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.
Behnaz Attaeian; Ali Badrestani; Saeid Khosrobeigi Bozchelui; Mohammad Mehdi Artimani
Abstract
Soil organic carbon as a key factor in soil stability and fertility is considered as one of the important environmental challenges in the context of climate change. The aim of this study was to determine soil organic carbon zonation in Gonbad paired-watershed, Hamedan province. In this research, the ...
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Soil organic carbon as a key factor in soil stability and fertility is considered as one of the important environmental challenges in the context of climate change. The aim of this study was to determine soil organic carbon zonation in Gonbad paired-watershed, Hamedan province. In this research, the information of meteorology, soil science and erosion and sedimentation study of Gombad watershed was used, including the information of 49 profiles in the 0-15 cm soil layer. After collecting data, tests of normality (Shapiro-Wilkα test <0.05), homogeneity of variance, and then the relationship between independent variables and organic carbon were performed using Pearson's linear correlation in SAS software. Also, determining the most effective independent variable using multivariate analysis, PCA factor analysis was used in XlStat 2.1 software. In order to determine the distribution and amount of soil organic carbon in the Gonbad representative watershed, modeling using SVM support vector machine learning algorithms and RF random forest was used in R software.The results showed that 78.18% of soil organic carbon changes depend on four components. Clay and nitrogen percentage were selected as the most effective variables on soil organic carbon content, so that the first component of clay content explained 34% and the second component nitrogen explained 18% of variations. According to the results of the implementation of the SVM and RF Models, the SVM model with a CE factor of 0.86 and RMSE of 0.05 in the test stage is a more accurate model in this study.
Jaber Sharifi; Amrali Shahmoradi
Abstract
Vegetation changes rangelands, that usually occurs in the composition and structure of vegetation over time. On the other hand, human factors, especially rangeland management, play an important role in maintaining stability or degradation. The purpose of this study was to investigate the dynamics of ...
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Vegetation changes rangelands, that usually occurs in the composition and structure of vegetation over time. On the other hand, human factors, especially rangeland management, play an important role in maintaining stability or degradation. The purpose of this study was to investigate the dynamics of vegetation under the local management was carried out from 2008 to 1391. To do this, main vegetative stepic regions of the factors related to crown cover, density and abundance were determined by multi-year and group species, during the three transects 500 m in 30 plots (5/1 × 5/1 meter) as well as soil moisture and organic carbon were measured. The results showed that a four-year period, In the vegetation of perennial grasses, such as Festuca ovina, Alopecurus aucheri, Bromus tomentellus and Koeleria caucasica their variation was due to rainfall in the growing season, there was no significant difference between study years. In shrub cover such as Onobrychis cornuta and Astragalus aureus were significantly different between years of study due to annual precipitation fluctuations and soil moisture moisture content. In perennial forbodies, such as Scorzonera radicosa, Polygonum alpetre and Veronica orientalis were affected by precipitation seasonal and there was a significant difference between years. Changes in soil organic carbon and the process is slow. Therefore the results of the survey year to year changes in vegetation,climate changes and soil moisture also how the soil erosion condition can as an appropriate guide for the correct current methods used for management of rangeland ecosystems.
