Mohammad Reza Sayadi; Mehdi Ghorbani; Mohammad Jafari; Hamidreza Keshtkar; Leila Avazpour
Abstract
The objective of this paper is to identify the factors affecting the medicinal plant supply chain in the Nadushan region using a Glaser approach. The research method is applied in terms of purpose and qualitative in terms of method based on grounded theory and Glaser approach (emerging approach); and ...
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The objective of this paper is to identify the factors affecting the medicinal plant supply chain in the Nadushan region using a Glaser approach. The research method is applied in terms of purpose and qualitative in terms of method based on grounded theory and Glaser approach (emerging approach); and it is exploratory based on the nature of the data and the use of inductive philosophy. The study population consisted of experienced local people and managers and experts in the field of the medicinal plant supply chain with more than five years of experience. Participants were selected using purposeful sampling and theoretical judgment. The data collection method was fieldwork, and the data collection tool was in-depth and structured interviews with 30 participants, including native farmers (15), researchers and experts (10), and intermediaries (5) in the field. The grounded theory approach was used to analyze the data and identify the key factors affecting the supply chain. The results identified 9 selective codes and 41 core codes. The factors affecting the supply chain include climate and weather, the region's high potential for medicinal plant cultivation, initial budget and capital, storage conditions, institutional support, policy, medicinal plant production and harvesting management, medicinal plant processing management, and the use of healthy practices in productivity. Therefore, ensuring a sustainable and efficient supply chain is crucial for maintaining the quality, availability, and affordability of medicinal plants.
Hassan Yeganeh; Fatemeh Mobarhen; Fatemeh Mehdi Gholian; Sadegh Atashi
Abstract
Prickly pear plays a very important role in arid and semi-arid ecosystems due to its high ability to withstand adverse weather conditions and soil protection. This study aims to investigate some morphological and phytochemical characteristics of different parts of the Opuntia stricta plant in the Neka ...
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Prickly pear plays a very important role in arid and semi-arid ecosystems due to its high ability to withstand adverse weather conditions and soil protection. This study aims to investigate some morphological and phytochemical characteristics of different parts of the Opuntia stricta plant in the Neka and Anbaralum regions. The sampling of different organs was done randomly in 2019. Some characteristics of the plant include fruit and cladode size, vitamin C and acidity, measurement of pectin from skin and fruit flesh, measurement of chlorophyll and carotenoid, anthocyanin of skin and flesh, measurement of soluble solids (TSS) from plant organs using calipers. , spectrophotometer, and refractometer were measured. The results showed that the amount of dry weight of the seed, the amount of electrical conductivity (EC), the number of bases, the number of fruit, and the number of cladodes are significant at the level of 5 and 1%, and the amount of dry weight of the seed in Neka region (1.71 grams) is more than Anbar Alum. 1.3) is warm. Also, the amount of electrical conductivity (EC) in the Neka area (3.78 decisiemens/cm) was measured higher than in Anbaralum (6.34 decisiemens/cm). On the other hand, the number of stems, number of fruits, and number of cladodes per unit area were measured in the Neka region (1.7, 51, 111.16) more than Anbaralum (1.33, 11.03, 36.4). It can be said that climatic conditions have an effect on its growth parameters and fruit production, and the most important factor is access to water.
Farzaneh Parsaie; Ahmad Farrokhian Firouzi; Masoud Davari; Ruhollah Taghizadeh-Mehrjardi
Abstract
Surface soil saturated hydraulic conductivity (Ks), as one of the most important physical properties of soil, plays a key role in the distribution of water and nutrients within the soil environment and holds particular significance in water and soil resource management. This study aimed to digitally ...
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Surface soil saturated hydraulic conductivity (Ks), as one of the most important physical properties of soil, plays a key role in the distribution of water and nutrients within the soil environment and holds particular significance in water and soil resource management. This study aimed to digitally model Ks using machine learning approaches in the Kilanah watershed, located in Kurdistan Province, covering an area of 12,000 hectares. Three machine learning algorithms, including Gradient Boosted Decision Tree (XGBoost), Random Forest (RF), and k-Nearest Neighbors (k-NN), were utilized, incorporating various environmental variables derived from the digital elevation model and Sentinel-2 satellite imagery. These variables included distance from the drainage channel, valley depth, relative slope position, channel base level, brightness index, wind effect index, Normalized Difference Vegetation Index (NDVI), Band 12, greenness index, and surface curvature. Additionally, soil parameters such as organic matter, lime content, bulk density, geometric mean particle diameter, soil texture, and near-soil spectroscopic data (Latent Variable) within the wavelength range of 400–2450 nm were used as proxies for pedogenic factors to model saturated hydraulic conductivity. The results indicated that the XGBoost model exhibited the highest accuracy for predicting Ks, with an R² value of 0.65 and an nRMSE of 0.25, outperforming the other models. Spectral data, topographic variables, and soil parameters, as model inputs, played a significant role in predicting the spatial variability of Ks. The XGBoost model was able to provide highly accurate predictions. The results demonstrated that topographic, physical, and spectral variables influence Ks; organic matter, soil texture, and topographic indices such as slope and relative position had the most substantial impact. The generated maps can be utilized for water and soil resource management and hydrological models.
Ziba Maghsodi; Hamid Reza Matinfar; Seyed Roohollah Mousavi
Abstract
The scale of environmental variables is one of the most important features to consider when selecting data. The aim of this study is to improve the accuracy of digital mapping by selecting the optimal scale for predicting six soil properties, For this purpose, 100 surface soil samples (0-30 cm depth) ...
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The scale of environmental variables is one of the most important features to consider when selecting data. The aim of this study is to improve the accuracy of digital mapping by selecting the optimal scale for predicting six soil properties, For this purpose, 100 surface soil samples (0-30 cm depth) were collected based on a random sampling pattern. Environmental variables related to topography and remote sensing were extracted from the digital elevation model (DEM) and Landsat-8 satellite. The optimal environmental variables were selected using the recursive feature elimination method in the Silakhor Plain region. Soil property modeling was conducted using machine learning models such as random forest (RF), Support Vector Regression (SVR), Cubist (CB), and hybrid modeling. The modeling results showed that the RF model performed best for predicting CCE, pH, sand, and silt with R² values of 0.64, 0.65, 0.59, and 0.70, respectively. Additionally, the SVR model showed the highest accuracy for predicting SOC with an R² of 0.62, while the CB model had the highest accuracy for predicting clay with an R² of 0.66. The most suitable cell sizes for CCE, pH, sand, and silt were identified as 30*30 m, for SOC as 60*60m, and for clay as 90*90m. The most important environmental variables for SOC, pH, silt, sand, and clay were valley depth, differential vegetation index, and modified vegetation index, respectively. Overall, the results indicated that in the study areas, the use of intermediate scales (cell sizes of 30 to 90 m) led to higher accuracy in predicting soil properties. This is because using larger cell sizes introduces noise that hinders accuracy.
Maryam Osat; Shahrokh Fatehi; Javad Seyed Mohamadi
Abstract
Optimal utilization of production factors is considered one of the fundamental pillars of sustainable development. The increasing pressure on soil resources due to the population growth, industrial development, and the limitation of agricultural lands makes the optimal and sustainable use of soil essential. ...
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Optimal utilization of production factors is considered one of the fundamental pillars of sustainable development. The increasing pressure on soil resources due to the population growth, industrial development, and the limitation of agricultural lands makes the optimal and sustainable use of soil essential. Kurdistan Province, as one of the agricultural hub, is suitable for the development of orchard. The aim of this research is to determine the land suitability for the development of walnut, almond, apple, pear, grape, and cherry orchards in 3,000 hectares of the downstream lands of the Azad Dam to establish the optimal planting patterns. This study seeks to establish optimal planting patterns using the FAO standard method for land suitability assessment. Climatic characteristics, slope, flooding, drainage, texture/structure, coarse fragment, soil depth, CaCO3, pH, EC and organic carbon were examined in this study. Results show that in the relatively suitable class (S2), almond occupy the largest area with 561.4 hectares; in the critical suitability class (S3), walnut cover 679.4 hectares; and in the unsuitable class (N), pear account for 1,275.1 hectares representing the most significant area. This crops have no limitations in terms of salinity and alkalinity. The minimum and maximum climatic limitations correspond to almond and pear, respectively. The most important limiting factors for these crops include slope, soil depth, and texture. In steep land with deep soil, following soil conservation principles can enhance effective utilization and improve the land's suitability class. In steep lands of the region, if there is appropriate soil depth and the principles of soil conservation are implemented, it is possible to reduce the limitations of slope and improve land suitability classes.
Seyed Masoud Soleimanpour; Omid Rahmati; Samad Shadfar; Maryam Enayati
Abstract
Field measurements of soil loss due to gully erosion are very time-consuming and costly, so direct measurement of gully erosion at large scales is a time-consuming, costly, and labor-intensive process. For this purpose, the present study attempted to accomplish this by modeling soil loss due to gully ...
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Field measurements of soil loss due to gully erosion are very time-consuming and costly, so direct measurement of gully erosion at large scales is a time-consuming, costly, and labor-intensive process. For this purpose, the present study attempted to accomplish this by modeling soil loss due to gully erosion using random forest and support vector machine learning models and evaluating their efficiency in the Mahurmilati watershed located in the southwest of Fars province. Field measurements of dimensional parameters of 70 gullies were conducted over four years (2021 to 2024). In the modeling process, 15 environmental factors were considered as independent variables and the rate of soil loss in ditches as the dependent variable, and modeling was performed with a cross-validation approach. The accuracy of the models was evaluated using quantitative criteria such as root mean square error (RMSE), coefficient of determination (R2), root mean square error (RSR), and correlation coefficient (d). The rate of soil loss in gullies during the study period was 15300.94 tons. The results of the model prediction accuracy evaluation showed that the random forest model has better performance than the support vector machine model in terms of evaluation criteria and was introduced as the superior model for predicting the rate of soil loss due to gully erosion. The findings showed that "modeling" can provide valuable services to water and soil conservation management in saving time and money. For this purpose, it is suggested that the use of artificial intelligence-based models and machine learning structures be given more attention in future research.
Reza Erfanzadeh; Fatemeh-al-Sadat Hosseini; Seyed Homzeh Hosseini Kahnuj
Abstract
In this study, the effect of the canopy of Pteropyrum aucheri on the soil seed bank was investigated in southern Kerman province, Sehchah village rangelands. By studying the seed bank at two depths of 0-5 and 5-10 cm under and outside the canopy of this shrub species, the potential of the soil seed bank ...
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In this study, the effect of the canopy of Pteropyrum aucheri on the soil seed bank was investigated in southern Kerman province, Sehchah village rangelands. By studying the seed bank at two depths of 0-5 and 5-10 cm under and outside the canopy of this shrub species, the potential of the soil seed bank in preserving and recovering of the valuable medicinal species Pergularia tomentosa was evaluated. For this purpose, 15 individuals of the P. aucheri were selected in which P. tomentosa could also be observed under the canopy of P. aucheri. Soil sampling was carried out from under and outside the canopy from both depths, totally of 60 samples. Under the canopy (and also outside the canopy), 10 soil augers were taken. The soil samples were transferred to the greenhouse in Faculty of Natural Resources, Tarbiat Modares University, and the species present in the soil were identified using the seed germination method. In the greenhouse cultivation, a total of 2164 seeds germinated. Of these, 1486 seeds belonged to the under-canopy (1156 seeds at the upper depth and 330 seeds at the lower depth) and 678 seeds belonged to the outside of the canopy (341 seeds at the upper depth and 337 seeds at the lower depth). The density of the seed bank at the upper depth was significantly higher in the under-canopy than outside the canopy. This study showed that the valuable species of P. tomentosa not only had a seed bank under the canopy but also did not form a canopy outside the canopy of P. aucheri. Therefore, for the conservation and restoration of this species, it is not possible to rely on soil seed bank.
Leila Shariatyniya; Mehdi Ghorbani; Hossein Azarnivand; Majid Rahimi
Abstract
Rangelands, as socio-ecological systems, play a vital role in ensuring food security and livelihoods for communities. However, climate change and human factors pose serious threats to these ecosystems. In response to these challenges, governments have supported restoration and rehabilitation efforts ...
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Rangelands, as socio-ecological systems, play a vital role in ensuring food security and livelihoods for communities. However, climate change and human factors pose serious threats to these ecosystems. In response to these challenges, governments have supported restoration and rehabilitation efforts for rangelands. Natural resource governance has emerged as a novel approach in managing these systems, aiming to ensure the sustainability of rangelands by creating a shared understanding of resource conditions and suitable management regulations, as well as enhancing adaptive capacity in the face of the complexities of environmental changes and the uncertainties they bring.This study employs a social network analysis approach, utilizing the snowball sampling method and applying indicators of intra-group and inter-group link densities, as well as core-periphery structures. It assesses the status of cooperation and knowledge transfer relationships within the rangeland governance system in the Tarash County among stakeholders engaged in protective, developmental, and intermediary roles. The findings indicate a high degree of inter-group connections and the presence of strong structural openings, alongside a low level of intra-group connections and a network that remains less than optimal. This suggests that the knowledge structure governing rangelands in the area is not based on negotiation and is characterized by surplus knowledge processes, highlighting the inefficiency of ecological knowledge flow in enhancing adaptability among the organizational stakeholders involved in rangeland management in Tarash County.This study emphasizes the importance of social capital and reciprocal learning in strengthening collaborations and collective decision-making, demonstrating that establishing consensus among stakeholders with diverse objectives is key to successful adaptive governance.
Elham Rafiei Sardooi; Mina Eghtedarnejad; Shapour Kohestani
Abstract
Since that the traditional methods are based on meteorological station data and more investigate meteorological drought, hence, the application of remote sensing techniques and satellite images have been considered as a useful tool for monitoring of agricultural drought. In this study, the relationship ...
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Since that the traditional methods are based on meteorological station data and more investigate meteorological drought, hence, the application of remote sensing techniques and satellite images have been considered as a useful tool for monitoring of agricultural drought. In this study, the relationship between the meteorological drought index (SPI) and remote-sensing-based indices (VCI, TCI and VHI) has been studied in Bam plain. In this regard, using Terra satellite images (Modis sensor) and precipitation data of synoptic and rain gauge stations in the study area, the occurred changes were detected over the 15-year period. In this study, with respect to high temporal accuracy and spectral coverage and accessibility, MOD13A3 and MOD11A1 products extracted from MODIS sensor were used during 2009 to 2023. Then, indices of VCI, TCI and VHI were compared with Standard Precipitation Index (SPI). The results of drought mapping with the SPI index during 2010 to 2024 showed that the drought severity has increased from north to south in the study area. So that, extremely drought is detected in the southern regions of the plain and extremely wet is detected in the northern regions. The annual correlation coefficient between SPI, VCI and SPI indices is 0.70 and 0.53, respectively. It shows high significant positive correlation at level of 0.05. The correlation coefficient between SPI and TCI is 0.11 which shows a weak correlation but significant positive at level of 0.05. Therefore, VCI and VHI Indices have more correlation with annual precipitation and have acceptable results compared with TCI Index.
Ahmad Zare; Seyed Amir Mousavi
Abstract
An experiment with 10 constant temperatures (5, 10, 15, 20, 25, 30, 35, 40, and 45°C), was conducted in 2019 at the Agricultural Sciences and Natural Resources University of Khuzestan based on completely randomized design (CRD) with 8 replications to investigate germination and determine the cardinal ...
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An experiment with 10 constant temperatures (5, 10, 15, 20, 25, 30, 35, 40, and 45°C), was conducted in 2019 at the Agricultural Sciences and Natural Resources University of Khuzestan based on completely randomized design (CRD) with 8 replications to investigate germination and determine the cardinal temperature of Physorhynchus chamaerapistrum (Boiss.) Boiss. The highest seed germination was 86% at 25°C. Germination percentages at temperatures of 10, 15, 20, 30, 35, and 40°C were 77%, 83%, 85%, 85%, 34%, and 13%, respectively. No germination was observed at 5 and 45°C. The relationship between imbibition time and cumulative germination percentage was described by a three-parameter sigmoid equation. According to this equation, the results indicated that the shortest time required to reach 50% germination (T50) was observed at 25 and 30°C (33 and 34 hours), and the longest at 10 and 40°C (106 and 141 hours). T50 for temperatures of 15, 20, and 35°C was predicted to be 76, 37, and 51 hours, respectively. According to the dent-like model, the base temperature, lower optimal temperature, upper optimal temperature, and ceiling temperature were predicted to be 16.5, 22.91, 29.52, and 43.45°C, respectively. The results of this study showed that this plant could have the highest germination percentage from November to January, considering the growth conditions. Therefore, during these months, plans for managing this rangeland plant (seed dispersal and rangeland restoration) and issues related to grazing management should be considered.
Zahra Heidari Ghahfarrokhi; Pejman Tahmasebi; Ali Asghar Naghipour
Abstract
Assessing rangeland health is of great importance due to its impact on ecosystem sustainability. This study investigated the relationship between evaluation criteria of rangeland health and functional diversity indices in part of the Sabzkouh Protected Area (Chaharmahal Va Bakhtiari Province, Iran). ...
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Assessing rangeland health is of great importance due to its impact on ecosystem sustainability. This study investigated the relationship between evaluation criteria of rangeland health and functional diversity indices in part of the Sabzkouh Protected Area (Chaharmahal Va Bakhtiari Province, Iran). For this purpose, four rangeland sites with different grazing intensities (reference, light, moderate, and heavy grazing) were selected. In each site, two representative areas were sampled using three 30×30 meter macroplots. Plant functional traits, including plant height, various leaf traits, mean crown diameter, and growth form, were measured. Functional diversity indices, including Functional Richness, Functional Evenness, Functional Dispersion, Rao’s Quadratic entropy and growth forms, were calculated using the FD package in R 4.4.2. Additionally, three evaluation criteria of rangeland health, including soil/site stability, hydrologic functions, and biotic integrity, were evaluated. The data were analyzed using ANOVA, correlation, and univariate regression tests, employing the aov and duncan.test functions and the R packages ggcorrplot, dplyr, reshape2, ggpubr, and ggpmisc for 21 data pairs. Results revealed that soil/site stability, hydrologic function, and biotic integrity had significant positive relationships with certain functional traits such as leaf dry weight (R² = 0.6), leaf area (R² = 0.5), leaf length (R² = 0.5), perennial forb (R² = 0.3), and perennial grass (R² = 0.5). Conversely, negative correlations were observed with other indices including functional divergence (R² = 0.5), functional dispersion (P < 0.05), mean crown diameter (P < 0.05), annual grass (P < 0.05), and shrub (R² = 0.5). These findings emphasize the importance of incorporating quantitative biodiversity indices alongside qualitative assessments to improve rangeland management and develop a quantitative evaluation protocol.
Sahereh Safarlaki; Azadeh Safadoust; Mahmood Rostaminia; Seyedeh Bahareh Azimi
Abstract
Accurate spatial data on soil property distribution is crucial for monitoring of land resources, informed management practices, and robust environmental modeling, especially in arid and semi-arid regions. This study aimed to develop a spatial prediction model for soil salinity in the Meymeh Plain, Dehloran ...
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Accurate spatial data on soil property distribution is crucial for monitoring of land resources, informed management practices, and robust environmental modeling, especially in arid and semi-arid regions. This study aimed to develop a spatial prediction model for soil salinity in the Meymeh Plain, Dehloran Province. The Random Forest (RF) algorithm was employed to investigate spatial variations in soil salinity within the surface (0–30 cm) and subsurface (30–60 cm) soil layers. Soil samples were collected from 100 sites, analyzed for electrical conductivity (EC), and the spatial variability of soil salinity was modeled using random forest (RF) analysis. Seven environmental variables of Greenery, Diffuse Radiation, Valley Bottom Flatness Index, Normalized Difference Vegetation Index, Salinity Index, Wind Direction Index, and Brightness were selected based on the Variance Inflation Factor, including parameters from a digital elevation model and Sentinel-2 satellite reflectance data. The model used 80% of the data for calibration and 20% for validation, with performance assessed through root mean square error (RMSE), coefficient of determination (R²), and concordance correlation coefficient (CCC). The RF model showed high prediction accuracy for surface EC and relatively acceptable results for subsurface layers. The R² for the surface layer was 0.92, and for the subsurface layer was 0.37; the RMSE for the surface and subsurface layers was 0.22; and the CCC for the surface layer was 0.82 and for the subsurface layer was 0.97. Overall, topographic derivatives demonstrated a greater influence on predicting soil salinity in both surface and subsurface layers compared to remote sensing data. The multi-resolution valley bottom flatness index with high spatial resolution was identified as the most important predictor of soil salinity, highlighting the impact of topographic factors in the study area.
Davod Nazari Chaleshtori; Pejman Tahmasbi; Ali asghar Naghipour; Hojatollah Khedrigharibvand
Abstract
The achievement of sustainable rangeland management depends on addressing the socio-economic issues of rangeland users, particularly securing their livelihoods. This study aimed to determine the minimum economic level of rangeland by examining four regions with two rangeland conditions—good and ...
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The achievement of sustainable rangeland management depends on addressing the socio-economic issues of rangeland users, particularly securing their livelihoods. This study aimed to determine the minimum economic level of rangeland by examining four regions with two rangeland conditions—good and poor—located in steppe and semi-steppe vegetation zones. Annual forage production was estimated using a double sampling method. The socio-economic information of the statistical population was collected through interviews and the Statistical Center of Iran and Statistical Yearbooks. Rangeland related expenses and incomes of rangeland users were calculated. By examining the costs and incomes, the economic level of the rangeland was determined in such a way that it can provide the household expenses according to the level of livelihood. Based on the results minimum economic level of rangeland for each household, respectively, in poor rangeland situations; In steppe and semi-steppe rangelands with the area of 932 and 830 hectares, it had the highest amount and in semi-steppe rangelands with a good condition, the area of 81 hectares had the lowest amount in a 100-day grazing season. In general, the condition of the rangeland and climate affect the economic level of the rangeland for each household. These findings could help rangeland policy makers in recognizing and solving the socio-economic issues of rangeland users. It is suggested that while conducting comprehensive studies, the minimum economic level of the country's rangelands should be determined to be used in the management and planning of the country's rangelands.
Hossein Moradi; Mohammad Jafari; Hossein Azarnivand; Mohammad Tahmoures; Esmaeil Alizadeh
Abstract
Integrated rangeland ecosystem management is recognized as an effective strategy for improving vegetation cover, forage production, and enhancing sustainability in arid and semi-arid regions. In this study, the effects of various conservation and ecosystem restoration measures (including seeding, planting, ...
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Integrated rangeland ecosystem management is recognized as an effective strategy for improving vegetation cover, forage production, and enhancing sustainability in arid and semi-arid regions. In this study, the effects of various conservation and ecosystem restoration measures (including seeding, planting, terracing combined with planting, contour banding with planting, pitting with seeding, and contour furrowing with planting) were investigated on vegetation characteristics and forage production in the rangelands of Vardij village, Tehran Province. Sampling was conducted systematically and randomly during the growing season using 4 m² plots along 100-meter transects. Vegetation characteristics were precisely recorded and the related data were analyzed. The results indicated that the aforementioned conservation measures had significant effects on vegetation variables, leading to a remarkable increase in vegetation canopy cover and a reduction in bare soil. The highest mean canopy cover (59.97%) and the lowest percentage of bare soil (7.93%) were observed in the planting treatment, whereas the control rangelands had the lowest canopy cover (23.2%) and the highest bare soil percentage (29.2%). Other methods, such as seeding and terrace planting, also showed positive effects on vegetation cover improvement. Regarding forage production, the planting treatment yielded the highest mean production (423 kg/ha), followed by seeding (367 kg/ha) and terrace planting (388 kg/ha). The control rangelands exhibited the lowest forage yield. These findings highlight the crucial role of conservation and restoration measures in enhancing vegetation cover and rangeland sustainability. Accordingly, it is recommended that future management plans utilize a combination of methods, including planting and seeding, to improve the quality and sustainability of rangeland ecosystems.
Seyedsaeid Nabavi; Arash Malekian; Naser Mashhadi; Khaled Ahmadaali; Raoof Mostafazadeh; Ali Shabazi
Abstract
The Baliqlu Chay River watershed in Ardabil Province is a key water source for regional demands. In this study, the role of climate change and human activities on streamflow is examined by using hydrological indices and trend analysis over the period 1991-2021. Monthly, seasonal, and annual climatic ...
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The Baliqlu Chay River watershed in Ardabil Province is a key water source for regional demands. In this study, the role of climate change and human activities on streamflow is examined by using hydrological indices and trend analysis over the period 1991-2021. Monthly, seasonal, and annual climatic and discharge variables were assessed for trends using the Mann-Kendall trend test and Sen's slope estimator. Results indicate streamflow is controlled by seasonal snowmelt, groundwater reliance, and the controlling impact of the Yamchi Dam. Moreover, the high flow variability observed at the Yamchi Station, as indicated by elevated standard deviation and coefficient of variation values, suggests an increased risk of flooding in this area. Trend analysis results over the 30-year statistical period reveal a decreasing trend in annual precipitation at the Ardabil and Nir stations, although these trends are not statistically significant at the 99% and 95% confidence levels. In contrast, a statistically significant increasing trend in annual precipitation was detected at the synoptic station in Sareyn at the 99% confidence level. Additionally, the annual temperature increase at all stations was found to be statistically significant at the 99% confidence level. The assessment of streamflow trends on an annual scale at the Nirchay and Yamchi Dam hydrometric stations indicates a statistically significant decreasing trend at the 1% level (p-value ≤ 0.01). These results emphasize the urgent need for sustainable water management strategies, including optimization of resource use, revised consumption patterns, and improved operation of the Yamchi Dam. Such interventions are essential to reduce the negative impacts of climate change and anthropogenic pressures on the river’s hydrological regime.
Vahideh Moradzadeh; Ardavan Ghorbani; Leila Nemati Sham-Asbi; Mehdi Moameri; Zeinab Hazbavi; Ali Teymourzadeh; Behzad Behtari
Abstract
Rangelands, as natural ecosystems, play a significant role in maintaining carbon balance of the environment. This study aimed to Identification of Carbon Sequestration Patterns under the Influence of Climatic, Soil, and Topographic Factors in the Rangelands of Northern Sabalan, located in Meshginshahr ...
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Rangelands, as natural ecosystems, play a significant role in maintaining carbon balance of the environment. This study aimed to Identification of Carbon Sequestration Patterns under the Influence of Climatic, Soil, and Topographic Factors in the Rangelands of Northern Sabalan, located in Meshginshahr County. Soil sampling was conducted in two types of vegetation cover- grassland and shrubland- across four main geographical directions and at two soil depths (0–15 and 15–30 cm). Data were collected for 24 different soil properties. To perform statistical analyses, the normality of the data was first assessed, followed by a one-way analysis of variance (ANOVA) and Duncan’s multiple range test to compare the mean values of different properties between grasslands and shrublands. Principal Component Analysis (PCA) was also used to evaluate data structure. The results revealed that clay content, silt, organic carbon, particulate organic carbon, total nitrogen, and soil carbon sequestration were significantly higher in grasslands than in shrublands (p<0.01). In contrast, sand content, pH, and electrical conductivity were significantly higher in shrublands than in grasslands (p<0.01). The northern slope exhibited higher levels of clay, silt, organic carbon, and carbon sequestration compared to the southern slope. Additionally, increasing soil depth led to decreases in organic carbon, total nitrogen, and carbon sequestration. PCA showed that the first two components explained 36.30% of the total variance. Sand content, precipitation, and organic carbon having the highest correlation with the first component, while slope percentage and litter showing the strongest correlation with the second component. These findings indicate that soil physical and chemical properties- particularly those affected by climatic gradients and topography- significantly influence carbon sequestration.
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