فهرست مطالب morteza khodagholi

Optimal habitat has a beneficial effect on species survival. In this research, a logistic regression statistical method was used to prepare the potential distribution map of Artemisia aucheri Boiss, in Tehran province, Iran in 2020-2021. The maps of 19 bioclimatic and three physiographic variables with a resolution of 4.9 km under current conditions were prepared. Then, the sampling information in relation to the presence and absence of species and environmental variables was recorded and the relationship between species distribution and environmental factors was determined using logistic regression. Finally, the map of potential distribution of Tehran province was produced. The results of logistic regression model showed that in the current situation, 427057 ha (31% of the province) had a probability of more than 75% presence of this species. The kappa coefficient for evaluating the regression model was 0.86 that is one of the models with good accuracy according to Koch and Smith classification. In order to study the effect of climate change on the geographical distribution of the species, climate bio maps were prepared based on the MRI-ESM2-0 circulation model under two scenarios of 4.5 and 8.5 for 2050. The species under study is currently in the range of 1600 to 2800 m. The results showed that by changing the conditions from a balanced to a pessimistic situation, the area with the presence of more than 75% of the species decreases and the area with the presence of 25-50% increases. Also, results showed that the minimum and maximum altitudes in scenario 4.5 will be changed to 1500 and 2500 m, respectively. While according to scenario 8.5, the presence of this species will be only at above 2500 m. In fact, according to the 8.5 scenario, the species will be migrated to higher altitudes. The results identify climate sensitive areas and possible future shelters of A. aucheri to be used in conservation and rangeland planning.

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.

Wind erosion and dust phenomenon are considered as one of the important processes of land degradation and a serious challenge in Iran. This phenomenon occurs due to the interaction between weather and terrestrial processes. The purpose of this research is to investigate and analyze the trend of temporal and spatial changes in the number of dusty days in Iran and to investigate the role of climate in its spread.

In this research, after receiving hourly and daily statistics of dust events (through 148 synoptic and climatology stations) and parameters of precipitation, evaporation, temperature as key climatic elements (from 171 stations) in 22 provinces located in arid and semi-arid regions of Iran, The spread of dust was investigated and the correlation between climate and dust was determined. After calculating the number of dust days in Iran, the information was called in the GIS environment and a map of the spatial changes of the parameter of the number of dust days in the three decades of 1987-1996, 1997-2006, 2007-2016 was prepared. In the following, the spatial analysis of this parameter and its expansion over three decades were investigated. Next, the climate parameter that had the highest correlation with the number of dusty days was selected and after preparing a map of its spatial changes in the GIS software environment, the spatial compatibility of the desired parameter with the expansion of the number of dusty days was investigated. In the next step, after performing the homogeneity test on the dust occurrences, the partial square regression model was used to determine the contribution of the three mentioned climatic elements as independent variables and the number of dust days as a dependent variable.

The results showed that the number of dusty days and the area of its occurrence have increased in Iran, so that in the last decade under study (2007-2016) compared to the previous two decades, the dustiest event occurred in Iran. This increase has been more intense especially in the western and southwestern regions of the country, which were also affected by extra-local dust events. These dust events have spread to the central regions of the country with greater frequency. The homogeneity test in many provinces showed a common change point (year 2007-2008) in the number of dusty days, which could be related to the beginning of severe droughts and climate changes from this year in Iran. The study of climatic parameters (temperature, precipitation and evaporation) on changes in the number of dust days in Iran showed that during recent years, temperature had the highest significant correlation level (0.58) with the occurrence of dust. The temperature gradient map in the last decade (2007-2016) compared to the previous decade (1997-2006) also showed the increasing trend of temperature, especially in the western and southwestern regions as well as the southeastern regions of Iran. Modeling the effect of climatic parameters of temperature, precipitation and evaporation on the parameter of the number of dusty days showed that the contribution of the studied climatic parameters to the occurrence of dusty days is about 33% and other effects can be related to things such as human factors or soil characteristics, type of vegetation, solar radiation, etc.

In general, the results of examining the trend of changes in the number of dust days and climatic indicators for nearly 3 decades indicate a significant increase in the number of dust days in most parts of Iran and the conditions for this increase have been provided and if the trend of changing these indicators in the coming years is according to the current trend, the risk of environmental problems in the country can be expected to increase.

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.

Identification of habitats and suitable environmental conditions for the presence of various animal and plant species is one of the key issues in ecology and environment modeling. In Iran, Gymnocarpus decander species is the main and most abundant plant of the Baluchi flora, especially in the rangeland areas. Due to its high resistance to harsh environmental conditions and salinity, this species can be useful for rangeland reclamation and restoration. In order to assess potential habitats of G. decander in Sistan and Baluchestan province, Iran, this research was conducted in May 2020 using multivariate statistical methods including factor analysis, clustering and logistic regression. To do so, the map of real habitats of G. decander, was modeled using altitude and 62 climatic variables which were prepared using 24 meteorological stations across the province and neighboring. Climatic variables were reduced to 5 factors using PCA, including temperature, precipitation, radiation, dust and maximum temperature, which accounted for 88.3% of the climate change in the studied region. According to the regression models, the precipitation, temperature and altitude variables were the most significant independent variables (p <0.05) which influence the potential habitats of G. decander in the study area. Also, the study area was divided into 5 groups (G1:G5). The results suggest that models are more accurate in homogeneous groups than in the whole region. The Kappa coefficient and perdition accuracy had the highest and lowest values for G1 (68% and 88%) and G5 (19% and 59%), respectively. The results also showed that currently, 48.2% of the studied region has actual habitats. While the modeling results based on the model of the whole region showed that the potential habitat area of this species was 52.3% and based on the grouping models, it was 53.7%. Therefore, based on differences between actual data and modeling result, 4.8% of potential habitats have no G. decander. Also, results indicate that the G4 region with altitude range between 800-1250 m, growth season mean temperature was about 16 °C and annual precipitation about 170 mm was the main habitat for G. decander in Sistan and Baluchestan. According to the results of this study, G. decander is an endangered species and it is necessary to plan long-term management to preserve and restore its habitats in the arid regions of southeastern Iran.

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.

In recent years, climate change has affected the ecosystem and its inhabitants. Climate change affects various biological aspects of species, so it has become a major concern for the management and protection of biodiversity. One of the important effects of climate change is changes in the range of distribution and distribution of living organisms. Therefore, the study of climate change on the distribution of plant and animal species is necessary. Climate change causes the geographical range of plants to shift. Forecasting the effect of climate change on the distribution of valuable plant species is considered essential in order to protect and evaluate the level of threats and management. he prediction of the geographical distribution of the species in the future requires the collection of information related to the presence of the species at present, environmental variables and the combination of this information with new environmental conditions. Modeling the distribution of species is currently the only tool that can be used to evaluate the amount of changes in the distribution of several species in response to climate change. For this purpose, many methods and models have been developed, predictive modeling of the distribution of plant species, as a prediction of the potential distribution of a plant species. Throughout the landscape, it is defined based on the relationship between the occurrence points of the plant species and the effective environmental variables, and it is based on the hypothesis that environmental factors control the distribution of the plant species. The habitat prediction models determine the suitability of the habitat for the establishment of plant and animal species and help the managers of natural resources to identify the factors that threaten the populations, determine the important factors in conservation planning, and examine the climate change scenarios with less time and cost. Geographical distribution of species, favorable habitats of plant and animal species, etc In this research, the current and future distribution of Bromus tomentellus Boiss species in Chaharmahal and Bakhtiari province under two scenarios RCP4.5 and RCP8.5 for the next three decades was investigated.

First, by using 10 synoptic stations in and adjacent areas of Chaharmahal and Bakhtiari province, the database including precipitation variables, minimum temperature, maximum temperature and average temperature of formation and 19 bio-climates were calculated (Table 1). Also, three physiographic variables, including slope, direction and height, were prepared using a digital elevation model (DEM) with an accuracy of 30 meters. Then, using maps of plant types of Chaharmahal and Bakhtiari province and field visits to the current habitat of the species under investigation, the presence and absence points of the species were determined. Using logistic regression (relationships 1 and 2), the growth behavior of this species at the level of the province was determined and the map was modeled and the relevant equations were calculated in the current conditions. A climate for 2050 was extracted from the worldclime site and by putting the extracted data into the equations of the current conditions, the future distribution map of the species Bromus tomentellus for the next three decades by the general circulation model MRI-ESM2-0 under two scenarios RCP4.5 and RCP8.5 was prepared in ArcGIS 10.5 software. The resulting map of the model contains the values of the probability of the presence of the species between zero and one for the desired habitat, which was evaluated using the kappa coefficient for the accuracy of the output map.

Species distribution prediction models can predict potentially favorable habitats for species distribution, therefore they play an important role in determining areas prone to pasture restoration (Pajehan, 2019). It is expected that the forecasting model in the present study will be effective for future protective strategies. In this research, the current range and potential future range of Bromus tomentellus species and for the next three decades (year 2050), under two climate warning models, a milder scenario and a more severe scenario (Rcp4.5 and Rcp8.5) using the model Logistic regression was predicted within the boundaries of Chaharmahal and Bakhtiari provinces located in central Zagros. The results showed that the spatial position of the target species in 2050 with the Rcp4.5 (balanced) scenario is almost the same as the current one. In the Rcp8.5 (pessimistic) scenario, the optimal habitat size of the selected plant will be reduced by 75-100%. Instead, in In some high areas, we will witness the appearance of habitats prone to the occurrence of species, and these areas will be suitable in terms of climatic conditions. So that this species can be seen in areas with an altitude of 2000 to 3200 meters, but in balanced conditions under the Rcp4.5 scenario, it changes its location to an altitude of 3350-2180 meters and in pessimistic conditions under the Rcp8.5 scenario to an altitude of 2400-3600 meters. Therefore, in the balanced and pessimistic scenario, 180 and 400 meters respectively, the habitat of this species will be moved to a higher altitude. In general, climate change and the consequent increase in temperature indices have caused the vertical expansion of Bromus tomentellus and its movement to higher latitudes along the altitude gradient. The results of Sanghoni (2016) also show that by 2080, more than 50% of the habitat area of Bromus tomentellus species will be reduced and it will migrate to higher altitudes. The results of the research on the mountain celery species in the Faridun Shahr area in the west of Isfahan province show that this species migrates to higher areas due to climate change and the habitat of this species will decrease by 80% in 2080. (Abolmaali et al. 2018) Also, the results of the habitat prediction map showed that as the temperature indices increase, the suitability of the habitat for the presence of the species will decrease in the future. Thuiller (2007) stated that on average, every 1ºc increase in temperature causes species of the northern hemisphere to move 160 kilometers towards The pole or 160 meters will be towards the heights. Of course, he said that the changes in different ecosystems are not the same and each ecosystem should be investigated with appropriate methods. As species move towards the poles or higher altitudes, they may disappear or become confined to a refuge away from others, while other species may expand their range.In general, plant vegetation range models are useful and cost-effective tools for the use of natural resource managers and increase their awareness of the effects of climate change on species. The maps obtained from the models show the areas sensitive to climate change and the possible shelters of the selected species in the future for use in the protection and grazing plans of these areas. Progress in understanding species distribution models against climate change and modification of the spatial database can lead to the development of conservation strategies. which is useful for the ecosystem and the species. The maps obtained from the present research can be used in vegetation protection and revitalization programs. Since globally, they want to preserve biodiversity in the central Zagros and it is very important from an ecological point of view and biodiversity Therefore, the predicted potential distribution for the studied species in the central Zagros area provides valuable information for identifying suitable cultivation sites and also for managing the species in the future.

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.

Climate change has been a serious issue in the last two decades, and many studies have focused on its various aspects. In the present study, the effect of climate change on the distribution of Bromus tomentellus was investigated. To do this, 19 bioclimatic variables and three physiographic variables and logistic regression model were used to quantify climate change in 2050 and to study its effects on the change of B.tomentellus species. First, using 17 synoptic stations in and near the province, a database of precipitation variables, night temperature, daily temperature and average temperature was formed and 19 climatic measures were calculated. Also using the digital model of height, with an accuracy of 30 meters; physiographic variables of slope, direction and height were prepared. Then, the presence and absence points of the species were determined and using logistic regression, its vegetative behavior was determined and the modeled map and related equations in the current conditions were calculated. Using current equations and inserting data extracted from the Worldclime database; the future distribution map for 2050 was generated under RCP4.5 and RCP8.5 climate scenarios. The results showed; the average annual temperature (BIO1), the annual temperature range (BIO7) and the average temperature of the coldest season (BIO11) are the most important for habitat fit, the values of which increase with increasing climatic conditions. Average annual temperature in places with a probability of more than 75%; over the next three decades, it will rise by 1.6 to 1.2 degrees Celsius.

Detection of climate parameters indicates that climate change has begun in Iran and it is necessary to identify the potential habitat of the indicator species, present and future years, under climate warning models. In this regard, it should be examined whether the increase in incident temperature in the country, will have a positive effect on the presence of species in the habitats of the distribution site, or a negative effect? For this purpose, the current and future range of Stipa barbata species for the next three decades (year-2050) was predicted under two climate warning models (scenario RCP4.5 and RCP8.5) using the logistic regression model. Output maps, with probability of occurrence between zero and one, to four categories 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), were grouped. Finally, based on the coefficients of the variables in regression relationships, effective variables for the current and future range of S. barbata species were introduced. Based on the results; only temperature-related indices (BIO7 and BIO10) were found to be effective on the distribution of S. barbata species, present and future. The values of the indices increase with increasing climatic conditions. As a result, the range of S. barbata species decreases in response to climate change. This indicates during the next three decades, the presence of S. barbata species will decrease in the habitats of the region and there is a risk of its removal from the ecosystems of the region. In total, climate change and consequently increase in temperature characteristics causing the vertical spresd of S. barbata species, and it will move towards higher latitudes along the altitude gradient of the region.

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.

The detection of changes in climate parameters indicates that climate change has begun in Iran and it is necessary to identify the habitats of potential species, present and future years, under climate warning models. In this regard, it should be examined whether the increase in temperature in the country will have a positive effect on the presence of species in rangeland habitats, or a negative effect?. For this purpose, the current and potential future range of Artemisia Aucheri for the next three decades (2050) were predicted under two climate warning models (Rcp4.5 and Rcp8.5).

In this connection; First, the event map (presence and absence) of A. Aucheri species was prepared at the level of rangeland habitats. Then, the values of predictive environmental variables were calculated at the species occurrence site. For this purpose, 19 bioclimatic variables and three physiographic variables (slope, direction, height) with a pixel size of 4.9× 4.9 km were used to model the distribution. The points of presence were marked with the number one and the absence with the number zero. Then, considering the values of each of the climatic and physiographic variables as independent variables and the amount of presence and absence of the species as a dependent variable; a regression relationship between species occurrence and environmental variables was calculated. In the next step; based on the resulting regression relationship, prediction maps of the current (present) range and the potential future range of A. Aucheri species for the next three decades (2050) were prepared. In this regard, data related to monthly temperature and precipitation for the base time period (current) and the future time period, with a resolution of 30 seconds, in small scale from the WorldClim.org database, under two climate warning models (milder scenario and The more severe scenario) (Rcp4.5 and Rcp8.5) was downloaded from the General Atmospheric Circulation Model (CCSM4) and the maps were modified using temperature and rainfall data from synoptic meteorological stations. Then, by modifying the temperature and rainfall layers, layers of 19 bioclimatic variables were generated in DIVA-GIS software. From the digital elevation model map in the GIS environment, slope percentage and slope direction maps were generated and used as physiographic variables. All peripheral layers were standardized in Arc-GIS software in terms of area, number of pixels and image system. Next, the calculated environmental variables were placed in the regression relationship presented in the previous step, which was obtained between species occurrence with climatic and physiographic variables. Then, in the context of the Biomod package in the R program; the statistical model was transformed into a species distribution map, and in accordance with the fitted values, in Arc GIS software, a map was generated with a value between zero and one, and values close to one indicate areas with high probability of occurrence of the species. To better map the current range and future potential range; output maps, with a probability of occurrence between zero and one, to four floors; Inadequate habitat (0-0.25), almost suitable habitat (0.25-0.5), highly suitable habitat (0.5-0.75) and very high fitness habitat (0.75-1), The grouping was intense and by referring to the coefficients of variables in regression relations, effective variables for the current range and potential future range were introduced. In this regard, the extent of conformity of the presence range of A. Aucheri species with the current range (present) and their potential range in the future was evaluated using kappa statistical coefficient.

Global warming due to increased greenhouse gas emissions; it has caused obvious changes in Iran's climate, including rising temperatures, increasing climatic hazards and decreasing rainfall, in the last two decades. In this regard, most scientific sources emphasize that the increase in temperature has reduced the coefficient of bioclimatic comfort, and some plant and animal species that are not able to adapt to climate change, they migrate from their permanent habitat or gradually disappear. In this study, this aspect of the issue, namely climate change and the distribution of plant species, was emphasized. Based on the results; among the climatic and topographic variables, only the temperature-related indicators, in order of importance, include; BIO9, BIO10, BIO5 and BIO1 were identified as effective on the distribution of A. Aucheri species. The values of the characteristics increase as the climatic conditions worsen and as a result, the suitable habitat level (more than 75% probability) of A. Aucheri species will decrease for the following decades. In other words, it is shrinking in response to climate change. In this regard, the suitable habitat area of this species (probability of occurrence more than 75%) according to the current forecast map is 274505 hectares, which is about 18% of the total rangeland habitats in the southern Alborz. Also, the suitable habitat area of this species according to the forecast maps for 2050, under two scenarios of Rcp4.5 and Rcp8.5, is 208175 and 131964 hectares, respectively, which has about 13 and 8% of the total rangeland habitats. Overall; the area belonging to the classes in which A. Aucheri is more likely to be present has decreased in 2050 than at present. This indicates that in the future, the presence of A. Aucheri species in the habitats of the region will decrease and the risk of its removal from the ecosystems is evident. In sum, climate change and the consequent increase in temperature characteristics will cause the vertical expansion of A. Aucheri species and its movement towards higher latitudes along the altitude gradient of the region. Hence, the lower (1100 m) and upper (2500 m) expected range of vegetation range and altitude range in which A. Aucheri was observed (3400-1800 m); it will change over the next three decades. In this regard, the expansion of plants to higher altitudes during recent periods, an example of species displacement under the influence of climate change, has been mentioned. Also, one of the most important effects of climate change is the displacement of the geographical area of plant species. Based on the results of the present study and similar studies, by determining the degree of overlap of the current range event with the potential future range (for the next decade) of plant species, according to two climate warning models (milder scenario and more severe scenario); The changes that will occur as a result of climate change over the next decade in the distribution of species can be examined. Also, the results will be applicable in conservation and vegetation restoration programs, and based on the results, it is possible to identify suitable climatically and topographically sites for species conservation and rangeland.

In this study, regarding to the diversity of rangeland services, we tried to explain structure of alpine/subalpine ecosystem habitats using a brief review on current data and determine their dominant vegetation types in Iran. In this regard, different vegetation characteristics were determined using the data of the previous project of “Recognition of ecological zones of Iran”. On the basis of the information of mentioned project, the regions above 2700 m a.s.l., equal to 2.2 m ha were considered as alpine/subalpine vegetation zones. These zones, have been categorized according to their vegetation formations (growth forms and plant genus) and the area occupied by bushes and cushion plants, grasses, forbs and Junipers, respectively. The final report of the project of recognition of ecological zones of Iran, has lack of data for vegetation types of the peak areas, wetlands and meadows. According to diversity in vegetation types and structures, selecting the area above 2700 m a.s.l, is not a valid criteria for the alpine vegetation in the whole country’s area, so, it required a up to date and precise criteria to identify and distinguish this areas within different vegetation zones. Therefore, it need further studies according to challenges and opportunities of these areas, which among them, detailed monitoring and conservation, are the most important plans. The complexity and vulnerability of these ecosystems emphasize the priority of eco-restoration plans for these vegetation zones.

The occurrence of catastrophic floods in March-April 2019 in Lorestan province was a clear example of heavy rains that caused very heavy damage to agricultural, urban, transportation and communications infrastructure.  The purpose of this study is to investigate the March-April 2019 rainfall in the Droud-Borujerd catchment area in terms of statistical, synoptic and dynamic characteristics. In this regard, from the data related to the daily station rainfall in March-April 2019 of Boroujerd and Dorod synoptic stations, NOAA climate Synoptic factor data for the 25th March and 2th April 2019 and upper atmospheric data from the University of Wyoming database for the mentioned days of April 2019. The results of statistical analysis showed that the occurrence of rainfall in April 2019 was one of the heavy rains that in the first wave (25th March) 2019 was 15% of the total annual rainfall and in the second wave (2th April 2019) 20% of the total annual rainfall was recorded. Analysis of synoptic patterns of these heavy rainfall events showed that a similar synoptic pattern produced these two waves of heavy rainfall in the region. On both days, the presence of a strong trough a height of 5500 and 5550 geopotential meters, on the east of the Mediterranean Sea that the western region of Iran located in the front of this trough, lead to heavy rainfall. In these two days, the omega index had reached a significant critical value (-0.2). Moisture injection in the study area was done by the interaction of two cyclonic systems (east of the Mediterranean Sea) and anti-cyclone (on the Gulf of Aden) and the source of moisture supply was the Mediterranean Sea, the Red Sea and the Persian Gulf, respectively. High atmospheric instability indices did not confirm the existence of very severe instability in the region. Moderate instability in the lower levels of the atmosphere, which could not be extended to the upper level (Skew-T diagram), indicated that a global synoptic system was involved in the whole region and no local convection factor played a role.

Artemisia spp. occupy millions of hectares of natural habitats in the country and is considered the largest rangeland ecosystem in Iran. The dependence of various plant and animal communities on these habitats confirms their high capacity, and comprehensive management in these habitats is of utmost importance. Planning in the field of rangeland ecosystem management requires basic information in these areas. According to the results, Artemisia species are distributed in about 34 million hectares of steppe and semi-steppe regions of Iran, covering about 21% of the country's land area. Artemisia sieberi and Artemisia aucheri are the most abundant Artemisia species in Iran. Unfortunately, in recent years, the drying up of Artemisia spp. has been observed in many parts of the country, mainly due to overgrazing and successive droughts. These habitats are very sensitive and fragile due to the harsh habitat conditions. Climate change, overgrazing, and land-use change are very important in determining the fate of these habitats. Artemisia lands classification with grazing management approach is an inappropriate and imposed view and has neglected the real potential of these habitats. However, the results of various studies conducted in these areas show that the average forage production in these ecosystems is very low and about 150 kg/ha. This valuation with the view of forage supply prevents the adoption of an appropriate strategy in the country's livestock system to supply the energy needed by livestock. Therefore, due to the fragility of these ecosystems and the services that these natural areas provide to the country, it is necessary to review their management to use the real potential in preserving biodiversity and protecting water and soil.

The main purpose of this research is to test the agglium of Hormozgan province for the development and development of aloe vera plant cultivars in the base period and the period of change. In this regard, the influential data in the various stages of the aloe vera plant, including the minimum and maximum temperature and precipitation, as climatic agents and height variables, gradients, direction of gradient, soil, as stable elements in the evaluation of aloe vera cultivation areas were used. The multidimensional decision-making technique in the GIS environment was used using fuzzy gamma function for interruption and eventually identifying appropriate arenas for aloe vera plant. The role of climatic changes in two levels of alteration of B1 and A2 was investigated to evaluate changes in Aloe Vera cultivation agriculum in Hormozan province. The results of the implementation of the Fuzzy Gama integration function in Hormozgan province showed that in the base period, 0.35 of the area of ​​the province has good and excellent culture for this plant. These areas are generally consistent with the lowlands of the southern sections of the southern province and are consistent with the soils with tissue and depth and drainage, namely, the arid soils of Sevil and anti-Seville, while in the northern parts of the province, the supply factor, supply The need for an aloe vera plant, tolerance in the year and nightly, the product performance is very weak and the development of aloe vera farms in these areas is not recommended. In the simulated climatic conditions for 2070 under the 2ndretic scenarios, aloe vera arenas will have relatively significant changes compared to the climate of the base period, so that the most variations related to the A2 scenario, in which poorly functional floors are lacking. And moderate culture capabilities have been exposed to an area of ​​30 to 40 percent, while the two floors of the agricultiva capability and good culture capabilities, under the same system, will show an increase of 20 to 40 percent.

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

Background and Objective:

Soil organic carbon in rangeland ecosystems has a variety of functions such as increasing soil fertility, controlling erosion, increasing soil water permeability and, reducing the effects of greenhouse gases. Therefore, it is a key indicator in determining soil health that affects all physical, chemical, and biological properties of soil. The large area of the country's rangelands causes a serious challenge to the use of traditional methods in estimating soil organic carbon. In such situations, the use of remote sensing capabilities can be considered as a suitable option for monitoring the organic carbon of the country's rangeland soils.  The aim of this study was to determine the most important spectral factors affecting topsoil organic carbon in two summer rangelands.

Materials and Methods:

 This research was carried out in two summer rangelands of Lazour and Asaran. The first rangeland (Lazour) with an area of 8150 hectares and an average height of 2875 meters is located in the range of eastern longitudes 52.514 to 52.694 degrees and northern latitudes 35.855 to 35.934 degrees in Tehran province. The second Rangeland (Asaran) with an area of 5642 hectares and an average height of 2465 meters is located in the range of eastern longitudes 53.265 to 53.392 degrees and northern latitudes 35.804 to 35.882 degrees in Semnan province. In this research, the data of the OLI sensor of the Landsat 8 satellite were used. After pre-processing satellite imagery of the studied areas, Top of Atmosphere (TOA) reflectance layers of bands 2 to 7 along with the variables of surface albedo, Clay index, Carbonate index, Grain Size index, NDVI, brightness, greenness, and wetness index of Tasseled cap transformation were calculated. In each of the target areas, using Digital Elevation Model (DEM) maps, the slope, aspect, and hypsometric maps were prepared and by combining the last three layers with each other, a map of homogeneous sampling units was obtained. Soil sampling was performed using the stratified-random sampling pattern. In this way, in each of the homogeneous units, according to its area, several soil samples were randomly taken from a depth of zero to 20 cm and the amount of organic carbon of the samples was measured using the Walkley-Black method.

Results and Discussion:

 The results of this study showed that the spectral variables of Top of Atmosphere (TOA) reflectance layers of bands 2 to 7 along with the variables of surface albedo, Clay index, NDVI, brightness, greenness, and wetness index of Tasseled cap transformation have a significant correlation with topsoil organic carbon (p < 0.01). Also, the results of factor analysis by principal component analysis (PCA) with eigenvalues greater than one showed that the total cumulative variance explained by the 12 variables is 91.74%, which was explained by two factors. The first factor (soil color) explained 76.6% of the variance and the second factor (vegetation and soil texture) explained 15.14% of the variance.

Conclusion:

 The results of this study confirm the existence of a significant relationship between topsoil organic carbon and spectral factors extracted from Landsat 8 OLI sensor data in semi-steppe rangelands. Because of the large area of rangelands in Iran, the use of traditional methods in estimating soil organic carbon is not possible due to the need to spend a lot of time and money. And in such situations, the use of Remote sensing (RS) capabilities can be considered as a suitable option for monitoring the topsoil organic carbon in the rangelands.