جستجوی مقالات مرتبط با کلیدواژه « rangeland » در نشریات گروه « کشاورزی »

Fire is a significant ecological factor that influences rangeland ecosystems, particularly in arid and semi-arid regions, where it plays a crucial role in the growth, development, and evolution of plant species. Historically, controlled burning of vegetation in natural ecosystems has been one of the simplest methods for altering and enhancing habitats, as well as for eliminating pests, diseases, and undesirable plants, while also modifying vegetation cover. Understanding the effects of fire on the characteristics of rangeland vegetation is essential for effective post-fire management. Therefore, this study aims to investigate the impact of fire on specific vegetation characteristics and to analyze vegetation responses to fire, with the goal of improving the management of the Sanandaj rangelands.

For this study, three areas Khalichian, Hasanabad, and Haft Asiab located around Sanandaj and affected by fires one to three years prior were selected. Following field surveys and sampling, the flora of these areas was identified using available resources. Vegetation types were determined through the physiognomic-floristic method. Six sites were established for vegetation sampling, comprising three burned sites and three control sites. Each pair of burned and control sites was matched based on topographic conditions, including elevation, slope percentage, and slope direction, to minimize the effects of environmental gradients and focus on the impact of fire. In each site, two transects (one along the slope and one perpendicular to it) were established, with 15 plots along each transect, resulting in a total of 12 transects and 180 plots. Within each plot, vegetation characteristics such as the percentage of canopy cover of plant species, bare soil, stones and gravel, and litter were estimated. The Shannon-Wiener index was utilized to calculate diversity and evenness, while the Margalef index was used to assess richness. An independent t-test was conducted to compare the mean vegetation characteristics.

The results revealed a significant decrease in the canopy cover of shrubs in the burned sites, accompanied by notable increases in the cover of grasses and both annual and perennial forb plants. Total canopy cover, bare soil percentage, production, and species richness significantly increased in all three areas as a result of fire, while litter significantly decreased. Total rangeland production in the fire-affected sites was significantly higher than in the control sites (P < 0.01), with increases of 26.48%, 26.48%, and 40.14% observed in Khalichian, Hasanabad, and Haft-Asiab, respectively. The difference in the species diversity index (Shannon-Wiener index) was not significant in Khalichian; however, it showed a significant increase in the other areas. Comparisons of the Margalef species richness index indicated that fire enhanced species richness in all three areas, with increases reaching significance at the 1% level. The species evenness index exhibited a significant increase in Hasanabad and Haft-Asiab, but not in Khalichian. An examination of plant composition in the studied areas indicated that fire reduced the prevalence of woody species while promoting an increase in herbaceous plants.

This study concluded that fire generally results in an increase in live vegetation cover, a reduction in litter, and an increase in bare soil. Additionally, fire alters plant composition, favoring herbaceous plants over woody species. Therefore, it is recommended that controlled burning be implemented in grasslands where plant composition has shifted and woody species have proliferated. Such practices should be considered alongside other economic, social, and environmental factors to enhance rangeland conditions.

Forests, encompassing approximately 30% of the Earth's land area, hold significant ecological importance due to their rich biodiversity and the multitude of environmental services they provide. These ecosystems outperform other terrestrial habitats, making them invaluable to all life forms on our planet. The destruction of forest habitats and changes in land use patterns exert significant impacts on the variability of soil quality indicators. The consequence of forest degradation encompass various adverse consequences, including the destruction of wildlife habitats, climate change, global warming, diminishing plant and animal biodiversity, and reduced water conservation capacity. Extensive research has been conducted to investigate soil quality in diverse land uses within temperate regions. However, there is a noticeable scarcity of studies focusing on semi-arid regions. It is imperative to note that a comprehensive and practical assessment of soil condition necessitates the simultaneous measurement of physical, chemical, and biological indicators. Such an integrated approach ensures a thorough and effective evaluation of soil quality. The primary objective of this study was to assess the impact of various land uses, namely natural forest (C. betulus - P. persica), plantation (Q. castaneifolia), garden, rangeland, and agricultural lands (rice), on the physical, chemical, and biological properties of the organic and mineral soil layers. Specifically, the investigation focused on the evaluation of fauna and flora, microbial communities, and enzyme activities. The study was conducted in the semi-arid region of Kajur Nowshahrmourd.

To achieve this objective, contiguous sections of the study area were carefully chosen, ensuring minimal variations in height above sea level, percentage and direction of slope. Subsequently, three slice of one-hectare dimension plots (100 × 100) were selected within each study habitat, with a minimum distance of 600 meters between them. From each one-hectare plot, four leaf litter samples and four soil samples (30 cm × 30 cm, 10 cm depth) were collected and transported to the laboratory for analysis. In total, 12 litter samples and 12 soil samples were collected from each of the habitats. The soil samples were divided into two parts: one part was air-dried and then passed through a 2 mm sieve for subsequent physical and chemical testing, while the other part was stored at 4 degrees Celsius for biological assessments. One-way analysis of variance tests were employed to compare the characteristics of the organic layer and soil among the studied habitats. Furthermore, Duncan's test (P>0.05) was utilized to compare the average parameters that exhibited significant differences among the different habitats.

The findings derived from this investigation underscore the substantial variability in organic layer characteristics across different vegetation types. Natural forests emerged as the most prominent in terms of thickness, nitrogen content, and calcium concentration, whereas agricultural areas exhibited the lowest values. Grassland areas displayed the highest carbon content and carbon-to-nitrogen ratio, while agricultural and natural forest areas demonstrated comparatively lower values. Agricultural lands demonstrated elevated bulk density and sand content, whereas natural forests exhibited the lowest values. Notably, natural forests showcased the highest porosity, aggregate stability, silt percentage, and macro- and micro-aggregate quantities, while agricultural areas presented the lowest values. Chemical analysis of the soil indicated that natural forests recorded the highest values for most chemical characteristics, while agricultural lands displayed the lowest values. Biological attributes generally exhibited the highest levels in natural forests and the lowest levels in agricultural areas. Specifically, the abundance and biomass of epigeic and endogeic fauna did not exhibit significant differences among different land uses during the summer season. Managed forests demonstrated the highest values for moisture content, basal respiration, substrate-induced respiration, and microbial biomass carbon. Conversely, agriculture exhibited the lowest values in these regards. The microbial biomass carbon-to-nitrogen ratio was highest in agricultural areas, while natural forests displayed the lowest value. Natural forests displayed the highest values for most nitrogen transformation characteristics, whereas agricultural areas exhibited the lowest values. Nitrogen nitrification and mineralization showed a decreasing trend across different land uses during the summer and autumn seasons. The type of vegetation cover also significantly influenced the variability of soil ammonium and nitrate levels.

Based on the results obtained from this study, it can be inferred that the preservation and conservation of natural forest cover should be given utmost importance. Additionally, in degraded areas, the establishment of woody vegetation can serve as a viable approach for the restoration of ecosystems with similar ecological conditions. Furthermore, the presence of tree covers, specifically C. betulus and P. persica, is of greater significance compared to rangeland and agricultural land uses in enhancing soil fertility and creating favorable biological conditions. As a result, this research provides valuable insights into the impact of different land uses on the characteristics of the organic and mineral soil layers in mountainous habitats. The information obtained can be instrumental in guiding natural resource managers and offering practical assistance in decision-making processes.

Climate change, characterized by reduced rainfall and increased temperature fluctuations, has led to the transformation of rangelands into desert areas. In recent years, various desertification projects have been implemented in these rangelands, each with multiple effects on local businesses. In this regard, this study aims to investigate the economic and social effects of developing seasonal businesses in the process of desertification of rangelands in Agh-Qala County, Golestan Province. The study population consisted of 122 rangeland users, of which 92 were selected as the sample size based on the Morgan's table using a stratified random sampling method. The research instrument was a researcher-developed questionnaire, and the content validity of the questionnaire was examined through obtaining the opinions of experts and board members of the cooperative rangeland management. To assess the reliability of the measurement tool, Cronbach's alpha coefficient was calculated, yielding an average of 0.851. The results of the study indicated that the economic and social effects of developing seasonal businesses in the process of desertification were high. The findings showed that "empowerment in participation and social cohesion" and "diversification of livelihoods" had the highest average rank, indicating the greatest social and economic impact of the seasonal businesses created through the implementation of desertification projects in the study area. Based on the results obtained, targeted employment generation through the introduction of alternative livelihoods to livestock farming and utilizing the existing human potential in the region, especially for women, can increase their motivation for participatory conservation and their level of life satisfaction.

A study of indicator species to manage rangeland ecosystems and preserve the vegetation of natural areas in dry regions is necessary. The knowledge of the ecological requirements of the range species is important for planning and managing plant communities and protecting and exploiting their ecosystems. Golestan province, with its particular geographical position, is the habitat of many plant species. By identifying the factors affecting the growth and adaptation of these species, it is possible to avoid spending money and wasting time planning to improve and restore pastures. One of the valuable genera that grow in rangelands is Artemisia L., which is distributed in arid and semi-arid regions of the country and plays an essential role in soil protection, fodder supply for livestock and medicinal value.

In this study, 12 populations of four species of the genus Artemisia in the rangeland area in the north of Gonbad Kavos in Golestan province, Iran, were studied based on ecological, micro-morphological, and molecular evidence. The ecological studies were carried out using climate data and soil characteristics of the species' habitat. Also, the morphology of the species' pollen grain was investigated using a scanning electron microscope (SEM). The molecular relationships of four species (A. annua, A. sieberi, A. aucheri, and A. fragrans) were investigated using nuclear nrDNA ITS and chloroplast rpl32-trnL(UAG) sequences and their combinations.

The results of the ecological studies showed that many of the Artemisia species were grown in dry climates and in silty and silty loam soils. EC measurements indicated that the soils of area were saline and had poor organic matter. According to the results, many pollen grains of the species were medium-sized and tricolporate. In all studied species, according to the P/E ratio, the outline of the pollen grains, those seen in the polar view were circular, triangular, and equatorial with an elliptical outline and their exine decorations were echinate. The results of molecular studies indicated that all the species formed a monophyletic group with high support (PP=1.00, ML BS=100, MP BS=100). The combined analysis of data showed more supported relationships than the analyses of a part. The results of the cluster tree showed two separate clades. The annual species A. annua was placed in clade 1 and the rest of the studied species with high support (PP=0.88, ML BS=90, MP BS=94) were placed in clude 2.

The results of current research showed that the ecological, micro-morphological characteristics and molecular data were useful in the distinction between the Artemisia species. Such a study allows us to select suitable and adapted genes for the environment and transfer them to the crop species to produce stress-tolerant cultivars. Artemisia is widely distributed in Iran due to its ecological adaptation and high adaptation intensity in natural conditions. Unfortunately, the change in land use and the transformation of natural areas into agricultural lands have caused to shrink the steppic areas and led to limitation of the species formation and diversity. Examining the kinship relationships between species and the evolution of traits can be used to determine the probability of success in interspecies crosses. Therefore, the obtained information can help maintain and balance the Artemisia habitat.

Microclimates are small areas in a general climate zone that have their own unique climatic conditions. Vegetation is one of the essential factors in the structure and function of terrestrial ecosystems and one of the basic links of the vital chain of water-soil-plants and atmosphere. One of the vegetations that has been cultivated in arid and semi-arid areas and is being developed in some of these areas, is pistachio orchards. This research, with the purpose of investigating the impact of pistachio (Pistachio vera L.) orchards on the vegetation of their adjacent rangelands, was performed in the Roshtkhar region of Razavi Khorasan.

First, three areas of pistachio orchards, as three replicates, that were similar in terms of climatic and physical conditions including topography (elevation and slope), soil characteristics (texture, structure, salinity, and depth of groundwater), and vegetation types, were selected. In each area, a pistachio garden was selected that was adjacent to a rangeland at least up to a distance of 100 meters, and after that was located a pistachio garden, abandoned agricultural land, rangeland, or irrigated agriculture. The percentage of canopy cover was measured along a 100-meter transect with 10 plots of 1 square meter by systematic random sampling method.

Results showed significant difference between the pistachio garden and abandoned agricultural land, rangeland, and irrigated agricultural land. Also, the average canopy cover of rangeland between two pistachio gardens was 58.4% greater than other land uses. The lowest canopy (37.4%) was related to the rangeland located between the pistachio garden and abandoned agricultural land. The highest changes in vegetation canopy were related to the pistachio garden- pistachio garden, with a standard deviation of 26.02. Also, the least changes in vegetation canopy were related to the pistachio garden- rangeland with a standard deviation of 18.14.

The results of this research showed the effect of pistachio orchards on the vegetation cover of the neighboring rangelands. The greatest effect is in the case where a rangeland area is located between two vast pistachio orchards. This effect can be caused by the creation of a microclimate resulting from the vegetation cover of pistachio gardens. The existence of these effects, which are caused by the creation of a microclimate due to the development of vegetation in a dry and desert area, can be considered for other areas under vegetation cover and in urban and industrial land uses

 The growth of the population and the increase in food needs have caused humankind to turn to manipulating nature and converting natural lands into crops, especially rainfed agriculture, to provide the food they need. For various reasons, a large part of these lands is abandoned every year, which causes many changes in the physical and chemical properties of the soil. This research aimed to compare the most important physical and chemical characteristics of soil in two land uses, including rangeland and abandoned rainfed in Kurdistan province.

 This research was carried out in Kurdistan province. For this purpose, four regions, including Kilak, Salavat Abad, Sarab Qamish, and Mamukh, were selected in Sanandaj city. In each region, two neighboring rangelands and abandoned drylands were selected. Three 100-meter transects were established in each land use by random-systematic method, and soil samples were collected from 0-30 cm depth. Depending on the conditions and area of the region, 20 composite samples were taken in Kilak, 20 Salavat Abad, 14 Sarab Qamish, and 8 Mamukh. Half of the samples were collected in rangeland, and the other half in abandoned dryland. In the laboratory, soil physical and chemical factors, including acidity, electrical conductivity, absorbable potassium, percentage of soil organic carbon, total nitrogen, available phosphorus, soil texture, and bulk density, were measured by usual laboratory methods. A factorial experiment was conducted using a completely randomized design to analyze the data. The Duncan test was used to compare the means.

 The results showed no significant difference in the percentage of clay, silt, sand, and specific mass in the comparison of rangelands in four regions, the comparison of abandoned dryland in the four regions, and the comparison of abandoned dryland in each region. The comparison of the average acidity of abandoned rangeland and dryland did not show any significant difference in any region. Electrical conductivity in Kilak, Salavat Abad, and Sarab Qamish areas was higher than in dryland. However, only in Kilak was there a statistically significant difference. The electrical conductivity of rangeland soil was 143; in abandoned wetlands, it was 109.The comparison of abandoned rangelands and drylands in terms of total nitrogen and carbon numerical values showed that rangelands were more than abandoned drylands in all areas. This meant that nitrogen was 24%, 40%, and 42.8% higher in the Kilak, Sarab Qamish, and Mamukh regions. And statistically, their difference was significant. Also, the carbon difference between the rangeland and the dryland in Mamukh was statistically significant (1.47% in the rangeland and 0.74% in the dryland). There was a significant difference in the amount of phosphorus between the rangeland, 94 mg/kg, and the abandoned dryland, with 234 mg/kg only in the Mamukh region. Only in the Sarab Qamish area was soil potassium higher than in the rangeland by 24.7% in the abandoned dryland.Comparing rangelands and abandoned drylands in terms of the numerical amount of total nitrogen and carbon, it can be concluded that in all areas, the rangeland was more than the abandoned drylands, so that nitrogen in Kilak, Sarab-Qamish and Mamukh regions was 24, 40, respectively, and 42.8% more, their difference was statistically significant and also the carbon difference in Mamukh was statistically significant (rangeland 1.47% and dryland 0.74%). There was a significant difference in phosphorus between rangeland, 94 mg/kg, and abandoned dryland, 234 mg/kg only in the Mamukh area. There was a significant increase in soil potassium in abandoned drylands by 24.7% over rangeland soil in the Sarab-Qamish region.

 This research indicates that the change of land use from rangeland to dryland and then abandonment will change the soil's physical and chemical properties. After about 40 years since the drylands were abandoned, there has been an improvement in most of the physical and chemical factors investigated in this research. In this research, 40 years have been considered. It is suggested to consider different periods in the secondary sequence in future research. This will enable us to determine more precisely when the soil can improve. Also, similar research should be done in other ecological regions with different conditions so that the effect of climatic and topographical factors can be clearly defined.

 Dealing with rangeland degradation factors and rehabilitating these resources are fundamental and necessary steps toward sustainable development. So, decisions and protection programs can reduce land use change and tenure. In this regard, the present study has excavated and analyzed strategies to prevent land use change and tenure of rangelands from the perspective of experts in Gonbad Kavous city of Golestan province.

This research is a descriptive-survey type in which the statistical population consists of 45 judges, experts, and conservation guards in the city. Forty individuals were randomly selected as a sample size based on the Krejcie Morgan table. The data collection tool was a researcher-made questionnaire. Through five focus group interviews, we obtained items related to it. So that after removing the common and unrelated items, 25 items were summarized as protection solutions from the rangelands of the city. Based on that, a questionnaire was prepared and distributed. Each of the specified items was evaluated on a five-point Likert scale. The questionnaire validity was assessed using natural resources experts' opinions. The reliability was determined by calculating Cronbach's alpha coefficient, equal to 0.81. After collecting and analyzing the data, the mean and standard deviation were used to describe and prioritize the items in the SPSS25 software environment. An exploratory factor analysis technique was used to examine the internal correlation and categorize the protection strategies of land use change and rangeland tenure in the form of several strategies and to determine the amount of variance explained by each. After collecting and categorizing the data, descriptive and inferential statistics were used in the SPSS25 software environment.

 According to the results obtained from factor analysis, the values of KMO and Bartlett were respectively equal to 0.806 and 967.830, significant at 99% confidence. This indicated the appropriateness of the variables' correlation in the analysis. Based on this, five strategies were extracted that explained 71.74% of the total variance of the variables. The educational-cultural solution to preventing land use and land tenure change in the study area was ranked the highest, and the legal-control solution was ranked the lowest in importance. The results indicate that the items "culturalization and information in crime prevention" from the educational-cultural strategy, "creating job opportunities, empowerment and alternative sources of income for local communities and pastoralists" from the strategy support-service, "privatization of rangeland and handing it over to qualified pastoralists" from the management solution, "correct implementation of laws by executive organizations" from the legal-control solution and "using the potential of mobilizing local communities and their participation in rangeland conservation" from the collaborative approach, with the highest amount of factor load, had the greatest impact in different protection strategies on preventing rangeland tenure. The sample t-test results showed that the most effective strategy in preventing land use change and rangeland acquisitions was related to educational-cultural, and the least effective was related to participatory.

 According to the research results, the focus is on culture and information using advancing communication technologies and social networks, monitoring and evaluating pastoralists, and creating a control process to neutralize crime in rangelands. This is proposed as the most effective prevention strategy. Developing a two-way comprehensive program, one side of which is related to government support and services, and the other side is related to the mobilization of local communities and their participation in the activities of conservation, restoration, improvement, and fundamental exploitation of rangelands, can be another recommendation to reduce rangelands degradation.

Social and economic studies are important in investigating rangeland destruction. Investigating the role of social and economic issues in rangeland destruction can reduce destruction in this ecosystem. For this reason, this research has been done to identify the most important socioeconomic factors affecting rangeland destruction in the Niyuk region and prioritize the mentioned criteria using an Analytical Hierarchical process to provide complete information about the causes of rangeland destruction in the region. Considering that no research has been done in this area so far, it increases the necessity of conducting the present research.

Niuk area is located in Yazd province according to country divisions. In this research, first, by studying the sources and consulting with the relevant experts, the most important socioeconomic criteria involved in the destruction of rangelands in the area were determined, and a questionnaire was designed to score and calculate the weight and priority of these criteria. Enough experts completed it. The region's socioeconomic indicators, criteria, and sub-criteria were identified using experts' opinions and research records, and a hierarchical structure was formed. The main criteria include economic and social indicators. Economic indicators are divided into three sub-criteria: livestock and animal husbandry, cutting and harvesting, and change of land use and plans.The sub-criteria considered for the standard of livestock and livestock farming includes a large number of livestock, indiscriminate grazing of rangelands, type of livestock, change of livestock farming method from traditional to industrial, non-observance of livestock entry and exit time, improper distribution of livestock in the rangelands and improper grazing system. Three main sub-criteria of population, poverty, and institutional factors were identified for social indicators. Three main criteria and 14 sub-criteria were identified for social indicators.

A paired comparison between economic and social indicators showed that economic indicators weighing 0.667 have the priority in destroying rangelands. Social indicators with a weight of 0.333 have second priority. Among the main criteria examined by economic indicators, the sub-criterion of change of use and plans with a weight of 0.683 has been allocated the most. It is below the livestock and animal husbandry standard with a 0.200 weight. It was ranked third for cut and harvest with a 0.177 weight.Among the main criteria of social indicators, the criterion of institutional factors with a weight of 0.637 is the priority, and the factors of poverty and population are in the next ranks with weights of 0.258 and 0.105. The results showed that the sub-criteria of converting rangelands into mines, building access roads to mines, and political interference in natural resources were ranked first to third with weights of 0.176, 0.083, and 0.082. The first two sub-criteria of economic indicators and the third criterion of social indicators are the destruction of rangelands in the Newek region. The sub-criteria of literacy status and age composition of the population with weights of 0.004 and 0.003 were placed in the last priority. These sub-criteria were related to social indicators.

It can be concluded that the most important factors of the region's destruction are the change of land use and conversion of rangelands to mines, construction of access roads to mines, institutional factors and interference with natural resources, and lack of integrated management of natural resources. To prevent the destruction of rangelands in the region, it is necessary to minimize the construction of any mines and communication ways related to mines, and it is suggested that considering the activity of mines, the customary rights of pastoralists should be considered and the participation of ranchers in decision-making should be expanded to maximize the possibility of the success of projects with the support of stakeholders.

Drought phenomenon stands as one of the most significant challenges of the contemporary era, exerting its influence on all ecosystems, including rangelands, at both global and regional scales. The heightened vulnerability of pastoralists underscores the necessity of embracing the concept of resilience. This research aims to investigate existing studies on the resilience of pastoralists under drought conditions and to propose a comprehensive model. A systematic review methodology was employed in this study. The findings of relevant domestic and international research were systematically analyzed using the seven-stage method of Sandelowski and Barroso. Based on inclusion and exclusion criteria, 30 studies were examined. The Waltz and Bausell method was employed to assess the validity of the extracted data. The reliability was also assessed through the Kappa coefficient, yielding a value of 0.87, indicating excellent agreement. The research results led to the formulation of a comprehensive model comprising seven factors: economic, social, individual, institutional, physical, educational-promotional, and ecological. Among these factors, the economic factor emerged as one of the most influential. The resultant model, identifying the factors that impact the resilience of pastoralists under drought conditions, provides the potential for enhancing crisis management, reducing vulnerability, and establishing the necessary groundwork for nationwide rangeland planning.

Arbuscular mycorrhizal fungi, due to their very beneficial effects in the growth and development of plants through supplying the water needed by plants, especially in drought stress conditions and increasing their tolerance to salt stress and in general, helping the plant to overcome living and non-living tensions, they are the focus of many researchers. This research was conducted during 2020-2022 with the aim of investigating the effect of flood spreading, vegetation type on the abundance and diversity of mycorrhizal fungi in Kowsar Station.

In spring and autumn, in different land covers, including planted Eucalyptus and Acacia forest, planted pasture with Atriplex bushes with 37 years old and natural pasture in two situations with flood spate irrigation and without spate irrigation. Three samples were prepared from roots less than 1 mm of trees and dominant plants (Heliantemum, Dendrostellera, and Artemisia) in the pasture and the rhizosphere soil up to a depth of 20 cm. After separating and staining the roots, their microscopic examination to determine the presence of symbiosis in the root tissue and to determine the extent of root colonization with mycorrhizal fungi and the extent of mycorrhizal symbiosis based on the extent of root contamination with structures of mycorrhiza was done. The soil passed through a 2 mm sieve was used to separate the spores, and the genus and species of mycorrhizal fungi were identified based on the morphology of the spores using identification keys and information available in scientific sources.

The results showed that the spore density of mycorrhizal fungi in both sampling seasons was higher in areas with flood spreading than areas without flood spreading. The highest spore density in the field of flood spreading in the autumn season is related to H. lippii with the number of spores 50.20 per gram of soil and the lowest with the number of spores 18.80 per gram of soil related to this species in the field without flood spreading in spring. So that the difference between the two was statistically significant with Duncan's test at the 5% level. Also, in all land uses, spore density was higher in autumn than in spring. The highest percentage of root colonization or the percentage of symbiosis was related to Acacia with 61.81% in the field without flood spreading in spring season and the lowest value was related to Eucalyptus with 12.26% in the field without flood spreading in autumn season. In this research, 21 species belonging to 9 genera Acaulospora, Claroideoglomus, Diversispora, Entrophospora, Funneliformis, Glomus, Rhizophagus, Scutellospora and Septoglomus were identified in with and without flood spreading areas. Septoglomus constrictum was the most abundant with 100.0% frequency. Glomus heterosporum and Rhizophagus aggregatum were in the second category with a frequency of 50.0% and Funneliformis mosseae, Glomus ambisporum, Glomus intraradices and Rhizophagus fasciculatus were in the third category with a frequency of 33.3%.

Considering the fact that the identification of mycorrhizal fungi in the rhizosphere of tree plants and pasture bushes in dry areas and their use can be a fundamental step to reduce the negative impact of various stresses, including drought stress, it is suggested the active and effective species of these fungi may be identified and propagated and used as inoculum (biofertilizer) to restore rangelands in these areas.

Livestock grazing has a direct or indirect effect on the density, diversity, and distribution of vegetation cover in Rangelands. Excessive livestock grazing is one of the destructive pressures on rangelands, which causes a decrease in diversity, and loss of sensitive plant elements. In this regard, maintaining species diversity and abundance is one of the goals of managing natural ecosystems. The concept of species diversity is a combination of two interconnected components of richness and uniformity. Species richness means the number of species per unit area and uniformity means the distribution of individuals and plant species per unit area. Many species diversity indices have been invented so that species diversity can be studied using them. Considering the importance and role of both components of species diversity, ecologists want to evaluate and study indicators that examine both components and determine the contribution of each. In this regard, several methods have been proposed for the evaluation and studies of plant diversity. Two major groups of these methods include numerical indices (richness, uniformity, and diversity) and parametric indices (for example, frequency distribution models, category-frequency diagrams, dominance-diversity, and diversity grading curves). In this research, the condition of vegetation cover, frequency, abundance, and diversity of species in three rangelands with light, medium, and heavy grazing intensities in the rangelands of Sarbisheh City is investigated.
 
This research was carried out in the plain rangelands of west of Sarbisheh City located in South Khorasan Province. First, after the field visit and observing the effects of destruction in the soil and vegetation caused by the intensity of livestock grazing and the presence of invasive plants in the studied rangelands, In the whole field of research, The effects of light, medium and heavy grazing (each in three separate plant types) were observed. Sampling in each plant type was done randomly and systematically. The percentage of plant cover and density was evaluated by visual and counting methods, species abundance based on the Ranquier method, species diversity using numerical indices, and species abundance using statistical and ecological models. Kruskal-Wallis non-parametric test was used to compare vegetation characteristics and species diversity in three intensities of livestock grazing. In order to select the best model for fitting the Four species data with statistical models, akaike's information criterion (AIC) was used.
 
The result of the Kruskal-Wallis non-parametric test showed that the intensity of livestock grazing had no significant effect on any of the studied characteristics. Nevertheless, the rangeland under light grazing had a higher coverage percentage and plant density (42.27 % and 28,000 plants per ha) than the rangeland under medium and heavy grazing. According to the Shannon-Wiener index, very low diversity was assessed in two rangeland with light and medium grazing intensity (H=1.78 and H=1.69, respectively), and low diversity was assessed in the rangeland with heavy grazing intensity (H=2.02). Rangeland with moderate grazing intensity is relatively lower in species diversity (H=1.69 and 1-D=0.66) and higher in richness (15 species) and species dominance (D=0.34). Based on the AIC criterion, the results showed that rangelands with light, medium, and heavy grazing intensity were best fitted with the logarithmic series, lognormal series, and logarithmic series models, respectively. In communities where the sampling volume is large, she recommended three logarithmic, Shannon, and Simpson indices, which have low to moderate sensitivity to plot size and are widely used.
 
The results of the present research showed that species abundance patterns change due to the intensity of livestock grazing. By comparing the results of species abundance models in the current research with other research, it can be said that in areas with high species richness, with increasing grazing pressure (from low to high), the distribution of species abundance changes from the normal log series (representing a stable society) to a geometric or log-normal series (representing an unstable society) But in the present research, because the rangeland has a poor condition in terms of species richness and diversity, species abundance distribution models are not a suitable indicator for distinguishing the three intensities of livestock grazing.

Stachys inflata Benth is a medicinal species widely used among people and industries, and its growth conditions and factors affecting its growth are important for principled management and multi-purpose exploitation of rangelands. This study aimed to investigate the effect of soil and topographical factors on the morphological traits of Stachys inflata Benth in the northern rangelands of West Azerbaijan province, Iran.

Eight rangeland sites in Chaipareh and Khoy counties were selected using a systematic-random method, and 80 plots were established along linear transects. The percentage of canopy cover, length of the flowering stem, length, width, and area of the leaf, length and width of the canopy, height of the plant, depth of rooting, number of main branches, root dry weight, and leaf and stem dry weight were measured. The topographical factors of elevation, slope percentage, and aspect were recorded, and the percentage of bare soil, litter, rock, and gravel was estimated. Soil samples were taken from each site to measure soil parameters. The effects of soil and topographical factors on the morphological traits of Stachys inflata Benth were analyzed using Redundancy Analysis (RDA) and clustering analysis (CA).

The results showed that the functional traits of Stachys inflata Benth are under the combined influence of soil and topographical factors. The amount of sand, electrical conductivity, and cations of the rangelands and less amount of elevation values, exposure of the range to the sun, organic carbon, silt, clay, lime, and acidity were found to be positively correlated with biomass production. The dendrogram related to the classification of traits showed the division of traits into 12 separate clusters based on the similarity of the traits.

The results suggest that Stachys inflata Benth prefers harsher environmental conditions for biomass production, and it can be recommended as a suitable species to increase its abundance in degraded sites. The findings of this study provide valuable information for the management and exploitation of rangelands in the northern region of West Azerbaijan province, Iran.

Rangeland use is the most important land use in Iran, as more than half of the country is categorized in this land use. Regulating the hydrological cycle and flood control are among the regulatory services in rangeland ecosystems. The flood event in late March 2019, which occurred on vast areas of Iran caused severe damages to natural and human resources. This study was conducted to assess the contributing factors to rangeland degradation in Northern Iran, which tries to assess the relationship between these factors and the flood. Thus, by filed visit of rangelands in the flooded areas of Golestan province, the rangeland condition was determined based on the modified four factor method. Landsat satellite images between 2008-2009 and 2018-2019 were used to determine the area of land use changes. Semi-structured interviews with 69 local pastoralists were also conducted to identify the contributing factors to the floods. Results showed that the rangeland condition in different flooded areas are mainly in the very poor to poor category and grazing intensity on these areas is more than 1.3 times the rangeland grazing capacity. Findings of satellite images analysis revealed that rangeland landuse has had a decreasing trend between 2008-2019 in Atrak and Gorganrud basins where 70,000 ha of landuse change is estimated. Result from the semi-structural interviews introduced over grazing and high prices of supplementary feeding are the main factors affecting the degradation of rangelands in the north of Golestan province from pastoral communities’ point of view. We found that 91% of the participants believed rangeland road networks and 76% believed livestock loss were the most affected items in the 2019 flood. Therefore, it is recommended that rangeland conservation, restoration and development planning should become a priority and necessary measure for flood control and management.

One of the important steps in assessing rangeland vegetation is determining the sample size. Adequacy of sample size and its determination is always one of the main concerns of rangeland vegetation analyzer. There are two general methods for determining the sample size in rangeland science: graphic and statistical methods. In this study, the sample size required studying the percentage of vegetation and soil in under grazing and enclosure area, in addition to the Cochran method, the analysis of power and effect size has also been used.

This study was conducted on the habitat of Ammodendron persicum in the rangelands of Zirkouh, South Khorasan province. For sampling, initial sampling was performed with 3 transects and 30 plots of 16 m2. In each plot, the percentage of vegetation was estimated; also 18 samples were taken from the soil depth of 0-30 cm. In this study, in order to perform pre-test and post-test power analysis (80% and 60%) in both groups, parametric and non-parametric statistical tests were performed. For this purpose, to compare the percentage of vegetation and sand in the two areas (under grazing and enclosure), if the data is normal, independent samples t-test and if isn't normal, Wilcoxon test were used. The normality of the data was assessed using the Shapiro-Wilk test and the homogeneity of the variances was assessed using the ratio of variance test. In this study, based on the Cochran's formula, the number of plots required for sampling was determined. To determine the sample size, and the validity of the test from the initial data, power analysis and effect size statistics were used. All statistical tests were performed by R software and psych, lsr, pwr and effectsize packages. 

The results showed that, despite the absence of outliers, vegetation data did not have a normal distribution. Even after the second root conversion, the results of the Shapiro-Wilk normality test still showed that the data in this study was not normal. Therefore, in this study, non-parametric tests were used. The results showed that about 502 plots are needed to measure vegetation by the Cochran method. The Cohen effect size for the student's t test with independent samples was calculated to be about 0.23, which is a small difference between the percentages of vegetation between the two areas. The results of the present study showed that 30 pre-test samples at the levels of 0.01 and 0.05 with test power of 4.31% and 13.95%, respectively, and type II errors in the test were 95.69% and 86.05%, respectively. It indicates that the test power for this number of samples is really low. At the power level of 60% and 80%, with an "average" effect size between 46 to 73 plots for each region was calculated and the number seemed more economical. The results of the soil sampling power analysis showed that the test power was 27.21% and 52.04% at the level of 0.01 and 0.05, respectively, and type II the errors in the test were 72.79% and 47.96%, respectively.

  Finally, it can be said that at least 46 plots and 22 soil samples were required to study this rangeland to an acceptable level. It is suggested that if the null hypothesis is rejected, in addition to the P value, the effect size and test power be reported. According to the results of this study, in this region, the statistical test of the t-test on 30 vegetation samples had an error of about 86 to 96%. Therefore, in areas with high vegetation changes, the use of the Cochrane method and 30 plots is not recommended at all.

This study compared of univariate outlier detection methods among vegetation data in a study of the effect of grazing intensity in the rangelands of arid regions. For this purpose, after measuring the vegetation cover in the rangeland and before the statistical analysis, the presence of outlier data was examined as the assumption of parametric comparison tests. In this study, eight methods including the boxplot and IQR (Tukey method), standard deviation of the mean (three-sigma rule), median absolute deviation (Hampel method), trimmed mean, 1st percentile and 99th percentile, The Chi Square test (χ²), the Grubbs Test (ESD) and the Rosner test (generalized ESD) were used. The results showed that the vegetation cover of rangelands with light and moderate grazing intensity was not normally distributed (Shapiro-Wilk test: p≤0.05). Even deletion of outliers did not lead to a normal distribution, but it resulted in the homogeneity of variances (Levene's test: p≥0.05). The modified Z-score and the Grubbs and Rosner tests (p≥0.05) did not identify outliers from the vegetation cover data. Among the methods evaluated, the boxplot and MAD method, which are not dependent on the mean, are more suitable for the vegetation cover. Therefore, before performing any comparison test, a combination of visual and statistical methods is recommended to evaluate the presence of outliers.