جستجوی مقالات مرتبط با کلیدواژه "ترسیب کربن" در نشریات گروه "کشاورزی"

This research was carried out to measure and estimate the amount of leaf biomass, carbon sequestration, and leaf area index of Montpellier maple (Acer monspessulanum L.) trees in three regions of Manesht and Qalarang protected areas of ​​in the forests of Sirvan County located in Ilam province. Using the random sampling method, 20 tree samples were selected from each region (60 trees in total) and their quantitative factors including the large and small diameter of the crown, tree height, crown length and collar diameter of the target trees were measured. Then, the leaves of one-fourth to one-eighth of the crown area of the sample trees were collected. After drying in the oven, the dry weight of the leaves was weighed. The weight of organic matter and carbon content of the leaves (0.47) were obtained, after burning sufficient dried leaves in an electric oven. The weight method was used to calculate the leaf area index. In addition, to generalize the results obtained from the sample trees to the whole forest, the mean tree method was used. The results showed that the average leaf biomass, average leaf carbon storage, and average amount of carbon dioxide absorption from the atmosphere were 221.28, 103.68, 380.50 (kg/ha) in Qalarang, 199.92, 100.38, 368.34 (kg/ha) in Manesht, and 186.32, 87.38, 320.68 (kg/ha) for MianTang, respectively. The average leaf area index of A. monspessulanum was estimated 1.52 for each tree and 0.119 per hectare in the study areas . Additionally, the economic value of the carbon sequestered in the leaves of A. monspessulanum was 21.045 dollars per hectare, which is estimated to be equivalent to 10522500 rials. In general, the difference in the investigated variables of A. monspessulanum species in the three study areas can be due to the difference in density per hectare of the species, the difference in the succession stages and the size of the trees in these areas, as well as the applied management strategies or the different degradation conditions in study areas.

Carbon storage in terrestrial ecosystems is an important part of global carbon storage and plays a vital role in mitigating climate change. The purpose of this research is to investigate the effects of different types of land uses/land covers (dense rangelands, semi-dense rangelands, low density rangelands, barren lands and agricultural lands) on the amount of soil carbon and plant biomass sequestration as an important ecosystem service in Sefiddasht watershed in in Chaharmahal va Bakhtiari province. Sampling of soil and vegetation was done randomly and systematically. For this purpose, 60 plots of 4 square meters were used for collecting soil, plant material and litter. Plant biomass was sampled by direct measurement method. Soil samples were also collected from the depth of 0-30 cm and 20 samples in each area. The results showed that there is a significant difference between the investigated regions in terms of total carbon storage. The total carbon storage from the highest to the lowest in order includes dense rangelands (46.42 tons/ha), semi-dense rangelands (38.49 tons/ha), agricultural lands (31.62 tons/ha), low-density rangelands (26.12 tons) per hectare) and barren lands (17.21 tons per hectare). The economic value of the total carbon storage per hectare of the examined uses, including dense rangelands, semi-dense rangelands, agricultural lands, low-dense rangelands, and barren lands, was determined to be $5446, $4516, $3710, $3065, and $2019, respectively. Therefore, it can be concluded that the implementation of appropriate policies to prevent or minimize the conversion of land uses with a higher carbon storage capacity to land uses with a lower carbon storage capacity is of particular importance.

The increase and storage of organic carbon in rangeland ecosystems, known as carbon sequestration, is a primary approach for reducing atmospheric carbon dioxide concentrations. The aim of this study is to evaluatecarbon storage within the plant-soil system under different management practices, including grazing exclusion, grazing, fertilization, and seeding. 24 samples of surface soil, along with 20 samples of leaf-litter and plant biomass (both aboveground and belowground), were collected using a systematic randomized design under different management conditions in the Khamsan sub-basin in the spring of 2014.The amount of organic carbon in soil and Plant tissue were measured using the Walkley-Black method and combustion in an electric furnace, respectively. The results showed that management methods have a significant effect on the amount of organic carbon in aboveground and belowground biomass, litter, and soil (p ≤ 0.0001). The average soil organic carbon storage was estimated at 111.2 tons per hectare under Exclosure Management, 85.5 tons per hectare under grazing management, 130.5 tons per hectare with Fertilizer management, and 139.4 tons per hectare with seeding management. The highest amount of organic carbon aboveground biomass, belowground biomass, and litter were observed under exclusion management (significant difference compared to seeding and grazing management), fertilization (significant difference compared to seeding, grazing exclusion, and grazing management), and fertilization (significant difference compared to grazing management), respectively, with mean values of 5, 1, and 4 kilograms per hectare. In general, the highest amount of organic carbon in the plant-soil system of the semi-steppe rangelands in Khamsan under various management was observed in soil, aboveground biomass, litter, and root, respectively.

According to extent of rangelands and their role in capturing and storing atmospheric carbon dioxide, the present research has been investigated. Carbon sequestration between two regions under livestock and wildlife grazing in the plain areas of Mehriz in Yazd province. For this purpose, in order to determine the level of steppe desert vegetation in two wildlife and livestock grazing sites, sampling of this dominant plant and soil in each of these areas was done in a systematic random way. Sampling of 30 dominant species was done in simple steppe and after cutting the aerial organs (leaves and stems) and roots, they were weighed. Along with plant sampling in each plot, soil samples were collected to the depth of 50cm   near the plants. In laboratory, the organic carbon percentage of plant and soil samples was determined Data analysis was done in SPSS software. The results showed that aerial biomass carbon sequestration in both wildlife (7.56 kg/ha) and livestock (6.90 kg/ha) sites had a significant increase compared to underground biomass and stem had the highest amount (p<0.01). The amounts of root carbon storage in wildlife and livestock sites were obtained as 3.61 kg/ha and 3.47 kg/ha, respectively. Also, the amounts of carbon sequestration of plant organs in the area under livestock grazing was lower than that of wildlife. In wildlife site, the amounts of carbon storage in aerial, underground and total plant biomass were 7.56 kg/ha, 3.61 kg/ha and 11.17 kg/ha, respectively, while in livestock site was 6.91 kg/ha, 3.47 kg/ha and10.37 kg/ha. About the soil, also a significant decrease in the amount of carbon sequestered in livestock site (6.76 tons/ha)) was observed compared to wildlife site (10.33 tons/ha). So, Therefore, unprincipled and excessive livestock grazing can be introduced as an important factor in reducing carbon sequestration in the region.

Plant and soil conservation play a vital role in effective rangeland management, especially in dealing with the threats caused by climate change. On the other hand, there exists a complex interaction between soil and vegetation in rangeland ecosystems, neither of which is solely dependent on the other. Moreover, various natural factors, including climate change, aridity, desertification, and drought, may accelerate the degradation of rangelands, making the identification of such a relationship a necessity for evaluating the potential for carbon sequestration in arid and semi-arid landscapes. In this regard, as rangeland ecosystems in Qahavand plain, Hamadan, have been influenced by drought and desertification, this study sought to examine the relationship between soil parameters and the key species of the Qahavand rangeland, that is, Camphorosma Monspeliaca L. , concentrating on the storage of organic carbon. 

to collect soil and plant samples from the study area during the mid-growing season, three transects and eleven plots were selected using a systematic randomized sampling method. The positions of the transects were chosen based on the overall slopes of the area, and the plots were selected randomly along each transect using Google Earth software and GPS. Moreover, soil samples were taken from depths of 0-15 and 15-50 cm, which were then transferred to the laboratory for analysis. In this regard, a total of twenty-two soil samples and eleven aerial biomass samples were collected for further chemical analysis so that changes in soil and plant properties can be studied. Finally, various parameters such as soil and plant organic carbon, soil texture, pH, EC, bulk density, total nitrogen, nitrate, and ammonium were measured, followed by the performance of statistical analysis and linear correlation using SAS v.9.4 software. 

Changes in the organic carbon content and their relationship with other parameters were investigated in the areas covered by Camphorosma Monspeliaca L. The results revealed no significant changes in organic carbon, acidity, total nitrogen content, nitrate, and ammonium at depths of 0-15 cm and 15-50 cm (P>0.05). Therefore, it can be argued that the presence of Camphorosma Monspeliaca L. species does not exert a significant influence on those parameters in surface and subsurface soils. On the other hand, notable changes were found in clay percentage and specific bulk density at both soil depths mentioned above. Moreover, Pearson's linear correlation analysis between soil parameters and organic carbon content indicated that except for silt percentage (p>0.05), there was no strong and significant relationship between the two. Generally, changes in soil organic carbon content, acidity, clay percentage, sand percentage, total nitrogen percentage, nitrate, and ammonium were found to have been aligned in the same direction. However, the organic carbon content showed an inverse relationship with other parameters. Therefore, it could be argued that except for silt percentage (r=-0.41, p ≤ 0.05), there was no significant correlation between soil organic carbon and the other parameters.While variations in soil organic carbon were generally expected to be found within the 0-50 cm depth, no significant changes were reported within the study area in this regard. In other words, the analysis of changes in soil organic carbon and linear correlations did not show any substantial difference in the organic carbon content between the surface and subsurface layers of the soil covered by Camphorosma Monspeliaca L, indicating that no significant alteration has occurred in soil organic carbon storage within the 0-50 cm depth of Qahavand rangelands which is dominantly covered by Camphorosma Mmonspeliaca L. The phenomenon could be attributed to the plant's morphology and root growth patterns, considering the fact that Camphorosma Monspeliaca L. is characterized by a deep robust root system that can extend up to a depth of six meters and cover an area of 60-70 cm, contingent upon the groundwater depth. Furthermore, the absence of noticeable changes in other key properties of both surface and subsurface soil may also be related to such a phenomenon.Additionally, no significant correlation was found between the organic carbon storage in surface and subsurface layers of the soil and the plant’s organic carbon. It should be noted that interactions among numerous factors play a crucial role in predicting soil carbon reservoirs and that inorganic carbon could potentially constitute a significant reservoir in Qahavand rangeland soils. Accordingly, it is recommended that a broader range of physical and chemical properties of both the soil and Camphorosma Monspeliaca L. be monitored to gain a comprehensive understanding of soil carbon sequestration within the region. Based on the average soil organic carbon content and soil bulk density, estimations suggest that the potential for soil organic carbon sequestration within the 0-50 cm depth of Qahavand rangelands approaches 90.9 tons per hectare.

The use of fossil fuels and land use change has caused a catastrophic increase in carbon in the atmosphere, which has led to a decrease in soil quality, global warming, and climate change. The deficiency of organic matter, salinity and alkalinity of the soil are three important limitations of the soils of winter rangelands in Iran. Biochar is a carbon-rich material that is produced during the pyrolysis process from raw materials containing carbon at high temperature and under almost oxygen-free conditions. It is used to improve soil quality, carbon sequestration and remove pollutants from the environment. Biochar can be engineered/designed for specific applications or to achieve specific results. Increasing the percentage of stable carbon and improving the physico-chemical properties of engineered biochars can play an important role in carbon sequestration and improving the properties of winter rangelands soils. After washing and drying, the cotton stalk was cut into pieces of less than 2 cm. Then it was immersed for 4 hours in a solution with a concentration of 20% metal salts of calcium chloride, magnesium chloride and iron chloride, and dried again. Then, in the electric furnace, at various temperatures of 300, 400, 500, 600 and 700 degrees centigrade, within two hours, 20 biochars (control and engineered ) were produced from treated cotton stalks with different metal salts and untreated cotton stalks. Finally, properties of produced biochars including yield percent, organic carbon percentage, stable carbon percentage, acidity and salinity were measured. Statistical analysis was performed in SPSS16 software using one-way analysis of variance and Tukey's test. The yield of produced biochars (control and engineered) significantly decreased with increasing temperature, so that the highest percentage of their yield was observed at pyrolysis temperatures of 300 °C. The highest percentage of yield (50.20%) was obtained in biochar treated with iron chloride produced at 300°C. The highest organic carbon (50.97%) and stable carbon (99.57%) were obtained in control biochar produced at 500°C and biochar treated with iron chloride produced at 700°C, respectively. The highest increase in the ratio of the weight of stable carbon to the weight of the feed stock was observed in biochar treated with iron chloride produced at 300 °C. The lowest and highest electrical conductivity (1.1 and 7.43 dSm) were obtained in control biochar produced at 300°C and calcium chloride treated biochar produced at 700°C. The highest and lowest acidity (9.83 and 5.60) were observed in control biochar produced at 700°C and iron chloride treated biochar produced at 300°C. Considering the limitations in the soil of Iran's winter rangelands and the characteristics of control and engineered biochars along with the energy required for their production, Biochar produced from cotton stalks treated with iron chloride salt at 300°C has the highest performance and high stable carbon, the lowest acidity and acceptable electrical conductivity, therefore, it is recommended to use in carbon sequestration and plantation projects in winter rangelands of Iran.

Rangeland ecosystems cover more than half of the earth's land surface, these ecosystems have high carbon sequestration and cause the formation of about 10% of the total biomass carbon reserves and 30% of soil carbon. Carbon sequestration potential differs according to plant species, habitats, and management methods. Each ecosystem has a certain potential which is determined by utilizing of natural vegetation, climatic conditions, and physical and chemical properties of the soil. Moreover, the amount of carbon in the soil and plants depends on the characteristics of topography, and any change in the elevation and slope of the habitat will affect the amount of organic carbon in the soil and plant cover and carbon sequestration. Therefore, it is important to determine the effects of elevation and slope characteristics, type of vegetation and canopy cover, and soil characteristics on the amount and changes of carbon sequestration. In this study, the carbon sequestration capacity and its relationship with some physical and chemical characteristics of soil, topography, and rangeland habitat have been investigated.

Sampling was conducted in six sites in elevation gradient (from 1400 to 3600 m above sea level; rainfall from 350 to 700 mm; the mean temperature varies from -0.24 to 10.1 °C) in the north of Sablan Mountain, Meshginshahr County, Iran, including three sites with the dominant physiognomy of grass-shrublands and three sites with grassland in three elevation levels of less than 2000, 2000-2500 and more than 2500 m above sea level. In each site, soil sampling was conducted at two depths of 0-15 and 15-30 cm. The random-systematic method was used to study vegetation variables. In this way, 10 plots of one m2 (based on the distribution pattern of plants) were established in each of the three transects with a length of 100 m along each transect. After determining the normality of the data and the homogeneity of the variance of the data,  two-way analysis of variance general linear model (GLM) was used for the overall comparison.

The results showed that with the increase in elevation in the two investigated habitats (grassland and grass-shrubland), the carbon sequestration in the soil increased. Moreover, the results indicate that the depth of the soil has a significant effect on the carbon sequestration capacity. Thus the highest amount of soil carbon deposition is in the soil depth of 0-15 cm in the grassland habitat with an elevation of more than 2500 m (70.53 gr cm-2), then the depth of 0-15 cm in the grass-shrub habitat. At an elevation of more than 2500 m (63.98) and a soil depth of 30-15 cm, the grassland habitat is at an elevation of 2000-2500 m (62.73), and its lowest amount belongs to a soil depth of 30-15 cm. The grass-shrub habitat is at an elevation of less than 2000 m. The results of the correlation analysis of carbon sequestration in habitats and different elevation classes indicate a negative relationship with the percentage of sand, acidity, and electrical conductivity of the soil, and a positive correlation with the percentage of clay and silt, the percentage of organic carbon and organic matter, the percentage of carbon, particulate organic matter, soil nitrogen, and total vegetation cover has shown.

The distribution of carbon stocks between biomass and soil varies among ecosystems and is influenced by elevation, so that the carbon sequestration potential is more significant in high elevation classes than in lower classes. Based on the estimated carbon values in the studied habitats, it can be concluded that the higher percentage of canopy cover and density preserves more moisture and prevents evaporation, which in turn can affect the amount of cover and density. Therefore, the effect of vegetation in different elevation classes on the amount of changes in soil carbon deposition is confirmed based on the results obtained in this research. Overall, the carbon sequestration potential is different according to habitat and elevation classes; therefore, by better understanding these factors and investigating the management factors that affect the sequestration process, we can take steps towards strengthening carbon sequestration and sustainable management of rangelands.

Tree species can cause changes in soil characteristics and organic carbon storage due to their tolerance to harsh environmental conditions. Therefore, by knowing the species that have more ability to store carbon, it would be possible to follow the improvement and regeneration of urban forests from the perspective of carbon sequestration index. Haloxylon ammodendron and Tamarix hispida shrubs are among the important halophyte species of the Irano-Turanian vegetation zone. In these areas, it is important the role of these shrubs in storing carbon and increasing plant biodiversity. The current research aims to investigate the soil carbon sequestration and plant biodiversity indicators in the habitats of these two species in Qom province.

The natural habitat of Tamarix located in Mesila plain of Qom province and the cultivated habitat of Haloxylon in 1362, located in Hossein-Abad area of Mish-mast in Qom plain with arid climate. Soil sampling was done randomly on one hectare with 30 samples from the eastern direction under the canopy and outside the canopy, by a cylinder at the depth of 0-15 cm in both Haloxylon and Tamarix habitats separately. Sampling was done to calculate the soil organic carbon reserve to obtain the apparent specific mass and organic carbon and some soil physical and chemical factors. To study the vegetation coverage in each habitat, from a plot of 400 m2 with the method of implementing the plot in the form of four plots of 10 x 10 meters in order to better distribute it on the surface of one hectare, and to study the vegetation of the floor from 20 micro-plots of one m2 (five micro-plots in each plot) was used. The values of species diversity in each microplate from each sample plot was calculated using Simpson, Shannon-Wiener indices and species richness using Margalef, Menchick and uniform indices with Pillo and Sheldon indices. Spearman's test was used to calculate the correlation between soil carbon deposition factors and some physical and chemical factors.

The average of all measured factors in the soil was higher for Tamarix. The effect of species and sampling position and the mutual effect of species in sampling position on the amount of acidity factors, percentage of organic carbon, potassium and carbon deposition (organic carbon storage) of the soil had a significant difference at the level of 5%. Furthermore, based on the comparison of the average of the treatments, it was found that the highest amount of soil carbon deposition is in the treatment under canopy of the Tamarix shrub with the amount of 191.13 tons per hectare. The results showed a significant difference in the amount of soil carbon sequestration between two species of Haloxylon and Tamarix, and it is higher in Tamarix soil. Soil characteristics such as carbon deposition, %OC, pH and K under canopy of Tamarix are higher than outside the canopy. The correlation between carbon sequestration characteristics and other factors showed that OC, pH and EC factors can be used as the most important influencing factors to estimate soil carbon sequestration. The indicators of plant biodiversity, including species diversity, species richness and uniformity, were calculated for each micro-plot only in Haloxylon habitat, because the Tamarix habitat was lack of floor cover and reproduction due to severe drought stress. The Menhinik and Margalef indices with the values of 1.39 and 1.68, respectively, have assigned the average species richness of Haloxylon habitat.

Due to the positive effect of Tamarix on the increase of organic matter and soil carbon deposition, which improves the soil structure in the long term, as well as the ability to adapt and resist the dry and fragile weather conditions of Mesileh region. The revival of this valuable species is vital and it is a suitable species for forestry in areas with such characteristics. Likewise, considering the positive effect of Haloxylon species in increasing habitat biodiversity indicators, which in the long term protect the soil structure, the issue of preserving and revitalizing these valuable plants is necessary for Qom province.

Biochar is a carbon-rich charcoal material resistant to decomposition, which is produced by heating biomasses in an oxygen-free environment or with limited oxygen. It is used with the aim of increasing organic carbon and improving the physical, chemical and biological characteristics of the soil. Thus its use in the low-fertile soils of hot and dry regions of Iran, which are often deficient in organic carbon, is important. Addition to its high stability in the soil, biochar can sequester atmospheric carbon dioxide in the soil for several hundred to several thousand years. In addition, it can improve soil fertility for a long time by affecting its physical, chemical, and biological properties. The stability of biochar is affected by several factors, such as the characteristics of biochar and soil, the interaction of biochar with soil components and environmental factors, which are examined in this article. Therefore, it is important to use biochar in the soils of arid and semi-arid regions of Iran, which are often deficient in organic carbon.

In this review article, while investigating the evidences of the high stability of biochar in the soils, the   most effective factors the fate of biochar in the soil, including the mechanisms of biochar removal from the soil, biochar stabilization in the soil, and interactions of biochar with soil components, and the gaps and required research areas are presented.

Biochar is higher resistant to degradation than the original carbon compounds in biomass. However, by interacting with soil components, biochar undergoes changes over time and is removed from the soil. The intensity of these changes and biochar residence time in the soil depends a lot on the type of biochar; So, biochars produced from grassy biomass and biochars produced at low temperatures are less stable. In addition, biochar interacts with all soil components, including organic matter, mineral particles, nutrients, living organisms, and soil water and atmosphere, and the result of these interactions determines the stability of biochar in soil. External factors such as the presence of plant and induced root changes, wind and water erosions, leaching, and fire also affect the fate of biochar in the soil. Among these, considering the interactions between microorganisms and biochar in soil, it seems that soil microorganisms play the most important role in the decomposition and destruction of biochar in soil. However, mechanisms such as the entrapment of biochar particles inside aggregates, binding of biochar with organic and inorganic components of soil, and inactivation of soil enzymes by biochar can increase the stability and durability of biochar in soil.

Considering the very high stability of biochar in soil and the necessity of increasing soil organic carbon as the main factor of soil fertility factor, the use of biochar in Iranian soils it can directly and indirectly improve the fertility of these soils while increasing soil organic carbon. However, after biochar is added to the soil, it interacts with the soil components and its characteristics change and evolve over time (aging). However, due to the novelty of biochar technology and the wide range of its application fields, our information on its interactions with various soil components, its long-term changes and developments in the soil and environment, and its long-term effects on the soil and the environment are not yet clearly defined and much research is needed in this field.

More than 80% of Iran's area is arid and semi-arid. Arid and semi-arid soils have various problems and limitations. One of the most important factors limiting soil fertility and crop production in these areas is the lack of soil organic matter (SOM). In more than 60% of Iran's agricultural lands, the amount of SOM is less than 1%; While its optimal level in soils should be 2-3%. SOM, as one of the most important indicators of soil health, plays a vital role in soil fertility and crop production; So, by increasing the amount of SOM, the physical, chemical, and biological characteristics of the soil and crop yield can be improved. However, the stability and residual effects of the fertilizers and organic wastes in the soil are low. Nowadays, converting organic wastes and residues into biochar and adding them to the soil is one of the new methods of increasing soil organic carbon, which enhance soil fertility and crop yield and has high residual effects due to its high stability. However, due to the specific characteristics of the soils of arid and semi-arid regions, using biochar in these regions is associated with challenges and has received less attention. In this review article, while reviewing the positive effects of biochar on soil quality indicators and crop production, the challenges of using biochar in the soils of arid and semi-arid areas, especially in drylands, and the solutions to overcome these challenges have been reviewed.

The objective of this research was to estimate the biomass, carbon storage and leaf area index of hawthorn species (Crataegus aronia L.) in Sartaf forests of Ilam city. For this purpose, using random sampling method, 30 hawthorn trees were selected and variables of collar diameter, tree height, crown length and large and small diameter of the crown were measured. Then, the leaves from 1/4 or 1/8 of the crown of sample trees were collected. After drying the leaves in the oven, the dry weight of the leaves was determined. After burning a sufficient amount of dried leaves in an electric oven, the weight of organic matter and carbon content of the leaves were obtained. The weight method was used to calculate the leaf area index. The results showed that the average leaf biomass, leaf carbon sequestration, and carbon dioxide absorption from the atmosphere were 99.18, 46.61, and 170.59 kg per hectare, respectively. The average leaf area index of hawthorn species was calculated as 9.08 for each tree and 0.095 per hectare in study area. The results of allometric relationships using different regression models showed a positive and significant correlation between the variable of mean crown diameter with the variables of biomass and leaf area index of hawthorn trees in Ilam forests. In general, the results of this research show the ability of using allometric equations to measure biomass, carbon sequestration, and leaf area index of Crataegus aronia.

Organic carbon is a crucial parameter for assessing soil fertility, productivity, and quality, particularly in dry and semi-dry lands. Rangelands cover approximately 50% of the Earth's land area and store over 33% of the global carbon reservoirs. Considering rangelands as significant terrestrial ecosystems and natural carbon reserves, understanding and quantifying carbon sequestration in these ecosystems is of great importance.

This research focused on rangelands in the southern domain of Damavand mountain. Four height groups were selected based on geographic conditions, regional plant cover, and slope. Each height group represented a different elevation range: group 1 (2504-2664 m), group 2 (2730-2896 m), group 3 (2923-3050 m), and group 4 (3119-3545 m). Soil sampling was conducted at two depths (0-15 cm and 15-30 cm) using 13 random points within each height group. Soil organic carbon and bulk density were measured, and carbon sequestration was calculated at the hectare level by multiplying organic carbon and depth. Regression equations and response surface models (RSM) were developed using design software to predict carbon sequestration and compare their accuracy.

Analysis of variance (ANOVA) showed that only sampling depth significantly affected soil carbon sequestration, while sampling height and the interaction between depth and height had no significant effect. Carbon sequestration was higher at a depth of 15-30 cm compared to 0-15 cm. Among the height groups, group 4 (3119-3545 m) exhibited the highest soil carbon sequestration, followed by group 1 (2504-2664 m). The highest carbon sequestration (6046.54 g/m2) was observed in height group 4 at a depth of 15-30 cm, while the lowest (2250 g/m2) was found in height group 2 at a depth of 0-15 cm. The quadratic model of the response surface methodology demonstrated higher accuracy (R2 = 0.7363) in predicting soil carbon sequestration compared to the linear model (R2 = 0.6014) and the less accurate regression model (R2 = 0.428). The response surface method successfully optimized the inputs, suggesting a height of 3500 meters and a specific depth to achieve a soil carbon sequestration amount of 8088.117 g/m2 with a satisfaction level of 0.976.

The response surface methodology (RSM) proved to be a valuable tool for predicting and optimizing soil carbon sequestration in rangelands, considering different sampling depths and heights. It can also be utilized for predicting various parameters in rangeland science, such as above and underground biomass volume and plant species coverage. RSM offers a novel approach for understanding and managing rangeland ecosystems.

The impact of grazing on the carbon cycle in mountain rangelands depends on various factors, including management practices and environmental conditions. However, the effects of grazing on carbon stocks remain uncertain due to challenges in tracking small changes in rangeland carbon stocks, lack of baseline information, and limited long-term grazing management data. This study aims to investigate the relationships between plant and soil parameters and organic carbon storage in a 10-year-old exclosure in the mountain rangelands of Asadabad, Hamadan.

Two study sites, one under grazing and the other under a 10-year-old exclosure, were selected in a manner that minimized the gradient effect of ecological and biological factors. Vegetation and topsoil samples were collected along two 100-meter transects at 20-meter intervals, resulting in a total of 10 plots in each area. Vegetation parameters, including percentage cover, diversity (Simpson index), evenness (Shannon-Wiener index), and richness (Margaluf index), were calculated using Past 4.03 software. Soil organic carbon, phosphorus, potassium, and nitrogen were measured. Statistical analysis was performed using SAS V.4.1 software, and the distribution of variables was analyzed using principal component analysis (PCA) in Canoco 5 software.

The findings revealed higher vegetation cover and plant diversity (richness and evenness) in the exclosure area. The vegetation cover percentage and species count in the grazing area were 35.1% and 127, respectively, while in the exclosure area, they were 67.6% and 139. The carbon stocks in vegetation and soil were significantly higher in the exclosure area, with values of 83.13 and 74.35 ton/ha in the soil surface, and 0.00219 and 0.00273 ton/ha, respectively (p < 0.05). The exclosure area exhibited a significant increase in Simpson diversity index (13.83) compared to the grazed area (12.63). Additionally, the Margaluf richness index showed a significant increase in the exclosure area. Soil phosphorus, potassium, and nitrogen nutrient measurements indicated an increase of 51%, 25.7%, and 15% in the exclosure area (p < 0.05). Correlation analysis revealed a significant linear relationship between organic carbon and phosphorus (r = 0.55) and nitrogen (r = 0.80) (p < 0.05). However, no significant correlation was observed between plant diversity indices and vegetation organic carbon storage.

The study demonstrated the positive impact of long-term exclosure on soil and vegetation parameters in mountain rangelands (p < 0.05). Exclosure not only enhanced plant and soil organic carbon storage but also resulted in increased soil nutrient levels, vegetation cover, and diversity and richness indices. The significant increase in plant diversity highlights the suitability of the Simpson index for evaluating diversity in mountain rangelands. However, the lack of a significant linear relationship between diversity index and organic carbon stocks in plants and soils suggests that factors other than plant diversity directly influence carbon stocks in mountain ecosystems.

Forest ecosystems are one of the principal sources of carbon storage. The Lirehsar forest in Tonekabon was studied to assess the carbon sequestration capacity of underground biomass, soil, and roots of beech and hornbeam mixed stands. Thirty samples of uprooted beech and hornbeam trees were unintentionally selected. Soil sampling was carried out at three depths (0-10, 10-30, 30-50 cm), and root diameter sampling was conducted in six classes (50 mm) from distinct parts of the root. Soil samples were passed through a 2 mm sieve, and root samples were dried and pulverized with a grinder. The carbon storage value in beech and hornbeam roots was 8404 kg.ha-1 and 6235 kg.ha-1, respectively. The total amount of carbon deposited in soil mineral layers from 0-10 cm to 30-50 cm depth on beech and hornbeam was calculated 121 and 161 t.ha, respectively. Furthermore, the study results on soil carbon sequestration in beech and hornbeam revealed that the amount of soil carbon sequestration in all layers was 56.9, 72.5, and 62.3 t.ha for hornbeam, while its value for beech in all layers was 42, 43.6, and 35.7 t.ha. The independent t-test results showed no significant difference between carbon stored in diverse root diameters in beech and hornbeam. Findings showed that the amount of soil carbon sequestration on hornbeam was higher than on beech in all layers, revealing the influence of species diversity on soil carbon sequestration. It is expected that a variety of different tree species can be employed for reforestation in suitable areas as a result of the species diversity effect on carbon storage and carbon sequestration compared to pure beech species. It is supposed that hornbeam is a mitigated species for decomposition of soil elements and carbon sequestration in forest soil due to the developed distribution of the studied species in Hyrcanian forests.

Over time, the development of human settlements and activities has led to an increasing demand for natural resources, including ecosystem services, which subsequently drives changes in land use. As the process of land allocation establishes a link between the natural environment and human resources, the competition among conflicting land uses becomes significantly important in this context. Various tools are employed to address conflicts among land uses and simulate changes in land use. The CLUMONDO model is one such tool that employs various ecosystem services in the allocation and transformation of land uses, allowing for the simulation of land use changes and land cover. In this research, the CLUMONDO model was utilized to predict the extent of changes in demand for major land uses within the Qareh-Sou watershed over a 10-year period (2020-2030). Variables such as slope, aspect, elevation, the number of neighboring urban cells in a 7x7 grid., temperature, precipitation, distance from rivers, distance from urban areas, and distance from roads were incorporated into the model. An optimization approach was implemented to simultaneously enhance carbon sequestration capacity and designate additional residential areas in a specific scenario. The analysis of results was conducted using Idrisi Terrset and ArcGIS software. The findings indicated that over the next 10 years (2020-2030), land use changes for constructed areas and dense forests followed an increasing trend, while semi-dense forests and agricultural lands experienced a decrease due to their conversion into other land uses. This transformation was aimed at enhancing ecosystem services. This study showcases the possibility of harmonizing diverse, and at times conflicting, services in a way that also addresses human needs

Current study reviews effect of the Darabkola forest plant communities on Carbon sequestration in soil and Above Ground Biomass (AGB). It compared five natural communities, including Parrotio persicae-Carpinetum betuli, Zelkovo carpinifoliae-Quercetum castaneifoliae, Solano kieseritzkii-Fagetum orientalis, Aceri velutini-Parrotietum persicae, Euphorbio amygdaloidea-Fagetum orientale, and one Maple plantation stand. Sampling was done using systematic randomized with 400×400 meters dimensions. After removal of marginal points, soil samples were collected from center of 163 plots with 20×20 meters dimension. Results of ANOVA, mean comparison, and PCA showed that the highest soil Potassium belongs to the plantation stand (336.96±18.97), while the least one, belongs to Solano kieseritzkii-Fagetum orientalis (160.25±10.75). On the other hand, soil Phosphorus was the highest in the Aceri velutini-Parrotietum persicae (4.65±0.55), and it was the lowest in Solano kieseritzkii-Fagetum orientalis (1.95±0.14). Aceri velutinid-Parrotietum persicae (34.80±2.08) and Solano kieseritzkii-Fagetum orientalis (22.73±1.22) had the highest and the lowest soil moisture content, respectively. However, the study proved that different communities did not affect soil sand percent and carbon sequestration. Zelkovo carpinifoliae-Quercetum castaneifoliae (242.82±23.22) had the highest, and plantation stand (54.78±5.55) had the lowest carbon sequestration in AGB.

Ecosystem services are usually divided into four categories: (a) provision services, (b) regulating services, (C) cultural services and (d) supporting services. Ecosystem services are managed in agroecosystems primarily for food production. But, agricultural ecosystems provide provision, regulating and cultural services for human society. These services respond strongly to human socio-economic needs. Quantifying the various services and functions of agroecosystems is one of the most important effective strategies in order to increase attention pay to these services. Therefore, the purpose of this study was evaluation and quantification of ecosystem services in wheat (Triticum aestivum L.) agroecosystems of Dasht-e-Naz, Sari.

This experiment was performed as an unbalanced completely design in wheat agroecosystems of Dasht-e-Naz, Sari (Mazandaran province), during 2019-2020. In this study, 9 wheat plots with 4 cultivars including Tirgan, Ehsan, Collector and N-92-9 were surveyed and monitored. In this study, some ecosystem services such as insect and weed biodiversity (using Shannon-Weiner, Simpson, Margalf, Uniformity and Menhinick indices), soil microbial respiration, carbon sequestration, organic matter, abundance of earthworms, grain yield, protein content oxygen production, and soil protection (by the stability of aggregates) were evaluated and quantified. Soil samples were taken from a depth of 0-30 cm before wheat planting in November 2019 and after harvest in June 2020 for assessment of rate of microbial respiration, organic matter and carbon sequestration. Also, oxygen production was estimated based on net primary production. Sampling of yield and plant biodiversity was harvested based on W pattern and with quadrate 0.5 × 0.5 m2. All samples were moved to the crop research laboratory of Gorgan University of Agricultural Sciences and Natural Resources and the plant flora was determined by genus and species names.

The results showed that crop management and performance of intensive agricultural system were effective on providing many services of ecosystems in wheat fields of Dasht-e-Naz, Sari. These services are influenced by several factors such as cultivar type, crop rotation, tillage, etc. The results showed that the effect of different cultivars was significant on grain yield and protein percentage. The highest percentage of grain protein as a provision service was obtained from Ehsan cultivar (12.15%) and the lowest content was obtained about 11.42% from N-92-9 cultivar. The highest wheat grain yield and oxygen production were calculated from plots under Collector cultivar. In additional, the highest amount of carbon sequestration (2.33 ton/ha) and microbial respiration rate in before planting and after harvest (76.46 and 38.52 mg CO2 per kg of soil per day, respectively) belonged to plot 15. Also, it was determined that plot 15 was better than other plots from soil protection service view based on the diameter mean weight index (MWD) and the geometric mean diameter index (GMD). In this research, three beneficial insects (biodiversity assessment) were observed such as Coccinella septempunctata Linnaeus and Aphidius matricariae, and Chrysoperla carnea. The highest values of Shannon-Weiner and uniformity indices of weeds were as 2.63 and 0.82 in plots 23 and 15, respectively. Furthermore, Shannon-Weiner and uniformity indices of insect communities were obtained as 2.07 and 0.94 from plot 22, respectively.

 Generally, carbon sequestration, organic matter, microbial respiration, earthworm abundance, aggregate stability index, average weight diameter (MWD) and geometric mean diameter index (GMD) were better in plots 14 and 15 under wheat cultivation  than other plots. The results of this study showed that crop management and implementation of intensive agricultural system were effective in providing many ecosystem services in wheat fields in Dasht-e Naz region of Sari. So that, these services were affected by several factors such as cultivar, crop rotation and tillage methods.
Acknowledgment
The authors gratefully acknowledge the financial support of Gorgan University of Agricultural Sciences and Natural Resources and Dr. Hamid Sakinin for his help.

despite occupying a relatively small space, the border forests have the potential to accumulate more and faster carbon, are centers of biodiversity and provide many valuable ecosystem services. Riverine forests also affect plant biodiversity patterns, soil characteristics, and habitat quality. Despite having high environmental and conservation values, the riverine forests have been paid less attention as forest covers, and most of the studies related to the distribution pattern of species and characteristics of the animal community It was their soil. The aim of this research was to investigated the effect of different types of land use on the physical, chemical and carbon deposition characteristics of the soil along the Karkhe River. In this research, the effect of natural forest uses, forestry, agriculture and barren lands on the banks of the Karkheh River on some physical and chemical characteristics and soil carbon deposition was done. Thus, by random method, 30 points were selected in each field and soil samples were taken from a depth of 0-20 cm in the center of each plot. The characteristics of moisture percentage, texture, specific gravity, pH, electrical conductivity, organic carbon, total nitrogen, absorbable potassium and phosphorus, and calcium carbonate were calculated in the measuring laboratory and the amount of carbon deposition. Data were analyzed using one-way analysis of variance (ANOVA) and SNK mean comparison test. All statistical analyzes were performed using SAS 9 software. The results showed that agricultural use with 18.45% clay, natural forest and agricultural use with 46.29 and 43.92% silt, respectively, and forestry and barren land use with 60.47 and 56.86% sand, respectively. They showed a significant difference. Apparent specific mass increased during forest use change. The highest value of electrical conductivity with 3.17 decisiemens/meter was observed in barren lands, which had an increase of 71.35% compared to the natural forest. In agricultural use, absorbable potassium reached the lowest level with a decrease of 62.04% compared to the natural forest. According to the results, the change of use has a significant and decreasing effect on the amount of carbon sequestration, so that the natural forest has the highest amount of carbon sequestration with 63.37 tons per hectare, and the lowest carbon storage related to agricultural use with 41.53 tons. It was per hectare. In general, the forests along the river have more quality and soil carbon deposition, and the change of land use causes damage to these habitats. Investigating carbon sequestration in coastal ecosystems may help determine baseline conditions and can be used to strengthen restoration plans or address the impact of climate change on carbon stocks in these areas.

Access to real information and data on the impact of watershed management projects and their technical and economic evaluation is possible through representative and paired catchments. Since management operations and topographic characteristics have a great impact on carbon retention in ecosystems, this study aimed to determine the amount of soil organic carbon due to changes in some topographic factors including altitude, direction, and different percentages of slope and measurement and zoning of soil organic carbon before biological and mechanical watershed management operation.

For this purpose, 27 land units in a part of the rangelands of sample sub-basin with an area of 25 hectares were selected as the study area. soil samples were collected from plots with dimensions of 10 * 10 m2 per unit. Composite samples consisting of 5 soil samples were collected from the center and four corners of the mentioned plots from a depth of 0-10, Soil samples were analyzed for some soil properties; including, organic carbon, organic matter, texture, bulk density, electrical conductivity, and pH.. SAS v9.1 software was used for statistical analysis. After performing normality tests, homogeneity of variance was obtained by ANOVA analysis test. Then, Pearson correlation coefficient and linear regression analysis were used to evaluate the correlation and determine the relationship between independent and dependent variables (organic carbon) then, the evaluation of spatial changes of soil organic carbon and zoning map were investigated using the geostatistical method after testing the normality of the data, interpolation methods were used and the effective parameters were optimized. Finally, using the statistical criteria of Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) the amount of deviation of the actual data was measured with the estimated data and the best method for interpolation of soil organic carbon was determined.

The results showed no significant changes of soil organic carbon in response to physiographic parameters. However, soil organic matter and organic carbon was significantly influenced by different aspects (p≤0.05). The maximum (8.46 and 55/87 t/ha) and minimum (0.9 and 22/77t/ha) organic carbon and soil organic matter were observed in north-facing and south-facing slope, respectively. Furthermore, there was a positive correlation between soil OC and organic matter and negative correlation with Ph. In order to interpolate soil OC, geostatistical and Classical statistics methods were compared considering RMSE and MAE values following by optimization procedure. The results showed geostatistical methods have lower error and higher accuracy comparing to Classical statistics methods. In summary, simple Co-kriging with organic carbon as auxiliary variable is the most appropriate one for soil organic carbon interpolation in the study area. The results indicate poor spatial distribution and low carbon sequestration in the region due to the degradation of rangelands. The exploitation and overgrazing of livestock is one of the main factors of low carbon storage potential in this basin

The results of statistical analysis in this study show that the soil organic carbon of the region is not affected by the physiographic parameters of the basin, but changes in the amount of organic carbon and soil organic matter were significant compared to changes in slope direction.. Changes in the organic carbon of the area in the slope directions are affected by changes in vegetation and soil depth. Decreased vegetation on the southern slope means the reduced entry of organic carbon into the soil. However, the highest level of organic carbon in the topsoil in the northern slope of the region is estimated at 8.46 tons/hectare, which can be said that the Gonbad watershed is generally poor in terms of organic carbon.

 Soil is one of the main drivers of global warming through losing carbon in the form of CO2. On the other hand, its ability to sequester carbon is a suitable option for reducing CO2 emissions. Therefore, even few changes in carbon sequestration or decomposition of soil organic carbon affect the global atmospheric CO2 content. Although the soils of arid and semi-arid regions have low organic carbon content, they can sequester substantial amounts of carbon due to the large area of these regions. So, the Rothamsted carbon model was used to predict the impact of future climate changes on the amount of CO2 emissions and low soil organic carbon stocks in the semi-arid arable lands of Razavi Khorasan province. This model is one of the most widely used models for the study of soil organic carbon turnover and has been evaluated in a variety of ecosystems including grasslands, forests and croplands and in various climate regions. The RothC model is consists of five conceptual soil carbon pools, four active fractions and a small amount of inert organic matter (IOM) that is resistant to decay. The active pools splits into: Decomposable Plant Material (DPM), Resistant Plant Material (RPM), Microbial Biomass (BIO) and Humified Organic Matter (HUM). This model is able to reveal the effect of soil texture, temperature, rainfall, evaporation, vegetation and crop management on the soil organic carbon turnover process.

 The Rothamsted carbon model was calibrated and validated using data measured in 2020 and available data from the long-term field experiments in the semi-arid agricultural lands of Jolge Rokh. Then, by analyzing the climate change of the study area, the impact of climate change until the end of the current century on the amount of CO2 cumulative emissions, total organic carbon (TOC) and active carbon pools model were modeled and compared in the current climate and also climate change conditions.

 The comparison between the measured and simulated soil organic carbon values by the model shows the potential of the model to provide predictions with acceptable accuracy. The outcome of comparisons revealed that R2, Root Mean Square Error (RMSE), Mean Difference (MD), Mean Absolute Error (MAE) and Model efficiency were 0.97, 2.78, 2.11, 2.33 and 0.70 respectively. Assessment of climate changes in the region (during 1981-2020) showed a decrease in precipitation and a significant increase in temperature over the past 40 years. Climate change simulation was carried out by temperature increasing and decreasing the precipitation until the end of the current century, indicated the decrease of all active carbon pools. It was found that DPM, RPM, BIO, HUM and TOC decreased respectively to 2.41, 2.72, 2.51, 1.04 and 1.32% compared to the current climatic conditions, while the cumulative CO2 emission increased by 1.26%. Temperature rising leads to increase the rate modifying factor (a) by 2.20%, which enhances microbial respiration and decomposition rate of organic carbon and CO2 emissions (carbon output). However, it also increases the ecosystem's net primary productivity (carbon input). Decreases in rainfall and increase in potential evapotranspiration cause a reduction of the rate modifying factor (b) to 0.23%, which on one side reduces the activity of microorganisms and carbon biodegradation; but on the other side, it decreases the vegetation cover and following that reduces CO2 trapping during the photosynthesis process and transfers it to the soil. It seems that in arid and semi-arid climates where the lack of moisture is the most important limiting factor of the plants growth; the role of precipitation in carbon decomposition and sequestration is greater than temperature.

 The Rothamsted carbon model is suitable for regional simulations because it requires only easily obtainable inputs. Therefore RothC is an appropriate tool for estimating long-term effects of climate change and agricultural management (such as application of manures, returning plant residues to the soil, crop rotations, conservation tillage etc.). The RothC model validation in the cold semi-arid agricultural lands of the region, shows the ability of model to properly simulate the pattern of organic carbon changes. Also, simulation of soil organic carbon changes under the climate changes conditions indicates an increase in cumulative CO2 emissions and decrease in soil organic carbon pools of the study area. The methodology can be applied to other regional estimations, provided that the relevant data are available. The predictions allowed to identify the land management potential to carbon sequestration. Such information demonstrate a beneficial tool for evaluation of past land management effects on soil organic carbon trends and also estimation of future climate change effects on soil organic carbon stocks and CO2 emissions.