滨海盐沼湿地因长期淹水而具有较高的生产量和较低的分解率, 储蓄了大量的土壤有机碳. 随着新恢复盐沼湿地发育年限的增加, 其植被生长特性、土壤理化性质与有机碳含量也发生了变化, 进而影响到固碳增汇功能. 本文以长江口横沙岛新恢复盐沼湿地为例, 利用时空代换法, 分析新恢复湿地不同发育年限与不同植被群落类型的植被生长性状及土壤有机碳变化情况, 并分析影响新恢复湿地固碳能力的关键因子. 结果表明: 新恢复盐沼湿地在0 ~ 20年内有机碳含量随发育年限的增长而增加, 且土壤孔隙度和含水率变化可有效指示土壤有机碳的变化; 新恢复湿地具有较高的土壤碳密度, 发育8年的湿地0 ~ 20 cm土层的总有机碳密度为(21.49 ± 3.67) tC·hm^–2, 接近自然湿地; 芦苇恢复湿地植被长势和固碳能力高于海三棱藨草和芦苇–海三棱藨草交错群落.

Coastal salt marsh wetlands have high productivity and low decomposition rates owing to long-term flooding, and these wetlands store a large amount of soil organic carbon. As newly restored salt marsh wetlands develop, changes in vegetation growth traits, soil physicochemical properties, and organic carbon content affect their carbon sequestration function. In this study, using a restored salt marsh wetland in Hengsha (Chongming, Shanghai) as an example, changes in the vegetation growth characteristics and soil organic carbon content of different vegetation communities at varying developmental ages were analyzed using the spatiotemporal substitution method. Key factors affecting the carbon sequestration capacity of these restored wetlands were also identified. The results showed that the organic carbon content in newly restored salt marsh wetlands increased with developmental age over 0 ~ 20 years. Soil porosity and water content were effective indicators of soil organic carbon content changes. The newly restored wetlands had a high soil carbon density, with a total organic carbon density of (21.49 ± 3.67) tC·hm^–2 in the 0 ~ 20 cm soil layer of the eight-year-old wetland, similar to that of the natural wetland. The vegetation growth and carbon sequestration capacity of Phragmites australis were higher than those of Scirpus mariqueter and their ecotone.