangeland ecosystems of Ardabil province was investigated.

For this purpose, in the growing season of 2020, from 19 bioclimatic variables and three physiographic variables and a logistic regression model, to determine the quantity of climate change in the next three decades (2050) and to carefully examine its effects on the change in the range of B. tomentellus species now and in the future, used. The output maps are divided into four categories with the probability of occurrence between zero and one; unsuitable habitat (0-0.25), almost suitable habitat (0.25-0.5), habitat with high suitability (0.5-0.75) and habitat with very high suitability (0.75-1), it was grouped and based on the coefficients of the variables in the regression relationships, the effective variables for the current and future range were introduced.

The average annual temperature (BIO1), the annual temperature range (BIO7) and the average temperature of the coldest season (BIO11) are the most important for the suitability of the habitat, and their values increase with the harsher climatic conditions. The average annual temperature of its suitable habitats will increase by 1.6 to 2.1 degrees Celsius in the next three decades. The height of its suitable habitats will increase from 115 to 190 meters. As a result, the level of its suitable habitat decreases in response to climate change. Also, under climate scenarios, 30.2% of suitable climate habitats will be lost in 2050, and current unsuitable habitats will increase by 29.4%.

In general; climate change and increase in temperature will cause B. tomentellus species to move to higher latitudes along the altitude gradient. Therefore, in the next three decades, there is a risk of removing it from the rangeland ecosystems of Ardabil province.

Understanding the environmental factors affecting the establishment of vegetation, can help in the proper management of rangeland ecosystems. Optimal habitat has a beneficial effect on the survival and reproduction of species. With the advancement of statistical science and GIS, it has become possible to predict the habitat of plant species using modeling methods. Therefore, the present study was conducted with the aim of preparing a forecast map of B. tomentellus habitats based on the climate forecast model in South Zagros (Fars province). First, using 29 synoptic stations inside and adjacent areas, a database including variables of precipitation, night temperature, daily temperature and average temperature was formed and 19 climatic measures were calculated. Also, using a digital height model with an accuracy of 30 meters, three physiographic variables including slope, direction and height were prepared. Then, using updated maps of ecological zones and field visits, the presence and absence points of B. tomentellus were identified. Using logistic regression, the growth behavior of this species in the South Zagros region was determined and the model map and the corresponding equations were calculated in the current conditions. Using current equations and placement of data extracted from the Worldclime database, the future distribution map of B. tomentellus for 2050 was generated under the RCP4.5 and RCP8.5 climate scenarios. The results showed that B. tomentellus species will migrate to higher altitudes of 170 and 260 m, respectively, in the RCP4.5 and RCP8.5 scenarios. Also, the area of ​suitable habitat areas, from 26.8% of the area of ​South Zagros rangeland habitats in the current conditions, to 8.5% under the RCP4.5 scenario and 1.7% under the pessimistic scenario (RCP8.5) in 2050 Will be reduced.

Identification and assessment of the relationship between medicinal plant species and climatic factors are important lines of research, which provides insights into reasonable exploitation and sustainable development of these species. In addition, multivariate statistical methods have been proved successful in revealing the relationship between climatic factors and the distribution of plant species. Hence, this study aims to investigate bioclimatic characteristics of Daphne mucronata by determining climatic factors in its distribution range in Fars Province, Iran, where this species has a wide spatial distribution (27% of the total area). Towards this aim, 50 climatic variables related to January, April and July were used. To reduce the number of variables and determine the most important factors, Factor Analysis and Principal Component Analysis (PCA) were used. The results showed that four principal components namely the temperature, precipitation, cloudiness, and wind components account for 38.56, 32.85, 11.03, and 9.09 % (91.54% in total) of data variance, respectively. The results also indicated that temperature and precipitation had the greatest impact on the species distribution. Moreover, the mean temperature within the species distribution range was about 15°C with minimum precipitation of 379 mm. This research identifies the characteristics of vegetative climate to determine the possibility of expansion and development of this plant in natural areas and provides better management.

Drought stress is the most important factor in the growth of plants in arid and semi-arid regions and plays an important role in the establishment of plants in these ecosystems. Russian olive seedlings were planted in environmental plan in the form of Complete Randomized Block Design (RCBD) with four replications and treat mental plan in the form of factorial with 2 factors in the greenhouse. The test factors were Arbuscular mycorrhizal inoculum (Rhizophagus irregularis, Funneliformis mosseae and control without inoculation) and four drought stress intensity (25, 50, 75 and 100% of field capacity (FC)). Seedlings growth rate include height, collar diameter, number of leaves, number of branches, weight of aerial and underground organs was calculated by comparison of the growth rate at the beginning and end of the experimental period. With increasing drought stress intensity, vegetative traits such as height, collar diameter, number of branches and leaves, root dry weight and shoot dry weight of Russian olive seedlings were decreased significantly. With increasing drought stress to 50% of FC, the main root length of seedlings showed an increasing trend, indicating an increase in root length under dehydration. The highest and lowest dry weights of seedlings shoot were observed in treatments of F. mosseae and control, 36 g and 18 g, respectively. Fungal species of F. mosseae in all morphological traits except root dry weight provided more favorable conditions for the seedlings, as well as the F. mosseae, showed more abundance and better coexistence with Russian olive seedlings.

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

For the experiment, at the beginning of each growing season, an adult Naiini sheep (3-4 years old) was used as representative of the herd and used in annual censuses. Grazing time measurement continued at the beginning of the growing season and during the four growth stages. Census time at each growth stage was performed one hour after daily grazing, and in three continuous 20-min periods (repeat experiment). Considering the time of concentration of the animal and the tendency of the animal to different species, the palatability class of each plant species was determined. The results showed that during all the years under study, grazing concentration of Naiini sheep on annual species (Grass and Forbes), litter, Stachys inflata, Artemisia sieberi, Stipa arabica, Noaea mucronata and Hertia angustifolia was observed. Based on the results, annual and litter species were classified as Class І species, Stachys inflata as Class II plant and Artemisia sieberi, Stipa arabica, Noaea mucronata and Hertia angustifolia as Class Ш species. The results showed that the palatability of the species was not the same as the change in plant composition during the growing season. Therefore, it is incorrect to consider the same palatability class for each species at different stages of development, and it is necessary to pay more attention to the description of pasture design services when calculating grazing capacity.

This research was carried out aiming to investigate positive and negative aspects of watershed practices and their effects on quantity and quality of water resources in Budejan River basin. This river is one of the main branches of Shour-Dehaghan River and its area plays an important role in supplying water for lower lands. In this regard, meteorological data, hydrology and other information and maps were collected. The volume of dam reservoirs and the amount of rainfall within two years of the project were measured by field studies and hydrology studies were carried out by field measurement and assessment of hydrologic conditions of the basin. Results showed that the water content generated by these practices is enough to recharge groundwater. Construction of dams tended to decrease water flow rate and reduced the destructive effects of seasonal flood and with increasing water infiltration rate, it has increased aquifer recharge in the study area. The low volume of dam reservoirs has not caused irregularity in water supply of downhill lands. However, the lack of proper management of these operations and the excessive development of gardens and agricultural lands, due to the ease of access to water, overshadow positive results of watershed practices and offset it by a very high cost.

The genus of Astragalus accounts for 31.4 percent of area of Isfahan Province with Astragalus verus Olivier as a foremost species. This study aimed to investigate the contributing climatic variables to distribution of this species. Moreover, the trends of climatic variables and their influence on the species mortality. In doing so, 56 climatic variables relating to January, March, July, and the entire year were utilized. The Principal Component Analysis was employed to trim down the number of variables and their trends were analyzed using the Mann-Kendall test. The correlation analysis was ultimately used to investigate the association between climatic changes and mortality of Astragalus verus. Results showed that cooling temperature contributed most in the distribution of the species. The trend of temperature also indicated that mean temperature followed an upwards trend in most months of the year. Except Ardestan, Isfahan, Eastern Isfahan, and Kaboutar-Abad, annual precipitation declined but not significantly at the level of 1 and 5 percent. The dried up stands observed in Naeen region was estimated to be around 25 percent where the largest decreasing precipitation and increasing temperature was recorded. This estimate was only around 8 percent in Khansar and Chadegan whose increasing temperature and wind speed as well as decreasing precipitation were compensated by having a good growing potential.

Marl formations have problems in watersheds due to high sediment yield. The purpose of this research is the marls classification of Isfahan province according to erodibility indices and their physical and chemical properties. In this regard, region marl units were identified and their sediment yield was measured using rainfall simulator. Then, based on erosion type, they were sampled and soil physical and chemical properties were analyzed. Cluster analysis statistical method was used to classify marl units. Statistical analysis was performed by three sets of data including chemical, physical and both chemical and physical accompanied by slope and measured sediment from six mmh-1 rainfall in each step of the analysis. Results showed that the most important similarity factors in marls are chemical properties and the effect of climate. According to information obtained from investigations, climate is the most effective factor of differences among marl units in this province. In addition to its direct impact on creation and evolution of marls, it affects on other parameters directly and indirectly and choosing either of these parameters is related to climate.

Climate change is one of the most important phenomena in recent years have been affected on natural resources and especially the communities whose livelihoods in relation to natural resources, as well as prediction of climate parameters in order to achieve future changes and regard to adaptations to deal with climate change is interest of researchers. Therefore, in this study with purpose of previous trend analysis and prediction of precipitation, mean minimum and maximum temperature were used non-parametric Mann-Kendall test and General Circulation Models, HadCM3, respectively. For this purpose, the output data of HadCM3 with three scenarios A1B, A2 and B1 by LARS-WG model were downscale in Semirom region. The results showed that temperature parameters (mean temperature, mean minimum and mean maximum temperature) had increased trend in winter, autumn seasons and annual scale in six studied stations and temperature parameters showed different trend in spring and summer seasons and the annual precipitation is showed negative trend in most of the stations. Also, the results of minimum temperature prediction showed that minimum temperature will generally increase with three scenarios during 21 century and the largest increase in mean minimum temperature compared to the current period is observed in November with more than 0.8 °C increase. The maximum temperature prediction represents a change in the maximum temperature threshold and warming this century in all months of the year, except January and precipitation will increase in all months except June and September using all three scenarios.

Nowadays, the status of water and soil resources is in a critical situation due to its excessive uses. Watershed management practices has been implemented in the field of natural resources to control and combat of these risks that are expected to provide the required performance for the expected time in the project. This research was done in Boodejan basin in Dehaghan of Esfahan province and its purpose was to assess the mechanical stability of structures were constructed at selected river basins. At first, field visits were conducted in the region and the structural characteristics and damages caused by them were registered and the relation between runoff and flood of basin were assessed with different returns period. Based on this evaluation, there were no degradation in two Lace-rock dams and scouring and the poor enforcement structures have been the demolition factors of structures in 39 stone and mortar dams with 34% and 17%, respectively. Due to the low lifetime of the structures, the signs of damage observed in them indicate the beginning of the destruction. If they are not repaired, they will face the problem in the future. In addition, the analysis the one of the topic structures showed that sliding, overturning and piping phenomena have not been observed based on maximum discharge and there was only possible the structural over stressing in the bed that may be due to its weight for over design.

Determination of indices is one of the basic and important steps in the study of wet and drought in each area. Indices can be evaluating the severity and duration of drought, and then the effect of them is determined on the water resources of the area. In this study, meteorological indices (Root Mean Square Error, Percent of Normal Precipitation Index, Rainfall Anomaly Index, Standardized Precipitation Index, DI, PNPI, and SIAP) was calculated using data of eight synoptic stations. The names of the stations are Meime, Varzane, Esfahan, Daran, Koohrang, Shahrekord and Shahreza in Zayandehroud watershed. Then for determine of the most suitable index in Zayandehroud watershed, meteorological drought indices using the minimum of precipitation and correlation methods were evaluated. The results of meteorological drought indices showed that the percentage of drought is different using different indices, as the RAI, DI, BMDI, SPI, SIAP showed that 35 to 45, 30, 20 to 40, 15 to 25, 25 to 35 percent of studied years are drought, respectively. RAI, BMDI, SPI and SIAP showed the highest percentage of occurrence of drought in Shahreza, Varzane, Abadeh and Varzane, respectively. DI index had equal percent of drought in all station except for Daran and Kuhrang stations. Finally, by the attitude of the two methods at the same time, was determined that meteorological drought of RAI and SIAP are better Indices than other drought indices.

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 Ab-Barik watershed in Bam is a part of Lut desert basin. It is like all other desert areas which has erosion problems caused by wind erosion, sand and soil storms. The result of these sand storms appears as continuous and isolated sand hills. In this paper it was attempted to identify direction and source of harvest points by using sedimentological methods. This was accomplished by step by step sand processed method. At the first step the main direction of harvest areas was determined by some studies such as collecting public information, the study of general morphology and measuring sand hill, comparison of aerial photos in different periods and analysis of region winds. At the second step the origin of sand areas was recognized by investigations such as the study of geomorphological facies of lands of harvest regions with emphasis on morphodynamic wind, granulation of sand hills elements and surface soil of erosionic facies plots at harvest lands, study of morphoscopy of forming particles of samples and determination of indices including central diameter, roundness, sorting and mineralogy of samples. The results revealed that the main source of sands is clay pan facies and farm lands, especially waste lands. Also, the main direction of harvest areas displacement is from south, southwest to north, and northeast. Application of results of this study can modify the used management methods, controlling and confronting with the problem of wind erosion and sand and soil storms.

Range management plans (RMPs) are one of the main tools for the management and utilization of rangelands in Iran. Range size, number of animal units, and rangeland users are considered as the most important factors influencing RMPs. This study was conducted in the rangelands of Isfahan province in 2008 in order to study the relationship between range size, the ratio of permitted animal unit to existing animal unit and number of rangeland users with range condition. Accordingly, the list of RMPs was prepared. Then, the range size, the number of permitted and existing animal units and rangeland users were determined. After that, the range condition was determined using four-factor (winter rangelands) and six-factor methods (summer rangelands). Finally, the relationship between range size, the ratio of the permitted animal unit to the existing animal unit and number of rangeland users (separately and commonly) with range condition was verified by using spearman correlation and discriminate analysis. Results indicated that there was a significant relationship between range size (P≤ 0.01) and the ratio of the permitted to the existing animal unit (P≤0.05) with range condition in summer rangelands. Therefore, it is concluded that range size and animal unit could be considered as one of the factors affecting rangeland degradation.

The relationship between plant species and climatic factors has always been an important subject in plant ecology and the use of multivariate statistical methods might be effective in detecting the relationship between climatic factors and the distribution of plant species. In the present study, climatic characteristics of Astragalus gossypinus Fisher producing tragacanth stretched in a relatively vast area in Isfahan province (approximatley seven percent of natural habitat of Isfahan province) to shed lights on determinant climatic factors on distribution of this species were investigated. In this study, 56 climatic variables were evaluated in the months of January, March, and July in the annual interval and to reduce the number of variables and determine the most important factors. Factor analysis was applied using principal components analysis. The results showed that four factors, namely cooling temperature-humidity, precipitation-storm, cloudiness, and windiness account for 39.05%, 32.77%, 11.44%, and 8.63%, and totally 91.88% of the variance of the data, respectively. Also, the cooling temperature-humidity factor has the greatest impact on presence of this species, therefor, in areas where this species can be seen, the cooling temperature-humidity factor is positive and vice versa.

This study aimed to identify factors affecting the development of gullies and identify the most effective factor and the impact of each factor on the development of gully and gully development predictive models was defined in some regions of Kerman province. At first، 11 gullies in the regions of Baft، Rayen and Rabor are selected and the annual rainfall، width، length، slope bottom of gully، slope of area، the drainage area of gully، soil texture، pH، EC and silicate minerals were measured from the soil layers in the forehead gullies each year. Information obtained for both linear and volumetric expansion mode was analyzed by the SPSS11 software and statistical method regression. It was clear that soil salinity، silt soil، the average width of the gully، gully and slope of the watershed area have the greatest impact on the development of gullies in these areas. Also models showed that the affected factors on gullies development are surface runoff and erosion of soil that have generally occurred because of the effect of land use changes.

The geographical location of Isfahan province has led the province to be at risk of drought. One of the ways to mitigate drought is evaluation and monitoring of drought based on indices that can determine its intensity and permanence in each region. In this research, for drought and trend analysis standard precipitation index and Mann-Kendall test were used, respectively. Also, monthly precipitation time series of Isfahan province was applied to forecast drought from 1970 to 2009. For this purpose, Box and Jenkins modeling approach (1976) was used which has three main steps, namely model identification, parameter estimation, goodness of fit test or time independency and normal test of residual. The results showed that most of the stations in Isfahan province were faced with severe drought in the year 2000 and this situation was repeated one more time in 2008. Also, the results brought forth multiplicative models in all the stations. ARIMA (1,0,0) (0,1,1) showed the highest correlations between control and forecast data in Isfahan, Meime and Ardestan stations, and the model ARIMA (0,0,1) (0,1,1) displayed the highest correlation between control and forecasted data in Naein, Freydoonshahr, Khansar and Natanz. These models were selected as the best models through which the amount of precipitation was predicted till 2015. The trend of forecast data across Isfahan province showed that in most months the trend is not significant.