Fractionation of Organic Carbon and Stock Measurement in the Sundarbans Mangrove Soils of Bangladesh  

作　　者：Sayada Momotaz Akther Md Mahfuz Islam Md Faruque Hossain Zakia Parveen Sayada Momotaz Akther;Md Mahfuz Islam;Md Faruque Hossain;Zakia Parveen(Department of Soil, Water and Environment, University of Dhaka, Dhaka, Bangladesh;Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695, USA;OSCM, FBA, American International University-Bangladesh, Kuril, Dhaka, Bangladesh)

机构地区：[1]Department of Soil, Water and Environment, University of Dhaka, Dhaka, Bangladesh [2]Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC 27695, USA [3]OSCM, FBA, American International University-Bangladesh, Kuril, Dhaka, Bangladesh

出　　处：《American Journal of Climate Change》2021年第4期561-580,共20页美国气候变化期刊（英文）

摘　　要：Mangrove soils are well known for their high capacity of storing organic carbon (SOC) in various pools;however, a relatively small change in SOC pools could cause significant impacts on greenhouse gas concentrations. Thus, for an in-depth understanding of SOC distribution and stock to predict the role of Sundarbans mangrove in mitigating global warming and greenhouse effects, different extraction methods were employed to fractionate the SOC of Sundarbans soils into cold-water (CWSC) and hot-water (HWSC) soluble, moderately labile (MLF), microbial biomass carbon (MBC), and resistant fractions (RF) using a newly developed modified-method. A significant variation in total SOC (p < 0.001), SOC stock (p < 0.001) and soil bulk density (p < 0.05) at the Sundarbans mangrove forest were observed. In most soils, bulk density increased from the surface to 100 cm depth. The total SOC concentrations were higher in most surface soils and ranged from 1.21% ± 0.02% to 8.19% ± 0.09%. However, C in lower layers may be more resistant than that of upper soils because of differences in compositions, sources and environmental conditions. SOC was predominately associated with the resistant fraction (81% - 97%), followed by MLF (2% - 10%), HWSC (1% - 4%), MBC (~0% - 4%), and CWSC (~0% - 3%). The significant positive correlations between different C fractions suggested that C pools are interdependent and need proper management plans to increase these pools in Sundarbans soils. The SOC stock of the studied areas ranged between 16.75 ± 3.83 to 135.12 ± 28.61 kg·C·m^{<span style="white-space:nowrap;"><span style="white-space:nowrap;">&#8722;</span></span>2} in 1 m soil profile and has an average of 31.80 kg·C·m^{<span style="white-space:nowrap;"><span style="white-space:nowrap;">&#8722;</span></span>2}. The substratum soils had more carbon than the upper layers in the Sundarbans wetland due to burial and preservation of carbon by frequent tidal inundation. A higher SOC stock in the soil profile and its primary associMangrove soils are well known for their high capacity of storing organic carbon (SOC) in various pools;however, a relatively small change in SOC pools could cause significant impacts on greenhouse gas concentrations. Thus, for an in-depth understanding of SOC distribution and stock to predict the role of Sundarbans mangrove in mitigating global warming and greenhouse effects, different extraction methods were employed to fractionate the SOC of Sundarbans soils into cold-water (CWSC) and hot-water (HWSC) soluble, moderately labile (MLF), microbial biomass carbon (MBC), and resistant fractions (RF) using a newly developed modified-method. A significant variation in total SOC (p < 0.001), SOC stock (p < 0.001) and soil bulk density (p < 0.05) at the Sundarbans mangrove forest were observed. In most soils, bulk density increased from the surface to 100 cm depth. The total SOC concentrations were higher in most surface soils and ranged from 1.21% ± 0.02% to 8.19% ± 0.09%. However, C in lower layers may be more resistant than that of upper soils because of differences in compositions, sources and environmental conditions. SOC was predominately associated with the resistant fraction (81% - 97%), followed by MLF (2% - 10%), HWSC (1% - 4%), MBC (~0% - 4%), and CWSC (~0% - 3%). The significant positive correlations between different C fractions suggested that C pools are interdependent and need proper management plans to increase these pools in Sundarbans soils. The SOC stock of the studied areas ranged between 16.75 ± 3.83 to 135.12 ± 28.61 kg·C·m^{<span style="white-space:nowrap;"><span style="white-space:nowrap;">&#8722;</span></span>2} in 1 m soil profile and has an average of 31.80 kg·C·m^{<span style="white-space:nowrap;"><span style="white-space:nowrap;">&#8722;</span></span>2}. The substratum soils had more carbon than the upper layers in the Sundarbans wetland due to burial and preservation of carbon by frequent tidal inundation. A higher SOC stock in the soil profile and its primary associ

关 键 词：Carbon Sequestration Carbon Sink Carbon Source Soil Organic Carbon Stock Sundarbans Mangrove Forest 

分 类 号：S15[农业科学—土壤学]