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Introduction 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. Materials and Methods 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. Results 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. Discussion and ConclusionThe 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.

Introduction 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. Materials and Methods 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. Results 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. Discussion and Conclusion 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. [ABSTRACT FROM AUTHOR]

IntroductionCarbon dioxide gas, produced from fossil fuels in industrial centres and near big cities, has a significant effect on climate change and global warming. Sequestration of carbon in plants and soil of protected areas, especially national natural parks, is the simplest and most economical way to reduce atmospheric carbon dioxide. The National Bamou Park, with an area of 46,913 hectares near the industrial centres of Shiraz, Zarghan, Maroodasht and Abbarik, provided a good chance for carbon sequestration. In this research economic analysis of this park's soil carbon sequestration capability in 2022 was done.Materials and MethodsBased on vegetation cover and geomorphological conditions, 20 and 5 locations inside and outside the park were selected for sampling. Composite soil samples were taken from the 25 profiles with a depth of 30 cm length and width of 20 cm. The Wallcly-Black method was used to determine the percentage of soil organic carbon in the laboratory. The economic evaluation of the sequestered carbon was done using the damage cost avoided method at three levels: low estimate based on the values of trade in the Prototype Carbon Fund, medium estimate based on anticipated values in the future European Union carbon trading scheme and high estimate based on the damage cost assessment made by Intergovernmental Panel on Climate Change.ResultsBased on the results, the average measures of carbon sequestered in the soil of the lands inside and outside the park were 40.05 and 21.75 tons per hectare, respectively. Based on the t-test, the average carbon sequestered inside and outside the park significantly differs at 1%. The average economic value of avoided damage related to carbon sequestration per hectare of land inside the park at low, medium and high levels are 123.12, 410.41 and 3283.26 million rials, respectively. The corresponding amounts outside the park are 66.86, 222.88 and 1783.04 million rials. The average economic value of sequestered carbon in the soil of each hectare of land inside and outside the park, based on the t-test, has a significant difference at the level of 1%.Conclusions and RecommendationsThe suitable conditions of vegetation and soil of Bamou National Park have caused this park to have a high economic value because of the environmental services of carbon sequestration in the soil and absorption of carbon dioxide gas. Thus, it is possible the economic value of such services is considered in financial calculations, and all or part of it is allocated for the protection and expansion of these parks. An important point about the economic value of the parks and forest ecosystems services is the possibility of buying and selling carbon sequestered or carbon dioxide gas emitted into the atmosphere. For this purpose, it is suggested to pay attention to the legal frameworks and necessary infrastructures for creating an applied market of carbon sequestration and carbon dioxide emission at the national and regional levels. In addition, concerning the natural resources of Fars province and the criteria of international climate change agreements, it is possible to use foreign capital to help create and expand national parks and forest ecosystems as greenhouse gas reservoirs. Therefore, it is suggested to use these legal agreements to attract credit from international organizations.

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. [ABSTRACT FROM AUTHOR]

IntroductionEcosystem 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.Materials and MethodsThis 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.Results and DiscussionThe 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.Conclusion 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.AcknowledgmentThe authors gratefully acknowledge the financial support of Gorgan University of Agricultural Sciences and Natural Resources and Dr. Hamid Sakinin for his help.

The carbon sequestration project is being implemented under the support of various international organizations aiming for reducing greenhouse gas emissions across developing countries. Mahalat County is one of the leading regions in Iran to implement this project. Despite the objective achievements, the current project has left many ecological, economic, social and psychological impacts in the study areas. Through a survey research method, the present study analyzed these impacts from the perspective of 105 experts. The results revealed that the sequestration project could significantly reduce the risk of runoff and flooding by implementing watershed management, grazing and desertification operations, and preventing soil erosion to an acceptable extent. By holding six skill-based training courses, the participants' job skills were improved to a desirable level, and simultaneously with the holding of these courses, 5 microcredit funds were also established, which provided the necessary economic support to start 49 businesses. By forming 22 development groups, the group members' social capital was improved to a good extent, especially in the dimension of social trust. In addition, as a result of holding skill-based training courses and organizing villagers into development groups, their attitude and behavior towards natural resources and environment improved. In general, the results indicated that the measures taken in the project had a significant impact on the formation of balanced sustainable development components, as well as achieving the goal of soil carbon sequestration. [ABSTRACT FROM AUTHOR]

Background and objectives: 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. Methodology: 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. Results: 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. Conclusion: 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. [ABSTRACT FROM AUTHOR]

Background and Objectives: 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. Methodology: 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. Results: 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. Conclusion: 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. [ABSTRACT FROM AUTHOR]

Background and Objectives: 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. Methodology: 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. Results: 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. Conclusion: 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. [ABSTRACT FROM AUTHOR]

Introduction 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. Materials and Methods 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. Results and Discussion 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. Conclusion 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.

The use of nuclear techniques can be helpful in the selection and implementation of optimal agronomic practices as well as the provision of appropriate management strategies in soil and water conservation, achieving sustainable development goals. In this study, we investigated the effects of applying wheat and maize crop residue at five rates, including 0, 25, 50, 75, and 100 %, on the dynamics of soil particulate organic matter (POM) and its origin at depths of 0-10 and 10-20 cm under conventional tillage and no-tillage systems were aimed. For this purpose, the natural abundance of carbon-13 (δ13C) technique was used. The results showed that increasing residue rates in the conventional tillage system increased the amount of δ13C at two soil depths of 0-10 and 10-20 cm. In the no-tillage system, increasing residue rates led to an increase of δ13C only for the depth of 0-10 cm, and no significant differences were observed among residue treatments at a depth of 10-20 cm. In addition, the comparison of δ13C values ​​of soil and plant residues of wheat and corn confirmed that the main source of soil particulate organic matter originated from the wheat residue, indicating the more substantial effect of wheat residues on improving soil organic matter than maize.

Introduction Urban development and land use pattern changes strongly affect the ecosystem service of carbon sequestration and storage. To integrate the concept of this climate regulation service into land use issues, we need to have information about its spatio-temporal distribution, so that with the help of mapping and quantification, protection and development sites can be selected with the continued provision of this service by the ecosystem. The current research was conducted with the aim of investigating the process of carbon sequestration and carbon storage ecosystem service changes in the process of urban growth and development and its valuation to improve the spatial planning of the land.Materials and Methods The study area is the coastal strip of Bandar Abbas City with a coastline length of 69 km. To comprehensively conduct the research, the smallest hydrological unit in the region where this city is located was selected which included three sub-watersheds. The total area of the region is equal to 272806 ha. At first, the land cover-land use map for the years 2000 and 2020 was prepared, and the future changes were predicted with different scenarios. Then, using the InVEST carbon storage and sequestration model, spatial distribution and changes in carbon storage and economic value were obtained.Results and Discussion The results showed that the largest area of the study watershed is the barren and range lands, which during the study period have decreased and man-made uses, water levels, and agriculture have increased. Modeling calculations showed the carbon sequestration capacity from 3741321.08 t in 2000 to 3763695.92 t in 2020 with an increase of 22374.82 t positive carbon sequestration. The reason for that was the growth of agricultural lands. Correspondingly, the economic value of this increase in deposition power during the study period was calculated as 874393.08 $.Conclusion It is expected that with the future usage scenarios, the positive growth of sequestration and subsequent financial benefit in terms of carbon sequestration will continue. But various factors can cause changes or disturbances in ecosystems and ultimately in ecological functions, that climate change is one of the most important factors and causes changes in the structure and functioning of ecosystems. As a result, services should be checked depending on climatic factors and land use changes, because the influence of climatic factors creates new states of the possible future situation, and uncertainty of land use scenarios and conflicts between ecosystem services can cause a change in the nature and change in the direction and size of services being provided by the ecosystem. Along with quantification, the economic value of service can provide valuable spatial principles for urban development and environmental awareness.

Introduction Characteristics such as the high levels of agrobiodiversity, the efficiency of the nutrition, and also variety in ecological and socio-economic functions have altered home gardens into the appropriate model for achieving a sustainable agricultural system. So far, fewer studies in relation to these features have been done in home gardens of dry and semi-arid regions. Protection of diversity with a particular emphasis on agricultural biodiversity is fundamental to sustainable development in food production and hence food security. Expansion of industrial agriculture in the form of monoculture for the purpose of maximizing the yield with the aid of high-yielding varieties and intensive use of inputs has hampered the ecological functions of food production systems worldwide. This problem can be overcome by the application of a wide array of ecological agriculture practices, of which food production in home gardens is only one of them. This environmentally sound practice is an old system of land use almost in all parts of the world with a wide range of dimensions. A combination of different plants, from herbs to trees and in cases with poultry and other low-weight animals, provides a complex sustainable system of food production. This type of subsistence food production is based on local knowledge and normally is part of the residential area or, to the, low input. Food produced in this system is consumed locally, and women are the main element in both production and marketing. Exchanges of experience and knowledge, seed, and also tools, and labors are very common in neighboring communities. The purpose of the present study was to investigate the agrobiodiversity of home gardens in an arid environment of Khorasan Razavi Province.Materials and MethodsData collection for this study was based on the fieldwork with the distribution of questioners. For this purpose, 17 villages from 3 highly populated counties of Mashhad/ Quchan and Nyshabour were selected, and 164 questioners were distributed with a face-to-face procedure. After the collection and validation of data, only 136 questionnaires were selected, data were extracted, and finally, an analysis was carried out. Afterward, the Shannon biodiversity index, Simpson index, and species richness were calculated. The amount of carbon sequestered was also calculated by an equation referred to in the literature. For the calculation of biodiversity indices, the area under cultivation of each species was used. Based on the available previous studies, seven basic functions for home gardens were assigned.Results and DiscussionResults showed the highest Shannon index of species diversity equal to 1.88 for the county of Neishabour; however, the highest functional diversity was found in Quchan. More the 79 percent of changes in the Shannon index are caused by changes in species richness. Stepwise regression analysis revealed that changes in species richness, home area, and household population were the factors that caused 84 percent of changes in functional diversity. Home gardens in these three counties sequester 8.1 tons of carbon dioxide per hectare, and this amount showed a decreasing trend where the distance from the vehicle roads was increased.ConclusionIt was revealed that with taking distance from the main roads, the amount of carbon dioxide (kg per m2) decreased by tree species.AcknowledgmentsThe authors acknowledge the financial support of this project (grant number 2/19719) by the Vice President for Research and Technology, Ferdowsi University of Mashhad, Iran.

Background and Objectives: Although occupying a relatively small space and hosting biodiversity hotspots, riparian forests have the potential to sequester more and faster carbon and provide many valuable ecosystem services. They also affect plant biodiversity patterns, soil characteristics and habitat quality. Despite their high environmental and protection values, the riverine forests have received less attention and most of the studies have related to the distribution pattern of species and the characteristics of their soil fauna community. The aim of this study was to investigate the effect of landuse types on the physical, chemical and carbon deposition of the soil profiles along the Karkhe River. Materials and Methods: The effect of various landuses including natural forest, afforestation, agriculture and barren lands on the physical, chemical characteristics and carbon deposition of soil profiles along the Karkhe river was studied. A number of 30 soil samples randomly were collected from each site at a depth of 0-20 cm in the center of each plot. Soil moisture content, texture, specific gravity, pH, electrical conductivity, organic carbon, total nitrogen, absorbable potassium and phosphorus, and calcium carbonate were determined in the laboratory and therefore the amount of carbon deposition was calculated. Data were analyzed using one-way analysis of variance (ANOVA) and SNK test for comparing mean values. All statistical analyzes were performed in SAS 9 software. Results: The results showed significant differences among agricultural use with 18.45% of clay content, natural forest use and agricultural use with 46.29 and 43.92% of silt content, afforestation use and barren use with 60.47 and 56.86% of sand content. Bulk density was increased in forest use. The highest value of electrical conductivity with 3.17 ds.m-1 was observed in barren lands, which reached an increase of 71.35% compared to the natural forest use. In agricultural use, absorbable potassium decreased by 62.04% compared to the natural forest use. According to the results, landuse change has a significant and decreasing effect on the amount of carbon sequestration. The highest amount of carbon sequestration observed in the natural forest with the amount of 63.37 tons per ha, while the lowest carbon storage was related to agricultural use with 41.53 tons per ha. Conclusion: In general, soil properties in riparian forests are of better quality with high carbon deposition, and landuse changes cause damage to these habitats. Studying carbon sequestration in the riparian forests can help determine baseline conditions and can be used to enhance restoration plans or address the impact of climate change on carbon stocks in these ecosystems. [ABSTRACT FROM AUTHOR]

Introduction 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. Materials and Methods 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. Results and Discussion 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. Conclusion 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. [ABSTRACT FROM AUTHOR]

Introduction Urban development and land use pattern changes strongly affect the ecosystem service of carbon sequestration and storage. To integrate the concept of this climate regulation service into land use issues, we need to have information about its spatiotemporal distribution, so that with the help of mapping and quantification, protection and development sites can be selected with the continued provision of this service by the ecosystem. The current research was conducted with the aim of investigating the process of carbon sequestration and carbon storage ecosystem service changes in the process of urban growth and development and its valuation to improve the spatial planning of the land. Materials and Methods The study area is the coastal strip of Bandar Abbas City with a coastline length of 69 km. To comprehensively conduct the research, the smallest hydrological unit in the region where this city is located was selected which included three sub-watersheds. The total area of the region is equal to 272806 ha. At first, the land cover-land use map for the years 2000 and 2020 was prepared, and the future changes were predicted with different scenarios. Then, using the InVEST carbon storage and sequestration model, spatial distribution and changes in carbon storage and economic value were obtained. Results and Discussion The results showed that the largest area of the study watershed is the barren and range lands, which during the study period have decreased and man-made uses, water levels, and agriculture have increased. Modeling calculations showed the carbon sequestration capacity from 3741321.08 t in 2000 to 3763695.92 t in 2020 with an increase of 22374.82 t positive carbon sequestration. The reason for that was the growth of agricultural lands. Correspondingly, the economic value of this increase in deposition power during the study period was calculated as 874393.08 $. Conclusion It is expected that with the future usage scenarios, the positive growth of sequestration and subsequent financial benefit in terms of carbon sequestration will continue. But various factors can cause changes or disturbances in ecosystems and ultimately in ecological functions, that climate change is one of the most important factors and causes changes in the structure and functioning of ecosystems. As a result, services should be checked depending on climatic factors and land use changes, because the influence of climatic factors creates new states of the possible future situation, and uncertainty of land use scenarios and conflicts between ecosystem services can cause a change in the nature and change in the direction and size of services being provided by the ecosystem. Along with quantification, the economic value of service can provide valuable spatial principles for urban development and environmental awareness. [ABSTRACT FROM AUTHOR]

To investigate and compare the carbon sequestration capacity of salt-tolerant plants and to prioritize and introduce them for the restoration of saline lands, Suaeda fruticosa Forssk species. ex J.F.Gmel, Tamarix aphylla (L.) H.Karst, Tamarix leptopetala Bunge, and Alhagi camelorum DC were selected as saline species and Artemisia sieberi Besser species as nonhalophyte species in dry areas. After selecting the South Garmsar site in 2017, the floristic list was determined. Then, at the time of maximum plant growth, ten samples were taken from the aerial, underground, and soil under bushes and between the bushes. After preparation, the samples were transferred to the laboratory of the Research Institute of Forests and Ranges, and the amount of organic carbon in the root and shoot samples and the amount of organic carbon, electrical conductivity, acidity, and texture of the soil samples were determined. The results showed that the average percentage of carbon stored in the shoots and roots of A. camelorum is 86.86%, T. leptopetala is 85.3%, T. aphylla is 81.49%, S. fruticosa is 86.22%, and A. sieberi is 88.83%. Therefore, A. sieberi has the highest carbon storage per unit volume. The average carbon content in the soil under A. camelorum is 0.78%, T. leptopetala is 1.087%, T. aphylla is 0.62%, S. fruticosa is 0.84%, and A. sieberi is 0.55%. According to the results, the production rate of A. camelorum was 58.7 kg/ha, T. leptopetala 160.92 kg/ha, T. aphylla 3573 kg/ha, S. fruticosa 15.25 kg/ha, and A. sieberi 80.1 kg per hectare is estimated. Therefore, under the same ecological conditions, T. aphylla species can absorb and deposit more carbon in space. Accordingly, the amount of carbon deposited in the soil under the A. camelorum plant is 32.9 tons ha -1 and in the soil between the bushes is 32.9 tons ha -1, and the amount of carbon deposited in the soil under the T. leptopetala plant is 41.6 tons ha -1and in the soil between the plants 2.94 tons ha -1, the amount of carbon deposited in the soil under the T. aphylla plant is 22.8 tons ha -1 and in the soil between the plant 2.58 tons ha -1, the amount of carbon deposited in the soil under the plants of S. fruticosa 27.9 tons ha -1 and in the soil between the plants 2.32 tons ha-1and the amount of carbon deposited in the soil of A. sieberi subshrubs was 34.2 tons ha-1and in the soil between the plants, 4.2 tons ha -1 was calculated and estimated. According to the obtained results, the T. aphylla species has the highest amount of carbon deposition due to having the highest production. [ABSTRACT FROM AUTHOR]

Since the development of vegetation is the simplest and cheapest method for excess carbon in the atmosphere, determining the carbon reserve of species will play a role in planning and determining the value of vegetation ecosystem services. In this regard, the main aim of this study was to estimate the amount of carbon sequestration, the economic value of that, and also determine the contribution of each part of organs to accumulate carbon dioxide in two plant species, including Artemisia sieberi and Dorema ammoniacum in the Darebaz Sarayan rangelands, South Khorasan. For this purpose, by sampling the soil and vegetation through the establishment of transects and plots in a random-systematic method, the number of 10 bases of two species, Artemisia sieberi and Dorema ammoniacum, were selected, and the vegetative characteristics and aerial and underground organs of each were completely sampled. The samples were transferred to the laboratory, and carbon deposition conversion coefficient of each plant organ was determined separately by the combustion method. Also, the organic carbon percentage of the soil was measured by the Valky-Black method. In the following, using the method of valuing carbon emission costs and considering the monetary value of 25.3 dollars for each ton of carbon storage, its economic value was determined. The results showed that the total amount of carbon storage in the aerial and underground parts of the D. ammoniacum species is 40.9 and 248.9, respectively. In aerial and underground parts of the plain desert species, it is 1170.9 and 238 tons, respectively. Also, the amount of carbon storage in the soil under cover of A. sieberi and D. ammoniacum was estimated to be 23.13 and 12.38 kg per square meter, respectively, which showed a significant difference compared to the open space (control = 6.29 kg per square meter) (p≤0.01). The rial value of carbon storage for aerial and underground organs in A. sieberi and D. ammoniacum is equal to 8, 1.6, and 0.02, 1.7 billion rials, respectively. The economic value of carbon storage under the canopy of A. sieberi and D. ammoniacum is 26.1 and 14 billion rials for the entire rangeland (with 8732 hectares). Due to the high carbon storage capacity of the A. sieberi species, it is suggested to use this species for restoring the mentioned rangeland and similar rangelands. [ABSTRACT FROM AUTHOR]

Trees are one of the most important carbon reservoirs on the earth and carbon sequestration into plant biomass is an easiest and economically most practical way for mitigating the CO2 from atmosphere. This study aims at determining the biomass and carbon storage in stump and roots of Populus deltoides in Tanian poplar plantations of Guilan province. For this purpose, 15 poplar trees were selected based on selection sampling method 15. After the cutting and moving the logs from the stump to somewhere outside the plantation, excavator machinery (KOMATSU PC 200) was used to remove the stumps and roots from the soil. After separating the stumps and roots, mentioned parts were weighed using a digital scale. In order to estimate the amount of biomass and carbon storage, some samples of various components of poplar trees were then fallen down and weighed. After drying the samples in oven (80 ̊C), the dry weight of the samples was determined. After burning an enough amount of dried samples in the electric kiln, the weight of organic matter and carbon of the stump and root samples were obtained. Results showed that the mean of stump biomass, root biomass, stump and root carbon sequestration for each tree were 2.15, 22.18, 1.05 and 10.94 kg per tree, respectively. Results indicated there was a positive and significant correlation between the biomass and carbon sequestration of stump and root with collar diameter. The amount of carbon storage in the root and stump parts was 3.836 tons per hectare and the economic value of carbon storage was calculated as 46723015.68 Rials per hectare.

In order to explain the ecological-sociological strategy of Tehran land use network/ land cover, the present study was tried to identify the spatial process of the change in the landscape mosaic pattern and its effect on carbon sequestration over the course of 3 decades from 1990 to 2020. In this study, the role of landscape measures in the identification of landscape mosaic spatial pattern changes and its combination with data obtained from ecosystem service modeling was shown. To this end, after examining the process of structural-functional changes in landscape mosaic using decision tree algorithm and InVEST model, the complexity of the relationship between landscape spatial pattern and the quantity of carbon sequestration regulatory services at the two levels of class and landscape was addressed using the measures and data obtained from InVEST model. The findings indicated that the volume of carbon sequestration regulatory services in all periods had reduced due to the effects of the spatial process of “accumulation” in construction strains. Moreover, in the 1990-2020 period, the highest rate of carbon storage loss (291656 tones, 9.58%) occurred due to the effects of the spatial processes of “deletion” in green lands and “fragmentation” in barren lands. In the 2000-2010 and 2010-2020 periods, the volume of carbon storage reduction were 182209 (6.62%) and 159688 (6.22%) tones, respectively. Pertaining to this discussion was the finding that the effect of the change in the index of strain numbers in green and barren lands for all periods was accompanied by increased fineness, which indicates its reverse relationship with carbon sequestration rate. On the other hand, the reduction of other measures in green and barren lands reveals the existence of a direct relationship with the loss of a volume of carbon sequestration in the foregoing period. At the landscape level, the reduction of heterogeneity and simplification of the landscape mosaic spatial pattern led to the reduction of carbon sequestration. From this perspective, it is necessary to prioritize the identification of the spatial processes effective on the landscape structure model in the completion of the processes of the evaluation of the urban development effects on the carbon sequestration service current. [ABSTRACT FROM AUTHOR]

Haloxylonplanting and developing artificial forests in arid lands is one of the important actions to combat desertification. In this research, tree planting (by Haloxylon aphyllum Iljin) in Dosangi Meybod in different methods including repairing, runoff control, pitting and planting in owed have been compared with control area. For this purpose, in each area, four 300 m transects were considered randomly - systematically, and 15 plots (10 m2) were randomly collected on each transect. In each plot, vegetation characteristics including total vegetation percentage, density, canopy cover, freshness and depth of root and soil characteristics including moisture, permeability and soil carbon storage were measured. The Shapiro-Wilk test were used to test of normality of the collected data, and were analyzed using one-way analysis of variance and Duncan's test. According to the results of analysis of variance, the effect of planting with different methods on crown cover, density, freshness and deep rooting of Haloxylon shrubs and the percentage of vegetation is significant at 1% level. However, its effect on permeability and soil moisture in May is significant at 1% level and on carbon storage is significant at 5% level. Increase of vegetation cover by 5.1%, density of 249.7 number per hectare, Haloxylon cover of 3.7%, freshness class 1.5, soil moisture in spring 38.1% rooting more than 3 m and permeability 8.03 cm/h was related to the planting in dry river, which had a relative success in vegetation development in this region.

Given the various advantages of applying conservation tillage methods in the agriculture, including reducing the effects of climate change by decreasing the carbon dioxide emissions to the atmosphere caused by carbon sequestration in soil, this study was conducted with two wheat-cotton and wheat-sesame rotations at Agricultural Research Station Bakhtajerd, in Darab, the southeast of Fars Province, which had a warm and dry climate; this work was carried out in a loam soil during four years. The aim of this investigation was to compare the carbon sequestration (CS) in the soil after application of different conservation tillage methods with the conventional method. The results showed that in wheat-cotton rotation, the maximum and minimum amount of CS in the 0-20 cm depth of soil with the average 17.160 and 13.810 t/ha could be obtained by using no-till and conventional tillage, respectively. Therefore, no-till increased CS by 24.26% in wheat and cotton cultivation, as compared to the conventional tillage. The economic value of this CS increment for the environment was $2459 per hectare. In the wheat-sesame rotation, the highest and lowest CS was obtained with an average of 25.850 and 12.505 t/ha in no-till and conventional tillage, respectively. Namely, direct seeding of wheat and sesame increased the CS at the 0-20 cm depth of soil by 107%, as compared to the conventional tillage with the economic value of $9809.5 per hectare. Under similar conditions, in wheat-cotton and wheat-sesame rotations, the conventional methods could be replaced by no tillage.

Carbon sequestration through trees is one of the most important strategies to mitigate the carbon emission. The present study was conducted in Khorramabad Agricultural Orchard as randomized complete block design. In each experimental unit, three five-year-old trees were investigated in two groups and 12 poplar colonies or cultivars in three replications. Duncan multiple range test was used to find the mean comparison of the treatments and T test was applied to observe the differences between two groups. The results showed that there is a significant difference in the increment rate and amount of carbon sequestration in the two poplar groups (P

Carbon sequestration (CS) in soils is a phenomenon consistent with the principles of sustainable development. Further, it is a vital solution for reducing the atmospheric CO2 and other GHGs. To identify the role of spate irrigation (SI) of afforested plots and rangeland in CS, 36 soil samples were collected from the 0–30 cm top soil in different spate-irrigated and control treatments in November 2017. Organic carbon (OC) was measured by the standard laboratory procedures, and then converted to the sequestered soil carbon (SOC). The data were analyzed using the randomized complete block design benefitting from the SAS software. The means were compared with the Duncan test at P2; this amounts to 4.6 tons of CO2 per year on average.The total income from the carbon rent of the dense Eucalyptus camaldulensis Dehnh. aforested plots at the Kowsar Station is $32381.00 per hectare with an annual mean of $925.17 per hectare.

Primary production is a key indicator in the evalution of aquatic ecosystems that can directly affect carbon sequestration. Due to climate change and environmental dynamics, this component has changed spatially and temporally in different ecosystems. Therefore, to understand and monitor these changes, the most important influential parameters include; sea surface temperature, chlorophyll-a and algal bloom on this component and their changes were analyzed based on the time series. Images related to Chl-a, SST and NPP from January 2003 to December 2018 were used by MODIS sensor and VGPM model to estimate NPP in the study area. Aftar pre-processing and extracting the time series algorithm, the trend of variation was determined using the mann-kendall and theil-sen procedure. Then, using enhancing false color composite, algal blooms in the Persian Gulf and the sea of Oman were identified and the amount of chl-a concentration in the algal bloom area and outside the area was determined. The results of trend analysis with theil-sen procedure showed that the rate of change for chl-a is decreasing in all regions except the fifth region. The highest amount was observed in the fifth region (-0.19), which corresponded to the rate of NPP. The results also show that the highest amount of NPP in the first region in March and the lowest in June and July (540 and 690 gC/m2/day), which corresponds to the amount of chl-a concentration. Despite the apparent correlation, there is no cause-and-effect relationship between SST and chl-a as well as chl-a and NPP. In this way, factors other than chl-a can be considered for algal bloom and NPP. [ABSTRACT FROM AUTHOR]

The aim of this study was to discover the Obstacles of local community’s participation in biological restoration and desertification control plans in the Lapui County, Fars Province. The study is an applied research in terms of purpose, a survey study in terms of collecting data, a field study in terms of controlling variables, and a exploration study in terms of research method. The statistical population of the study consisted of 600 active households of Sustainable Development Cooperative in the Lapui County. Using the Morgan's and Krejcy's tables, the sample size was determined to 234 households. The data gathering tool was a questionnaire whose validity had been confirmed by a panel of experts, and its reliability was confirmed by the Cronbach's alpha coefficient (α > 0.7). The data analysis was conducted by using the SPSS18 and AMOS software. In order to analyze the results, in descriptive section, the centrality (mean and mode), and the dispersion (range of variations, variance, and standard deviation) statistics were calculated, and for the inferential part of the analysis, an exploratory factor analysis was used to factorize the barriers. Results indicated that the most important barriers to participation of local communities in the carbon sequestration project can be identified in six categories: lack of mutual trust and belief, lack of awareness and information channels, administrative and institutional barriers, the implementation barriers, lack of government support, and lack of community needs assessment and satisfaction, which explained a sum of 83.36% of the total variance. The credibility of these barriers was also confirmed by the confirmatory factor analysis.

Given the various advantages of applying conservation tillage methods in the agriculture, including reducing the effects of climate change by decreasing the carbon dioxide emissions to the atmosphere caused by carbon sequestration in soil, this study was conducted with two wheat-cotton and wheat-sesame rotations at Agricultural Research Station Bakhtajerd, in Darab, the southeast of Fars Province, which had a warm and dry climate; this work was carried out in a loam soil during four years. The aim of this investigation was to compare the carbon sequestration (CS) in the soil after application of different conservation tillage methods with the conventional method. The results showed that in wheatcotton rotation, the maximum and minimum amount of CS in the 0-20 cm depth of soil with the average 17.160 and 13.810 t/ha could be obtained by using no-till and conventional tillage, respectively. Therefore, no-till increased CS by 24.26% in wheat and cotton cultivation, as compared to the conventional tillage. The economic value of this CS increment for the environment was $2459 per hectare. In the wheat-sesame rotation, the highest and lowest CS was obtained with an average of 25.850 and 12.505 t/ha in no-till and conventional tillage, respectively. Namely, direct seeding of wheat and sesame increased the CS at the 0-20 cm depth of soil by 107%, as compared to the conventional tillage with the economic value of $9809.5 per hectare. Under similar conditions, in wheat-cotton and wheat-sesame rotations, the conventional methods could be replaced by no tillage. [ABSTRACT FROM AUTHOR]

Several benefits that humans get from ecosystems are called ecosystem services. Carbon sequestration as an eco-regulation service is declining, due to the transformation and destruction of the earth used to recompense the burgeoning human needs for development. In the present study, a pilot landscape of hyrcanian forests, protected area in Jahannama was selected. By examining the land use / cover changes during 2001 to 2018, future condition of the land will be set to determine the carbon storage and carbon sequestration model in 2036. The amount of carbon in the four carbon storage sources including biomass, underground biomass, soil and organic matter along with IPCC reports facilities, field studies and sampling was extracted. Deterioration trend in forest lands and grassland with remarkable role in carbon sequestration was sharpened. The reduction trend will be predicted to reach as much as 40 per cent which will be equivalent to 400859 tons per land. With the same rate in land deterioration, a considerable decrease in ecosystem storage and carbon sequestration’ potentiality will be expected present study indicated that the integration of the concept of the ecosystem services in land planning discourse and land use management via the provision of spatial maps of ecosystem services on a regional scale, along with the rational development of human use, ecological hazards should be minimized, as a result better decision will be made in planning the land. It is also suggested that to enhance the quality of Jahannama ecosystem services in development plans and review within the protected boundaries and the principled management of land use within the protective boundaries. [ABSTRACT FROM AUTHOR]

After 20 years, the effects of five plantations of Acer velutinum Boiss., Cryptomaria japonica D. Don., Cupressus sempervirens L. var. horizontalis (Mill.) Gord., Pinus taeda L.and mixed stand on soil fertility and quality of the stands were investigated and compared with natural forest to determine the appropriate species for planting in low land of Hyrcanian forests. Five 400 m2 plots were selected randomly- systematic in each stand. Quantitative and qualitative characteristics were recorded. Also, within each plot soil in 0-15, 15-30 and 30-45 cm depths were sampled. The results showed significant effect of reforestation on pH, EC, bulk density, organic carbon, total nitrogen, phosphorus and carbon sequestration in the soil. According to the result, P. taedahas the highest pH (4/6) while A. velutinum has the lowest pH (5.5), natural forest stand has the highest (18/0 ds/m) whereas C. japonica has the lowest (06/0 ds/m) EC. Pinus taeda has the highest organic carbon content (1.29%) and total nitrogen (0.36%) but the natural forest has the lowest amount of organic carbon (1.03%) and total nitrogen (0.08%). The mixed stand has the highest phosphorus (1.9 g/kg) and C. japonica has the lowest one (1.8 g/kg). The A. velutinum has the greatest (292830 Mg/ha) while the natural forest has the lowest (223920 Mg/ha) amount of carbon sequestration. The results showed the conifer stands have been more successful in terms of tree quality characteristic while broadleaf stands were more successful in the quantitative characteristic. Finally, it can be claimed that broadleaves stands were more successful in compare with conifer stands.

Large ecosystems such as forests with large amounts of biomass play important roles in carbon sequestration, mitigation of CO2 emissions and human life. The present study aimed at estimating the amount of carbon storage in four land use systems (intact, protected, exploited and garden) in northern Zagros forests, western Azarbaijan province. Within each land use in the same unit, 30 sample plots were established and some quantitative characteristics, such as diameter of all trees with DBH > 10 cm were measured. Total height of largest DBH, tree closest to the center of the plot, diameter of crown along two perpendicular directions and the thickest closest tree in each plot were also measured. The litter samples were taken based on direct sampling in 0.5*0.5 m sample plots at the center and four corners of the plot. The results showed the total biomass in intact, protected, exploited and garden land uses were 450.12, 54.95, 12.85, and 5.38 tons per hectare, respectively. The amount of carbon stored in the land uses were 258.15, 35.52, 9.49 and 3.48 tons per hectare in in intact, protected, exploited and garden land uses, respectively. The results of Duncan test also showed there are significant differences in biomass and carbon storage among different land uses.

This study was carried out to model the soil carbon sequestration changes regarding to soil physical and chemical properties in pure and mixed stands of Eldar pine (Pinus eldarica Medw.) and black locust (Robinia pseudoacacia L.) planted in Semnan Sokan forest park. Four different treatments including pure Eldar pine, pure black locust, mixed of these species and control (without any plant cover) were considered. Soil samples were taken from different soil depth (0-5, 5-10, 10-20, and 20-30 cm) in the treatments and transported to laboratory for further analysis. The results showed that the Eldar pine trees decreased soil acidity and increased aggregates stability of soil. Black locust increased organic matter content, phosphorus, potassium, and nitrogen content of soil which can improve the quality of poor soils of this area. The mixed treatments affect soil properties partly between two above mentioned treatments. The carbon sequestration for Robinia, Pine, mixed and control treatments were 28.67, 18.74, 24.05 and 1.73 tons per hectare, respectively.The modeling of carbon sequestration with physical and chemical properties of soil, the nitrogen and phosphorus were determined as the most important effecting factors on the soil carbon sequestration. Therefore, increasing soil nitrogen in such regions via biological methods (planting nitrogen fixing plants) can play important role in success of afforestion and carbon sequestration projects in such regions.

The certainty of forest resources evaluation regarding to emission of atmospheric carbon dioxide could be increased by estimating the organic carbon pool of forest floor. This research aims at exploring the relationship between plant diversity in the different stories pertaining to forest physical characteristics, and variation of carbon sinks of forest floor. The current research was done in control compartment located in the third district of Glandroud forests. The sample plots with 400 m2 area were sytemetically established in the study area which were separated by a distance of 100 m from each other. Four 1 m2 and 50 × 50 cm2 plots were marked at the center and corners of the sampling plot to measure and collect the herbal plants and litter, respectively. 80 g of each herbal and litter sample was separated after weighing in the field and the all samples were oven-dried at 65ºC for 48 hours. Carbon content of each sample was measured and calculated by placing each sample in the heat oven. The results showed that the tree diversity indices are independent of physiographic changes in the studied forest. However, abundance and dominance of herbal coverage were significantly different at altitude and aspect classification, respectively. Among all the studied carbon sinks, carbon sequestration of litter was significantly different at slope classification. The final result indicated that there was no significant correlation between plant biodiversity and amount of carbon sink in grass coverage. In other hand, the significant correlation was found between carbon stock of litter and indices of Shannon, richness, and importance value of tree storey.

Biomass and carbon sequestration potential is one of the most important benefits of trees in forest ecosystems. This research was done to estimate the amount of biomass in individuals and coppice forms of Quercus brantii Lindl. in Balootboland forests near the Dehdez, Khozestan province. Grid dimensions were selected 100 × 100 m and the nearest tree to a sampling point was chosen. Selected trees should include all diameter classes of high forest or individual trees and all crown diameter classes of coppice if possible. Totally 18 individuals were selected and their quantitative parameters were recorded. Cutting and separating operations were then performed. Different parts of trees were immediately weighted after cutting in the field and sampling was performed to measure the dry weight and the amount of carbon sequestration. According to the results, there was no statistically significant difference between the biomass in two forms of growths. The average biomass of above ground for each tree was approximately determined 277kg and 230kg in form of individual tree and coppice, respectively. These amounts in the stands for individual and coppice forms were estimated 18.2 and 9.3 tons per hectare, respectively. According to the results, large organs (trunk and branches) and small parts (twigs and stump) have more carbon sequestration potential in individual and coppice forms, respectively. The highest and lowest amount of carbon was stored in branches and leaves, respectively.

Modelling allometric equations for saplings of hybrid poplar clone produce a highly accurate estimate of pure productivity and C sequestration, leading to better sales and determination of the capacity of cellulose resources and bio-energy pools. Twenty five cuttings with 25 cm length were planted within a 1×1 m2 area in the Talookola nursery, Sari, in 2011. Ten saplings were selected from the two diameter classes (0-1, 1.1-2 cm). After separating the roots and stems, they were oven-dried at 85ºC for 48 hours. According to the diameter distribution, 24 and 6 saplings, respectively, from each diameter class were uprooted. Collar diameter and height were the twe variables used to model allometric equations. Carbon factor was obtained directly by exposing the wood samples in the oven and was estimated based on organic carbon to organic material ratio. Collar diameter and height were the variables to model allometric equations. The results of allometric modelling showed that multivariate linear model including natural logarithm of diameter, logarithm of height and diameter logarithm square with mean C factor of [C] = 0.44 is the optimal equation (R2adj = 0.732 CF = 1.056) for C sequestration of superior saplings.

Soil organic carbon pools (SOCP) in forests play important roles in terms of biomass productivity level as well as mitigating the climate change effects. Land-use changes cause a potential loss of SOCPs in the forest. Hence, variation of SOCPs around the forest-paddy field transition zone in northern Iran was the main aim of this study. The study was conducted within the natural forest park forest of Nour in Mazandaran province, in which the weak drainage and long periods of soil waterlogging during the rainy season are considered as crucial threats. In two remnant forest fragments with similar stand type (Maple-Ironwood), extend (10 ha) and location (adjacent to the paddy fields), soil samples were collected from two depths of 0- 20 and 20-40 cm at five distances from the farm edge into the inner forest (10 m in the paddy field and 0–10, 30–40, 70–80 and 100–110 m towards the forest interior). All the samples were collected near to the dominant Acer velutinum trees, with a minimum distance of 10 m to each other. In addition, light intensity was measured based on v per m2 in the growing season by photo-light meter measuring device in constant vertical distance from the ground. The result of paired t-test showed significantly higher carbon budget in upper soil depth compared to the lower depth in both forest and paddy fields (P < 0.01). The result of one-way ANOVA indicated no significant differences among different distances to the forest stands (P>0.05). Surprisingly we observed no significant difference between the SOCPs in forest and paddy field. Besides, a significant inverse Pearson’s correlation between light intensity and SOCP was only observed for the upper soil depth in forest and paddy field (r=-0.37, P < 0.05).

The potential for carbon sequestration was evaluated for two coniferous species (Cupressus arizonica Green var. arizonica and Pinus eldarica Medw) in 17-18 year old plantations of Zob-e-Ahan industrial company near Isfahan. Transect sampling was conducted in each section, and five trees in each of the available 5 diameter classes were randomly selected and cut. Moreover, soil samples from 0 to 30 and 30 to 60 cm depth were collected in each part. Shoots and roots of the trees were separately collected and weighted. In addition, carbon sequestration of organs and soil was determined with an in-situ combustion method. Results showed that the rate of carbon sequestration was significantly different between two species (p

The increasing concern on global warming and climate change has resulted in a special awareness to the potential of forest and soil for sustainable carbon sequestration. Therefore, an optimal management of afforestation established in barren lands notably influences the soil carbon sequestration which consequently turns the forest coverage (and underlying soil) to a major organic carbon sink. This study aims to quantify the amount of carbon storage in a selected area afforested Black Locust in Malayer, Iran. Initially, the land units including Black Locust trees were indicated on map polygons, followed by the measurement of all trees within the polygons. Then, five samples in each diameter class were selected, within which the amount of biomass, carbon storage and co2 uptake were estimated. To determine the amount of stored carbon in the soil, samples were collected from two soil depths of 0-10 and 10-30 cm. The amount of the annual sequestrated carbon in biomass and soil was then estimated to be 0.351 and 1.253 tons per ha, respectively. In addition, the annual co2 uptake was 5.87 tons per ha. The results indicate significant differences between the amount of carbon storage in different diameter classes of R. pseudoacacia trees.

Climate change and global warming result in an increased amount of greenhouse gases and, therefore, are amongst the most important challenges for sustainable development. The increment in the amount of Carbon sequestrated as plant biomass as well as within the underlying soils is considered as the easiest way to reduce the atmospheric carbon, which can also be economically implemented. In this regard, urban forests play an essential role in the major cities by absorbing the atmospheric carbon. Here, the existing Pinus eldarica stands planted in Bakhtiardasht forest park of Isfahan were studied for their level of carbon sequestration. To perform the estimation, the biomass, soil (in depths of 0-15cm and 15-30cm) and litter were sampled in a randomly systematic design. The Carbon sequestration in plant biomass and the soil organic carbon were measured by means of allometric equation and Walkly-Black method, respectively. The results indicated that the Pinus eldarica plantation led to an increasing amount of sequestrated Carbon up to 422.4 tons per hectare as compared with the surrounding barren land. The economic value of the resulted Carbon across the entire plantation area was valuated to exceed 5 million USD. The fixed carbon was shown to be mostly stem from the trunk of trees (40 percent). This study concludes such Carbon sequestration to be amongst the essential requirements for existing and upcoming forest conservation plans as an effective step to decrease of atmospheric carbon and mitigate the climate change effects.

Carbon sequestration into plant biomass is an easiest and economically most practical way for dropping off CO2 from atmosphere. The current study was made for four poplar species, consisting of two natives (Populus alba and P. nigra) and two exotics (P. alba×euphratica and P. euphratica× alba), planted at Boldaji Experimental Station in province of Charmahal and Bakhtiari of I.R. Iran. Tree sampling was made randomly (10 trees for each species). After measuring the tree's characteristics including diameter at breast height (dbh), total height and crown diameter, they were felled down to measure the dry weight of different organs, including: (whole tree, trunk, main branches, twigs, leaf and bark of twigs and branches). The regression analysis was applied to find out relationships between mass production and poplar characteristics and to develop different allometry models between different organs and their carbon sequestration ability. The results showed that there are significant correlations to predict biomass for the whole tree's organs at each species. The independent dbh values, in Populus alba and P. alba×euphratica demonstrated high correlation against all the dependent variables (R2=0.95). On the other hand, the main trunk weight was significantly correlated to bark weight (R2=0.86), showed high accurate models. In P. nigra and P. euphratica × P. alba, due to forked stems, dbh didn’t prove any correlation with the tree's characteristics. At the same species, on the other hand, crown diameter was correlated to carbon sequestrated amount on all portions of the trees (R2=0.88). The research showed also significant priority of woody organs in comparison to leaf and twigs, when the prediction of the carbon storage is scheduled.

This research investigates the carbon sequestration potential for Pistachio atlantica Desf in Firuzabad Pistacia and amygdalus forest research inFarsprovince. Using Random-systematic inventory for determining the number of trees in 5-cm diameter classes, 3 trees were selected in each diameter class, they were cut and trunk, branches, leaves and litter were weighted separately. Samples were transferred to laboratory. Organic carbon and its conversion ratio were measured. In order to estimate the organic carbon storage in soil, samples were randomly taken in aspects and flat terrains. Their contents were compared with control samples. The results showed that carbon sequestration potential for Pistasia atlantica Desf is 1.99 tons per hectare and 18654.3 tons in total. Soil carbon storage is 12.78 tons per hectare.Duncantest showed that there is a significant difference among the tree components (p

Vegetation has a major impact on carbon sequestration and soil quality. In order to assess the effect of vegetation type on soil attributes, two different plantation of pure Bald Cypress (Taxodium distichum) and mixed Alder (Alnus subcordata) with Poplar (Populus deltoides) were selected in Safrabasteh Poplar Research Station, Guilan province. In each site morphological, physical and chemical soil properties were studied and compared with each other. The results showed that wet aggregate stability measured as mean weight diameter, bulk density and saturated hydraulic conductivity were significantly different between the two sites. The wet aggregate stability and soil hydraulic conductivity were significantly higher in soil of bald cypress stand compared to soil of alder and poplar stand. The soil with bald cypress stand had more organic carbon and lower bulk density compared to the soil with alder and poplar stand. The organic carbon content had a positive correlation with size of aggregates and a negative correlation with CaCO3 content of soils. The highest concentration of carbon was measured for aggregates with diameter greater than 6 mm. In contrast, aggregates with diameter of 0.25-0.6 mm had the highest concentration of CaCO3. The organic carbon contents of organic and mineral layers for soil with poplar and alder stand were 112.5 and 85.73 ton/ha and for soil with bald cypress stand were 123.08 and 102.97 ton/ha, respectively. The findings of this research indicate that vegetation cover has major impact on carbon sequestration and thereby controls quality indicators of soils. Bald cypress accumulated significantly more organic carbon in soil compared to the mixed alder and poplar stand.

Emission of carbon dioxide via human activities is known as the main cause of global warming. Appropriate forest management practices can have effective role to mitigate carbon emission as well as adsorb atmospheric carbon. The present research was carried out to investigate the effect of 35 years old Common ash (Fraxinus excelsior L.), Chestnut-leaved Oak (Quercus castaneifolia C.A.Mey), Norway spruce (Picea abies L. Krast) and Black pine (Pinus nigra Arn.) plantations on soil carbon sequestration in Dehmian plantation. Systematic soil sampling was done randomly. Totally 54 soil samples were taken from the top soil layers (0 – 10 and 10 – 20cm depths) in four plantations. Soil texture, pH, bulk density, electrical conductivity, organic carbon and total nitrogen were measured in the laboratory. Analysis of variance indicated that the amount of soil carbon sequestration of softwood plantations stands increased in comparison with hardwood ones. Results showed that the amount of soil carbon sequestration in Norway spruce stand (124.27 ton/ha) was significantly (P

One of the most important principles of clean development management (CDM) is to maintain or increase organic carbon pool in the natural ecosystems. As keeping the biodiversity is one of the prominent criteria of sustainable development, this study was conducted to study the relationship between the amount of carbon sequestration and plant biodiversity in the natural stands of Alder-Ironwood (AI), Maple- Ironwood (MI) and Elm-Hornbeam (EH) in the Noor Forest Park, Mazandaran province. The main purpose was to see if variation of plant biodiversity represents the optimal monitoring of soil carbon stock in the studied forest. The common diversity indices related to the different plant storeys were calculated in the random distributed plots with 400 m2 and five repetitions in each stand. Furthermore, the 0- 20 and 20 – 40 cm soil depths were sampled in each stand to measure carbon factor. The results showed significant differences amongst the plant biodiversity indices of the studied stands. Only the index of species richness and species dominance of tree storey was not significantly different among the stands. As such, the findings showed that the AI stand had significantly less soil carbon stock in different soil layers compared to other stands; however, the soil organic carbon was significantly higher in the different soil depths in the MI stand. The results of Pearson’s correlation test showed a significant relationship between tree species dominance and mineral layer of soil carbon stock, implying that density and dispersion of dominant tree species in the stands prominently affect the carbon stock of the soil mineral layer. As such, the following results indicated that potential level of carbon pool of soil organic and mineral layers are significantly correlated with the abundance and evenness of herbal storey. Therefore, coverage and distribution of herbal species in the studied forest can be considered to represent the carbon pool weight in the different soil horizons.

The commercial bole of trees in the mixed-beech forests contributes the majority of biomass and of carbon pool, and is associated with the majority of monetary values in the Hyrcanian forests of Iran. This research aims to accurately predict commercial biomass compared to the allometric equations and field measurements in the third district of Glandroud forests in Noor. After harvesting of the trees, each part of the bole was weighed in the field and wood pieces were extracted from each part. The pieces were then oven-dried, on which the specific wood density was measured. Biomass was simulated by artificial neural network (ANN) including the FFBP network. Allometric equations (logarithmic multiple linear regressions and transformed power function models) with different parameters were examined to study the simulation uncertainty. Diameter at breast height, commercial height and specific wood density (WD) were inputs to the allometric functions and ANN simulation. Architectures of different topology of studied network including transfer functions of Log-sigmoid and Tan-sigmoid with variety of hidden layers and neuron members returned different error estimations of forest commercial biomass. Diameter was one of the most effective factors to predict biomass using ANN. Moreover, increasing height and WD in the ANN reduced the uncertainty of simulation outputs. Adding height and WD with the different combinations in the allometric models increased the accuracy of response variable prediction. The root mean squared errors (RMSE) showed that although there was slight differences in the estimation accuracies of ANN and allometric models, the optimal ANN outputs were of lower uncertainty to spatially predict the response

Drought and environmental crisis caused by climate change are amongst the most crucial challenges in Iran. Due to the essential importance of absorbing CO2, the most crucial factor of global warming, in forest ecosystems, accurate estimation of carbon sequestration in different parts of the trees is of high significance for forest planning and management under climate change scenarios. In this study, 20 velvet maple (Acer velutinum Boiss.) individuals distributed in different diameter classes were initially felled and divided into separate parts of bole and crown. The specific wood density and carbon factor of each fraction and their product were directly calculated and used for non-destructive method to estimate above-ground carbon sequestration (AGC). Allometric equations were developed by weighing of harvested tree parts and measuring each section’s drought coefficient. The ANOVA revealed no tree-specific significant difference among carbon factors. However, the specific wood density was significantly different among the each part of tree individuals. Allometric models showed that the highest accuracy of AGC (R2adj = 0.98, RMS = 0.101, CF = 1.05) was achieved by the exponential model considered re-conversional equation that included DBH and crown diameter. The result of paired t-test showed that the non-destructive estimation method was associated with the highest uncertainty with the low confidence (S% = 318.4, t = -3.5). However, the result of paired t-test between the observations and predictions of the optimal allometric model here showed that the aforementioned model estimation was confident (S% = 22.6, t = 1.36).

Carbon sequestration in different organs such as seed is one of the most important benefits of trees at forest ecosystems. Allocation of carbon within different tree organs is a key process in Carbon cycle. The amount of carbon at each organ, defines its residence time at ecosystem and its cycling. Acorn is important in different aspects at Zagross forests. In addition to its medical, ecological and nutritional value, the seeds have a special importance in terms of carbon sequestration and biomass production. In trial which was carried out in Chaharmahal Va Bakhtiari province of I.R. Iran, 35 individual trees of Quercus brantti Lindl. Were chosen randomly at standard and coppice forests and their quantitative characteristics were measured. After that, the acorns of the trees were harvested separately and the total wet weights was measured at field. The acorn’s dry weight, carbon deposit and nutrition elements were identified in laboratory. The results indicated that the acorn biomass of the standard trees was six times more than the coppice ones and its carbon deposit was 40% of its dry weight. Allometric models were created for the standard and coppice trees. The results of the regression models showed that the average crown diameter developed better equation with the modeling parameters of the standard trees than the coppice ones, whereas in the coppice trees, the best equation was developed by power regression model, based on shoots total height. Overall, there was several precise and suitable allometic models for acorn’s seed biomass and carbon deposit.

Regarding to the importance of forest in carbon sequestration, this study attempted to investigate the carbon storage potential and CO2 uptake in a coppice oak stand. An area of 278 ha of Khalkhal forest located in Ardebil province, north of Iran was selected as the study area. After combining slope, aspect and hypsometric maps, 63 land units (polygons) as well as their area were determined. Then 60 sample trees were selected in such a way that all environmental and typological conditions were taken into account. After determining the fresh weight of different parts of trees in the field, their dry weight and biomass was determined after drying in the kiln. The humus was collected and weighted from an area of 400 cm2under canopy of each tree. To determine the organic carbon content of the biomass, ash content was deduced from dry biomass. To determine the amount of stored carbon in soil, samples were collected from 0-10 and 10-30 cm soil depths. The amount of annual sequestrated carbon in biomass and soil was estimated as 1.51 and 0.1 tons per hectare, respectively. The annual carbon dioxide uptake was 5.94 tons per ha.

This research was aimed to studying the stocking volume and effects of species mixture and forest type on carbon sequestration in watershed No. 45 of Hyrcanian forest. In order to take soil samples, one soil profile was dug in each district as control profile, and then soil sampling was done in recognized forest types by Auger. Due to varying forest type in each district, a total of 11 soil profiles were dug and 288 samples were taken by auger. Soil samples were delivered to soil lab after being dried. Walcky-Black procedure was used for carbon measurement in mineral horizons and in order to evaluate the carbon in humus horizons, burning in oven with 400Oc was applied. The results showed that there is significant difference between Deldareh and Tooskachal districts in term of the amount of carbon sequestration. Over 283 ton/ha carbon sequestration in Deldareh shows that this forest ecosystem is active. Compared to other districts, Deldareh with 312 m3/ha has the highest stocking volume. There is a direct relationship between volume per hectare and forest biomass, contributing more carbon storage. Species composition and mixture in different types in Deldareh distinguish this district from others, which is an important factor of increasing carbon storage potential in mineral horizons. Determining the depth of sampling in mineral layers for quantifying carbon sequestration is another result in this study. As there was not significant difference between 50 to100 cm depths in amount of carbon sequestration in the 11 samples of this study, one can conclude that study of carbon in depth of 50 cm could be sufficient.