Soil carbon storage and its economic values of inland wetlands in Korea

Due to the importance of wetlands as a global carbon pool, explicit research on and management of the carbon storage of wetlands have drawn much attention. Within a single climatic zone, South Korea has various types of inland wetlands such as tidal salt marshes, freshwater lakes, rivers and peatlands, thereby providing an excellent platform for scientific investigation to identify patterns and key controlling factors of carbon budget in different inland wetlands. We estimated the amount of soil organic carbon (SOC) of 2444 inland wetlands in South Korea by cluster analysis and Monte-Carlo simulation using data from South Korea's National Wetland Inventory and their economic values by literature review. In addition, we identified key controlling factors that are closely related to SOC of 34 inland wetlands by correlation analysis and ANOVA test. We found that the total SOC stock of inland wetlands in South Korea is 16.3 ± 0.4 TgC (22.3 ± 0.6 kgC m −2 ), which is 5.3–5.5% of the total SOC stock of the country, and the annual carbon sequestration rate is 60.7 ± 9.8 gC m −2 yr −1 . The economic value of the total SOC stock is 2.0 ± 0.1 billion USD (2.8 ± 0.1 USD m −2 ), and that of the annual sequestration rate is 5.5 ± 0.9 million USD yr −1 (7.5 ± 1.2 10 −3 USD m −2 yr −1 ). The mean atmospheric temperature and soil characteristics including water content, total nitrogen and electrical conductivity showed positive correlations with SOC, suggesting the importance of hydrology and water chemistry as key determinants of SOC. In addition, inland wetlands with different dominant plant species showed significantly different SOC, probably because primary production and chemical composition of vegetation are strongly associated with carbon input into wetlands. However, annual precipitation and soil pH showed no correlation with SOC. Our results demonstrate that the carbon budget of inland wetlands in South Korea is considerable, and its economic value is closely related to characteristics of soil and vegetation. • The total SOC stock of inland wetlands in South Korea is 16.3 ± 0.4 TgC (2.0 ± 0.1 billion USD). • The annual carbon sequestration rate of inland wetlands in South Korea is 60.7 ± 9.8 gC m −2 yr −1 (7.5 ± 1.2 10 −3 USD m −2 yr −1 ). • The key controlling factors of inland wetlands' SOC are MAT, soil WC, TN, EC, and dominant plant species.