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Ongoing climate change has been a major global challenge since the 1880s. Sequestration of carbon(C) in rangelands ecosystems could provide a net carbon sink to offset increases in atmospheric C in global scale. This research is aimed at estimating the above-ground biomass carbon sequestration potential in Iran. For this purpose, total rangelands area and productivity data were extracted from the annual reports of Agriculture Statistical Pocketbook (2006-2013) of the country. Then productivity data was used to calculate above-ground C storage per province. The maximum and minimum rangeland areas were observed in Sistan and Baluchestan and Mazandaran (Nowshahr) Provinces, respectively. Maximum above-ground biomass C storage was about 1.07 Mg Cha^-1y^-1 in Fars Province. The minimum amount occurred in Qom province with only 0.023Mg C ha^-1 y^-1. In summary, mean carbon CO₂fixation was about 0.25 Mg C ha^-1 y^-1in Iran’s rangelands from 2003 to 2013. Considering the total rangeland area(≈ 84.8 million hectare) and productivity of Iran, 11770.011 Gg C y^-1 carbon is stored in above-ground biomass annually providing at least 5885 Gg organic C sequestration potential.

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Background: Grazing intensity has a major effect on soil and biomass organic carbon storage (C). Various plants and ecosytems with deiffernt charactristices have their unique responses to the grazing. Recognizing the effects of grazing intensity on C in various envrionments dominated by Halocnemum strobilaceum, such as Incheboron salt land of Golestan province, helps plannig the grazing startegies.
Materials and Methods: Three grazing sites, viz. heavy grazing (in vicinity of resting point), moderate grazing (at a distance of 650 meters from resting point) and light grazing (at a distance of 2050 meters from resting point) were selceted. Sampling of soil and H. strobilaceum species was carried out with systematic-random method in Nov. 2012. In this regard, fifteen plants along the five 100 meters transects (with distance of 30m) were randomly selected and underground and abovegrond organs were extracted. The amount of biomass C was determined by combustion method. Also, soil sampling with five repetation was carried out in two depths (0-20 cm and 20-40 cm) and the amount of stored C was determined by Walkly and Black method.
Results: The sum of underground and aboveground biomass C in light grazing site was more than the heavy and moderate grazing sites, which were about 1.17, 1.07 and 0.567 ton/hectare respectively. The amount of soil C for the mentioned sites were 162.56, 137,39 and 80.76 ton/hectare, respectively. Besides, the depth 0-20 cm in all sites had a higher C. The soil C comprised more than 99 percent of ecosystem total stored C (biomas and soil C) in each site. In terms of total ecosystem C, the heavy and moderate grazing site had about 84.37 and 32.20 ton/hectare less C compred to light grazing site.
Conclusions: From a management perspective, it is concluded that light grazing intesity in saltalnd region can lead to maintenance of C in high level and grazing systems should avoid high stocking rates because it may adversely affect soil C. Heavy grazing has more negative effects on C compared to moderate grazing. Both soil and biomass respond similarly to different grazing intensities. The soil, especially first depth as the main resourcse of C, should be protected from detrioration to prevent C decling. In view point of C sequestration, it is suggested to plan grazing intesity in light level and protect the soil of rangelands.the five 100 meters transects (with distance of 30m) were selected and underground and abovegrond organs were extracted. The amount of biomass C was determined by combustion method. Also, soil sampling with five repetation was carried out on two depths (0-20 cm and 20-40 cm) and the amount of stored C was determined by Walkly and Black method. The results showed that the sum of underground and aboveground biomass C in light grazing site is more than the heavy and moderate grazing sites. This value is about 1.17, 1.07 and 0.567 ton/hectare for light, moderate and heavy grazing, respectively. The amount of soil C for the
and soil C) in each of sites.

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Aims: In recent years, global warming has increased the importance of carbon sequestration. The present study was conducted to survey the effect of banqueting and fire on soil organic carbon (SOC) sequestration in Atbatan rangelands of Bostanabad District.
Materials & Methods: For this purpose, using systematic-random strategy, composite soil samples were taken from fire happened 2 years ago (in 2 aspects of east and west), banqueting constructed 25 years ago (in 2 aspects of north and south), and control sites. The SOC was measured and results were analyzed, using two-way ANOVA.
Findings: On the contrary of interaction effect, the main effects of aspect and fire were significant on SOC. The SOC of the control site with 28.9 t/ha was higher than the fire site with 21.76 t/ha. The average SOC in the eastern aspect was higher than the western aspect as such the average amount of SOC in western and eastern aspects were 28.94 t/ha and 21.72 t/ha, respectively. Banqueting had an increasing significant effect on SOC, as such SOC of the treatment site was 34.47 t/ha compared to the control site with 22.21 t/ha. The SOC in the northern and southern aspects was not significantly different, and the SOC of southern and northern aspects equaled 28.45 t/ha and 28.23 t/ha, respectively.
Conclusion: In conclusion, according to the results of the study, the occurrence of fire in rangelands can reduce the amount of SOC. The rangeland banqueting increases the amount of SOC in both aspects.
 

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Aims: Despite the many studies on carbon stock and sequestration in Iranian forest ecosystems, the effects and role of Mediterranean species on carbon stock in Iranian forest ecosystems are not well known. To our knowledge, no information is available on the carbon sequestration of Mediterranean species in Iran. This study aimed to quantify the surface soil carbon stock of Mediterranean tree species in the Zagros forest. 
Materials & Methods: To this, ten soil samples were taken under the canopy of Cupressus sempervirens var horizontalis, Myrtus commonis, Quercus brantii, and also bare lands from a depth of 0-20 cm. Soil carbon stocks were calculated in each of the studied treatments. One-way ANOVA was used to evaluate the differences among the studied species and bare land for soil physiochemical properties and carbon stock. Multiple linear regression (MLR) using the stepwise method was performed to define the most critical soil factor for soil carbon stock calculation. 
Findings: Our results indicated that Cupressus sempervirens represent the highest significant value for soil carbon stock (237.79 t.ha-1). Soil carbon stock in Myrtus commonis and Quercus brantii stands were 122.05 and 91.90 t.ha-1, respectively. Significant differences between Myrtus commonis and Quercus brantii were recorded. The lowest soil carbon stock was recorded in the control site and was significantly lower (27.26 t.ha-1) compared to the other treatments. Compared to the bare land and Quercus brantii stand, Cupressus sempervirens had 872.30 and 258.74 percent higher soil carbon stock, respectively. The higher soil nutrient content under the Mediterranean canopy is due to the higher soil nutrients available. Also, it might be related to the protection made for these species compared to the oak forest. Moreover, soil organic carbon and bulk density represent the best predictors of the soil carbon stock based on the multi-linear regression method. 
Conclusion: Reforestation/afforestation programs using Myrtus commonis and Cupressus sempervirens should also be considered for carbon sequestration programs in the Zagros forest, where these species could be planted. Moreover, our results demonstrate that using a variety of tree species, primarily Mediterranean species, would be a proper policy for increasing soil carbon stock in the Zagros forest.