Iranian Journal of Range and Desert Research

Determining soil factors affecting soil organic carbon storage in rangeland and desert habitats of South Khorasan

Rostam Moslempour; Samira Hossein Jafari; Reza Yari

Volume 33, Issue 2 , July 2026, Pages 160-170

Abstract

Extended Abstract Background and objectives: Iran has a high potential in carbon storage due to the large extent of rangelands. Rangeland ecosystems are atmospheric carbon sinks. Soil is an important source of carbon storage and it has been proved that carbon storage in soil is more than three ... Read More Extended Abstract Background and objectives: Iran has a high potential in carbon storage due to the large extent of rangelands. Rangeland ecosystems are atmospheric carbon sinks. Soil is an important source of carbon storage and it has been proved that carbon storage in soil is more than three times the storage in the atmosphere and vegetation. Knowing the amount of soil carbon sequestration and storage can be used as a useful and practical tool to better understand soil carbon cycle. Therefore, the purpose of this research is to investigate and determine the most important soil factors affecting the amount of soil carbon storage in Zirkouh and Ferdows habitats in South Khorasan with different plant types. Methodology: The present research was carried out in South Khorasan province in rangeland habitats of Zirkouh, including Artemisia sieberi, Zygophyllum eurypterum, and Tamarix stricta plant types, and in the desert areas of Ferdows, including Calligonum polygonoides, Seidlitzia rosmarinus, Stipagrostis pennata, and Zygophyllum eurypterum types. 60 squares of 4×4 meters were established in the representative area of each habitat by random-systematic method, and, canopy cover percentage and plant density was estimated in each plot. Then, 10 plants were randomly selected. Soil samples were taken to a depth of 70 cm in the plots, under the canopy cover of the plant. Soil physical and chemical properties were determined in the laboratory. The correlation diagram (Pearson correlation coefficient) between environmental characteristics and carbon storage was drawn. First, ordinary multiple linear regression (OLS) analysis was used to examine the relationships, and the multiple collinearity between environmental characteristics and organic carbon storage was examined by the variance inflation factor (VIF) criterion. Since normality and multiple collinearity are assumptions of ordinary regression, two regression models: Partial Least Squares (PLS) and Principal Component Regression (PCR), were used in the present study. Results: The results of descriptive statistics showed that in Zirkouh habitat, the highest and lowest changes in soil carbon storage are in Tamarix habitat (Mean=20.77, SD=11.66) and Artemisia habitat (Mean=13.83, SD=1.81), respectively. In Ferdows region, the highest and lowest changes in the amount of soil carbon storage were observed in Calligonum (Mean=6.96, SD=1.57) and Zygophyllum (Mean=5.36, SD=0.80) habitats, respectively. In Zirkouh habitat, carbon storage had a significant negative correlation with sand (p≤0.05) and a significant positive correlation with canopy cover percentage, N, P, silt, EC (p≤0.01), lime and K (p≤0.05). Interestingly, sand percentage had a significant negative correlation with all measured soil properties in this diagram. In Ferdows region, carbon storage had a significant negative correlation with gypsum and potassium (p≤0.05) and a significant positive correlation with N. In the present study, two models of partial least square regression (PLS) and principal component regression (PCR) were used. In PLS regression method as the best model, in Zirkouh habitat, the parameters such as sand, silt, phosphorus and canopy cover percentages remained as significant variables in the model and among them, silt percentage had the most impact in predicting carbon storage. In Ferdows habitat, the parameters including organic carbon, silt, nitrogen, potassium and gypsum remained as significant variables in the model. Conclusion: Investigating the effective factors on carbon storage can help managers and decision makers in choosing management methods and modifying existing methods in order to reduce atmospheric carbon density. The results of this research showed that among the two models of partial least square regression (PLS) and principal component regression (PCR), PLS model is the best model to determine the factors affecting carbon storage. There was a positive relationship between vegetation cover and soil nutrients (N, P, K) and carbon storage in the Zirkouh habitat, which emphasizes the role factors related to fertility in carbon storage. By implementing appropriate range management strategies—such as protection, improvement, and restoration of vegetation cover—we can increase soil organic carbon storage. This approach can help prevent air pollution, reduce vegetation degradation, and ultimately mitigate the harmful effects of climate change.

View Article

Technical and Economic Evaluation of Alhagi camelorum Forage Production by Flood Irrigation Method in arid and desert area

Jalal Barkhordari

Volume 33, Issue 2 , July 2026, Pages 171-180

Abstract

AbstractBackground and ObjectivesIn arid and desert regions, due to the irregular spatial and temporal distribution of precipitation, a valuable volume of seasonal floods has become unavailable in the form of evaporation, and on the other hand, the lack of suitable land and irrigation water has created ... Read More AbstractBackground and ObjectivesIn arid and desert regions, due to the irregular spatial and temporal distribution of precipitation, a valuable volume of seasonal floods has become unavailable in the form of evaporation, and on the other hand, the lack of suitable land and irrigation water has created great limitations for the production of livestock fodder. Therefore, the use of creative methods adapted to the natural conditions of the region in utilizing the potential of dry muddy floods of dry rivers in arid regions is essential to solve this problem.MethodologyIn this study, in the Miankouh Flood spreading Station, with the aim of evaluating the effect of flood irrigation and sediments accompanying floods on the production of Alhagi camelorum forage, after providing the technical conditions for the establishment of this plant in terms of uniform flood distribution and no waterlogging, Alhagi camelorum seeds were established and grown along with muddy floods behind the embankments. After establishment The stability of the thorn bushes, the percentage of canopy cover, density and forage production of the thorn bushes were measured using 1x1 square meter plots in 30 plots in three transects parallel to the embankment and 10 plots in the thorn fields on the edge of the project without flood irrigation conditions as a control in three years (1401, 1402 and 1403) were measured and statistically analyzed. Also, samples of the produced forage under flood irrigation and control conditions were prepared according to the standard and analyzed in the laboratory to evaluate the qualitative components. The economic feasibility of the produced forage was also evaluated and analyzed in comparison with common forages using the engineering economics method.ResultsComparison of the survey results showed that the production rate and percentage of canopy cover were significant at the 1% level and the density rate at the 5% level. The forage production rate in the first year of establishment was 1.83 tons per hectare and in the third year after the complete establishment of the bushes and appropriate flooding of the area was 39.7 tons per hectare of dry forage was recorded. Also, comparing the results of the analysis of the quality of the forage produced by the flood irrigation method and the control, a significant increase in crude protein of 14.33% was obtained, which is comparable to common forages such as alfalfa. The benefit-cost ratio in this project has been calculated to be 1/4, which means that for every 1 Rial invested in Alhagi camelorum floodplain agriculture, 1.4 Rials of benefit is generated.ConclusionAs a result, by utilizing the potential of seasonal muddy floods, most of which are usually wasted due to evaporation, and utilizing desert sandy land, it is possible to produce economic fodder with appropriate quantitative and qualitative yield from the drought-resistant species of Alhagi camelorum under flood irrigation conditions in arid and desert areas, similar to the project area.

View Article

Long Term Monitoring of Inundation Dynamics in Namak Lake Using Satellite Imagery in Google Earth Engine

Samaneh Razavizadeh

Volume 33, Issue 2 , July 2026, Pages 181-190

Abstract

Abstract Background and Objectives Lakes and wetlands in arid and semi-arid regions play a crucial role in sustaining ecosystems, regulating local climate, controlling dust storms, and preserving biodiversity. Lake Namak, as one of the major evaporitic–saline basins of the Central Iranian ... Read More Abstract Background and Objectives Lakes and wetlands in arid and semi-arid regions play a crucial role in sustaining ecosystems, regulating local climate, controlling dust storms, and preserving biodiversity. Lake Namak, as one of the major evaporitic–saline basins of the Central Iranian Plateau, has experienced a noticeable decline in surface area and increasing instability in its water coverage over recent decades. Reduced hydrological persistence in this lake can intensify dust emissions and weaken regional ecological functions. Despite its importance, long-term analyses based on continuous satellite time series remain limited. Therefore, the objective of this study is to monitor and analyze the spatiotemporal changes in the inundated area of Lake Namak during 1995–2024 using Landsat imagery and the Google Earth Engine platform. Materials and Methods In this study, Landsat satellite imagery from Landsat 5, Landsat 7, and Landsat 8 acquired between 1995 and 2024 was used. To harmonize data from different sensors and minimize inconsistencies, surface reflectance products were employed, and cloud and cloud-shadow pixels were masked using standard algorithms. All processing and analyses were conducted within Google Earth Engine, enabling access to a long-term satellite archive and efficient data processing. To extract water bodies, the Normalized Difference Water Index (NDWI) was calculated for each image using the green and near-infrared bands. A threshold value was then determined empirically based on comparisons with false-color composites and visual interpretation, and binary water/non-water maps were generated. Water-covered areas were subsequently calculated at monthly, seasonal, annual, and decadal scales. Trend analysis was performed using time-series assessment and linear regression to determine the direction and magnitude of changes over time. Additionally, the non-parametric Sen’s Slope estimator was applied to obtain a more robust estimate of change rates and to reduce the influence of outliers. To evaluate the stability of the lake’s inundation regime, the Transition and Seasonality layers from the JRC Global Surface Water dataset were analyzed within Google Earth Engine. Results Time-series analysis of Landsat imagery revealed a decreasing and unstable trend in the extent of Lake Namak’s inundated area over the past three decades. The mean inundated area in the first decade (1995–2004) was about 154.4 km², decreasing to 48.1 km² in the second decade (2005–2014) and to approximately 41.1 km² in the third decade (2015–2024). Annually, the maximum water extent occurred in 2001 (about 383.6 km²), while the minimum was recorded in 2014 (about 1 km²), indicating strong interannual variability. Trend analysis using linear regression confirmed a significant negative trend, and the negative slope highlighted continuous decline in inundation. Similarly, Sen’s Slope analysis yielded negative annual change rates, indicating a persistent long-term reduction with higher robustness. Seasonal patterns showed that spring exhibited the highest inundation, with about 10% of the lake’s surface containing water, followed by winter with about 5.4%, while summer and autumn displayed minimal inundation. Monthly analysis showed maximum inundation in March, April, and May. The Transition layer indicated that approximately 70.4% of the lake area remained unchanged, while about 15.9% fell into the “new seasonal” class and around 13% into the “seasonal” class, reflecting the expansion of temporary water bodies. Seasonality results showed that more than 71.1% of the lake surface lacked persistent inundation, with most water-covered areas present only one to three months per year. Conclusion The findings indicate that Lake Namak has undergone a substantial reduction in surface area and hydrological persistence over the past three decades, with both linear regression and Sen’s Slope confirming the declining trend. The dominance of short-term and seasonal inundation reflects increasing hydrological instability. Continuation of this trend may lead to major environmental consequences, including increased salinity, intensified evaporation, and expansion of dust-source areas. The use of satellite imagery and Google Earth Engine provides an effective framework for long-term monitoring of such dynamic environments.

View Article

Habitat Prediction of Thymus kotschyanus Based on Environmental Factors Using Logistic Regression and Interpolation (Case Study: Dolanieh Habitat in Piranshahr County)

Somayyeh Souri; Shahryar Dashti; Yousef Ajani; Esmaeil Karimi; Elham Noori

Volume 33, Issue 2 , July 2026, Pages 191-200

Abstract

Abstract Background and Objectives Environmental factors can significantly influence the distribution of plant species. Predicting suitable habitats for species requires a thorough understanding of these influences. Thymus is one of the most important genera in the Lamiaceae family, comprising over ... Read More Abstract Background and Objectives Environmental factors can significantly influence the distribution of plant species. Predicting suitable habitats for species requires a thorough understanding of these influences. Thymus is one of the most important genera in the Lamiaceae family, comprising over 215 species widely distributed across the world, particularly in the Mediterranean region. The present study aims to predict the habitat suitability of Thymus kotschyanus using logistic regression modeling and spatial interpolation methods in the Dolaniyeh region of Piranshahr County. Materials and Methods Topographic variables including elevation, slope, and aspect were derived from the region’s Digital Elevation Model (DEM), while climatic parameters such as average temperature and precipitation were obtained from the Dolanaya synoptic station. A total of 94 presence and absence points of Thymus kotschyanus were systematically and randomly sampled. Binary logistic regression was used in SPSS software to evaluate the relationship between species presence and environmental factors. Spatial variation in habitat suitability was assessed using deterministic and geostatistical interpolation techniques. Results The results indicated that the probability of T. kotschyanus presence had a negative relationship with variables such as latitude, slope aspect, leaf width, soil organic carbon, calcium carbonate, copper, and mean monthly and annual precipitation, as well as sand and clay content. In contrast, variables such as slope, leaf length, plant height, electrical conductivity, pH, zinc, iron, and average temperature showed a positive relationship with the probability of species presence. The likelihood of Thymus presence increases in arid and semi-arid areas with suitable slopes. Spatial distribution mapping revealed that the eastern part of the study area had the highest probability of presence, which gradually decreased toward the southwest. In most parts of the region, the probability of presence was below 0.25, while in a few localized areas, it approached 1.00. ConclusionBased on the results of the regression models, which showed significant effects of environmental variables such as elevation, slope, aspect, and precipitation on the distribution of T. kotschyanus in the study area, these models can serve as effective tools for identifying potential habitats and mapping the species’ geographic range. Considering the increased presence in the eastern region and a notable decline in the southwest, the findings of this study provide a scientific foundation for grazing management strategies and cultivation planning of T. kotschyanus tailored to the ecological capacity of different zones, contributing to the sustainable utilization and conservation of this valuable medicinal species. Abstract Background and Objectives Environmental factors can significantly influence the distribution of plant species. Predicting suitable habitats for species requires a thorough understanding of these influences. Thymus is one of the most important genera in the Lamiaceae family, comprising over 215 species widely distributed across the world, particularly in the Mediterranean region. The present study aims to predict the habitat suitability of Thymus kotschyanus using logistic regression modeling and spatial interpolation methods in the Dolaniyeh region of Piranshahr County. Materials and Methods Topographic variables including elevation, slope, and aspect were derived from the region’s Digital Elevation Model (DEM), while climatic parameters such as average temperature and precipitation were obtained from the Dolanaya synoptic station. A total of 94 presence and absence points of Thymus kotschyanus were systematically and randomly sampled. Binary logistic regression was used in SPSS software to evaluate the relationship between species presence and environmental factors. Spatial variation in habitat suitability was assessed using deterministic and geostatistical interpolation techniques. Results The results indicated that the probability of T. kotschyanus presence had a negative relationship with variables such as latitude, slope aspect, leaf width, soil organic carbon, calcium carbonate, copper, and mean monthly and annual precipitation, as well as sand and clay content. In contrast, variables such as slope, leaf length, plant height, electrical conductivity, pH, zinc, iron, and average temperature showed a positive relationship with the probability of species presence. The likelihood of Thymus presence increases in arid and semi-arid areas with suitable slopes. Spatial distribution mapping revealed that the eastern part of the study area had the highest probability of presence, which gradually decreased toward the southwest. In most parts of the region, the probability of presence was below 0.25, while in a few localized areas, it approached 1.00. ConclusionBased on the results of the regression models, which showed significant effects of environmental variables such as elevation, slope, aspect, and precipitation on the distribution of T. kotschyanus in the study area, these models can serve as effective tools for identifying potential habitats and mapping the species’ geographic range. Considering the increased presence in the eastern region and a notable decline in the southwest, the findings of this study provide a scientific foundation for grazing management strategies and cultivation planning of T. kotschyanus tailored to the ecological capacity of different zones, contributing to the sustainable utilization and conservation of this valuable medicinal species.

View Article

Investigating the Effects of Rural Systems Development and Progress Plan on Social Capital Indicators in Arid Regions (Study Area: Taftan County)

Leila Avazpour; Susan Salajegheh; Mehdi Ghorbani; Hosein Afsharian

Volume 33, Issue 2 , July 2026, Pages 210-220

Abstract

Abstract Background and ObjectiveDevelopment in arid regions faces structural obstacles due to water scarcity, ecological constraints, and social vulnerability. Achieving development in these regions requires the application of scientific approaches to resource management, the use of technologies compatible ... Read More Abstract Background and ObjectiveDevelopment in arid regions faces structural obstacles due to water scarcity, ecological constraints, and social vulnerability. Achieving development in these regions requires the application of scientific approaches to resource management, the use of technologies compatible with arid climates, and the strengthening of participation and social capital of local communities. This research aimed to investigate the effects of the rural development and development plan on social capital indicators in Taftan County, Sistan and Baluchestan province.MethodologyIn order to measure social capital, the indicators of trust and participation among the heads of rural development funds in four villages of Taftan County (Khairabad, Deh Pabid, Kavari, Kale Shahtoot) before (2010) and after the implementation of the Rural Systems Development and Progress Plan (2014) were studied. In this regard, the social network analysis (SNA) approach and indicators such as density, centrality, reciprocity, transitivity, and average geodesic distance have been used. The level of analysis in this study is villages and the unit of analysis is the heads of rural development microfinance funds. The questionnaires required for conducting the research were completed by 74 heads of the funds in the four villages under study, who were selected using the total number method. The required data were collected through surveys and questionnaires and analyzed using UCINET software.ResultsDryland management requires collaboration between different stakeholders, and social capital helps facilitate this collaboration by building strong social networks. The results showed that the implementation of the plan increased trust, participation, and social cohesion, and indicators such as network density, two-way communication, and transitivity increased and the average geodesic distance decreased. The decrease in the average geodesic distance indicated the strengthening of communication and social unity. Therefore, it can be stated that the " Rural Systems Development and Progress Plan " has promoted social and economic interactions and the social system has moved towards cooperative activities. The findings emphasize the importance of strengthening trust, social participation, and structural cohesion to achieve sustainable development.ConclusionIn arid regions where social capital has been weakened by drought and the resulting scarcity of natural resources, implementing development projects can provide the basis for restoring collective participation and strengthening social trust. The research findings show that the development and progress plan for rural systems in the arid region of Taftan, through the establishment of rural development micro-funds by providing group access to financial resources, increases mutual trust and social participation among individuals, and thus has a positive impact on improving social capital indicators. By strengthening infrastructure and increasing public participation, this project has helped rebuild trust, increase participation, and a sense of social belonging in villages, which is a foundation for improving the quality of life, increasing the resilience of communities, and achieving sustainable development in drylands.

Editorial

Investigation of utilizers view on the livestock grazing frequency and intensity in the rangeland (Case Study: Summer rangelands of Kuhdasht)

Volume 26, Issue 3 , September 2019, , Pages 531-542

Abstract

Livestock grazing is one of the most important factors effective on soil and vegetation structure and function. This study aimed to investigate the factors affecting the grazing frequency and intensity in the rangeland in autumn 2015. The statistical population was the heads ... Read More

Measurement of vegetation changes related to soil characteristics and livestock grazing Case study: Badamistan pastures of Tarem, Zanjan province

Volume 31, Issue 4 , January 2025, , Pages 323-346

Abstract

Background and Objectives Growing awareness of environmental issues and sustainable natural resource management require continuous study and monitoring across various timescales and locations. Ecosystems, including rangelands, undergo constant change. Given their ecological significance, economic ... Read More Background and Objectives Growing awareness of environmental issues and sustainable natural resource management require continuous study and monitoring across various timescales and locations. Ecosystems, including rangelands, undergo constant change. Given their ecological significance, economic role, and vulnerability to irreversible alterations, rangeland monitoring is essential for their ongoing assessment. Research Methodology This study monitored changes in vegetation cover and soil indicators over five years at the Dagestan site in Zanjan Province. Field evaluations included plant and soil factors. Plant-related data encompassed canopy cover percentage, litter percentage, species density (where applicable), production, rangeland condition, and trend. Assessments were conducted using established methods, with adequate sampling and proper distribution across different plant communities during both initial evaluation and subsequent monitoring. Soil factors included pH, electrical conductivity, nitrogen, phosphorus, potassium, organic matter content, bulk density, and soil texture. Results Statistical analysis of vegetation changes and their effects on soil indicators under grazing and flooding over the five years revealed significant differences in most parameters. Total canopy cover and rangeland production differed significantly between years and site types (grazed vs. exclosure) at the 1% and 5% probability levels, respectively. The highest vegetation cover (56%) was observed in the grazed area in 2018, while the lowest (30%) occurred in the exclosure in 2021. Peak total production (126 g m<sup>-2</sup>) was recorded in the exclosure in 2018, while the lowest (48.7 g m<sup>-2</sup>) occurred in the exclosure in 2021. Total species density showed no significant differences between years, site types, or their interaction. However, on average, shrub density was higher outside the exclosure, while grass density was higher inside, indicating a significant difference. Vegetation changes due to grazing and flooding affected certain soil parameters. Increased grazing intensity correlated with decreased potassium, phosphorus, nitrogen, organic carbon, and electrical conductivity in the topsoil. Conclusion Over the five-year study period, grazing significantly influenced vegetation, and the decline in vegetation cover had a notable impact on soil physical and chemical properties. Vegetation changes in the study area were gradual and shaped by rangeland management practices. Regular monitoring of qualitative and quantitative changes in rangeland vegetation is essential for informed planning and the implementation of effective management strategies for sustainable rangeland use.

The Study of Drought and Wet Year Assessment models for Stations in Mazandaran province

Volume 16, Issue 1 , December 2009, , Pages 44-54

Abstract

Annual rainfall data related to a 26 year period from a number of Mazandaran climatological stations were employed to analyze and model the precipitation toward a determination of drought as well as wet years. Results indicate the occurrence of different intensity drought phenomenon in all stations. ... Read More

Effect of soil chemical properties on forage quality in dry rangeland in south of Fars province

Volume 22, Issue 2 , August 2015, , Pages 381-391

Abstract

This study was carried out to compare the forage quality parameters (CP, DMD and ADF) in two phenological stages between two regions in south of Fars province. The two regions were located close together, and with the exception of soil characteristics, were similar in terms of other environmental factors. ... Read More

Effective factors on ranges insurance acceptance by exploitations in Golestan province-Kalaleh district

Volume 24, Issue 4 , January 2018, , Pages 829-840

Abstract

Rangeland insurance can be one of the mechanisms to deal with inevitable risks of natural resources and may be the most appropriate strategy to reduce financial losses. Rangeland insurance in rural and tribal communities could be considered as a new phenomenon. In this research, the factors affecting ... Read More

Volume 33 (2026)

Volume 32 (2025)

Volume 31 (2024)

Volume 30 (2023)

Volume 29 (2022)

Volume 28 (2021)

Volume 27 (2020)

Volume 9 (2019)

Volume 8 (2019)

Volume 26 (2019)

Volume 12 (2019)

Volume 10 (2019)

Volume 25 (2018)

Volume 24 (2017)

Volume 23 (2016)

Volume 22 (2015)

Volume 21 (2014)

Volume 20 (2013)

Volume 19 (2013)

Volume 18 (2011)

Volume 17 (2010)

Volume 16 (2009)

Volume 15 (2008)

Volume 14 (2007)

Volume 13 (2006)

Volume 7 (2000)

Volume 6 (1999)

Volume 11 ()

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Indexing and Abstracting

Keywords Cloud