Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
Shanghai Institute of Pollution Control and Ecological Security, Shanghai, China.
Environ Monit Assess. 2020 Aug 18;192(9):585. doi: 10.1007/s10661-020-08547-0.
Wetlands are carbon pools for terrestrial ecosystems and play an important role in the global carbon cycle. The Nanhui tidal flat is located at the Yangtze River estuary and has been disturbed by various human activities. However, the effect of human activities on the carbon accumulation capability and carbon storage of wetlands in the Nanhui tidal flat is poorly understood. In this study, the annual carbon accumulation capability and carbon storage of three types of Spartina alterniflora Loisel. wetlands in the Nanhui tidal flat, which were defined as a natural wetland, silt-promoting wetland, and artificial restored wetland, were evaluated by analyzing the plant carbon fixation capability, soil carbon emissions, and soil organic carbon (SOC) density. The results showed that the three wetlands all had a carbon sink effect and the natural wetland, artificial restored wetland, and silt-promoting wetland annually accumulated 7.94, 7.14, and 6.33 kg m CO, respectively. The existing SOC density in the subsurface soil (0-40 cm) in the natural wetland, silt-promoting wetland, and artificial restored wetland was 23.26, 17.95, and 12.21 kg m CO2, respectively. The natural wetland, with no human disturbance, had a longer duration of waterlogging and greater tidal nutrition inputs than the other wetlands, resulting in a higher plant biomass and lower soil respiration (SR). It therefore had the strongest carbon accumulation capability and highest SOC storage.
湿地是陆地生态系统的碳汇，在全球碳循环中发挥着重要作用。南汇滩涂位于长江口，受到各种人类活动的干扰。然而，人类活动对南汇滩涂湿地的碳积累能力和碳储量的影响还知之甚少。本研究通过分析植物碳固定能力、土壤碳排放和土壤有机碳（SOC）密度，评估了南汇滩涂三种不同类型的互花米草湿地（自然湿地、促淤湿地和人工修复湿地）的年碳积累能力和碳储量。结果表明，三种湿地均具有碳汇效应，自然湿地、人工修复湿地和促淤湿地的年碳积累分别为 7.94、7.14 和 6.33kg m-2CO2。在自然湿地、促淤湿地和人工修复湿地的表层土壤（0-40cm）中，现有的 SOC 密度分别为 23.26、17.95 和 12.21kg m-2CO2。自然湿地由于没有人为干扰，积水时间更长，潮汐养分输入更多，导致植物生物量更高，土壤呼吸（SR）更低，因此具有最强的碳积累能力和最高的 SOC 储量。
