乐清湾盐沼湿地有机碳密度及碳储量估算

Estimation of organic carbon density and carbon storage of salt marsh wetland in Yueqing bay

滨海盐沼湿地是蓝色碳汇的重要组成部分,充分挖掘盐沼湿地碳汇能力对我国应对气候变化具有重要的理论和现实意义。本研究在探明乐清湾盐沼植被分布的基础上,采用野外采样和实验室测定相结合的方式,研究了典型盐沼植被的固碳能力,定量估算乐清湾盐沼湿地的碳储量,并系统地分析了不确定性。结果表明:(1)乐清湾主要优势种为入侵种互花米草,分布面积为3352.87 ha,另有盐地碱蓬、芦苇等本地盐沼植物呈零星分布;(2)互花米草具有强大的固碳能力,其碳密度由地上生物量碳密度、地下生物量碳密度、沉积物碳密度构成,共计(102.97±9.52)Mg C/ha,其中沉积物碳密度的贡献最大,达(91.11±9.49)Mg C/ha;(3)乐清湾互花米草盐沼湿地总碳储量达(345244.99±31935.38)Mg C,不确定性为12.01%。其中,地上生物量碳储量为(16700.11±4814.43)Mg C,地下生物量碳储量为(23076.19±10005.75)Mg C,沉积物碳储量为(305468.70±31823.15)Mg C。研究结果可为海湾盐沼湿地保护提供科学依据,为建立完善的碳储量监测和评估体系提供参考。

The Coastal salt marsh wetland is an important type of coastal blue carbon ecosystems. Fully exploiting the potential carbon sink capacity of salt marsh wetland has essential importance in theoretical studies and practical management to cope with climate change. Based on the distribution of salt marsh vegetation in Yueqing bay, we studied the carbon storage of typical salt marsh vegetation by combining field sampling and laboratory measurements.The results showed that:(1) Spartina alterniflora was the main dominant species in Yueqing bay, and the area of 3352.87 ha. Meanwhile, Suaeda salsa and Phragmites australis were rarely observed in local salt marshes.(2) Spartina alterniflora has a strong carbon storage capacity. The carbon density of Spartina alterniflora was composed of aboveground biomass carbon density,belowground biomass carbon density, and sediment carbon density, with a total of(102.97 ± 9.52) Mg C/ha, of which the sediment carbon density had the maximal contribution, reaching(91.11 ± 9.49) Mg C/ha.(3) The total carbon storage of Yueqing bay was(345244.99 ± 31935.38) Mg C, with an uncertainty level of 12.01 %.Aboveground biomass carbon storage was(16700.11 ± 4814.43) Mg C;belowground biomass carbon storage was(23076.19 ± 10005.75) Mg C;sediment carbon storage was(305468.70 ± 31823.15) Mg C. This study can provide scientific basis for the protection of coastal salt marsh wetland and provide reference for establishing a perfect carbon storage monitoring and evaluation system.