School of Environmental Science and Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou, 310018, China; Key Laboratory for Technology in Rural Water Management of Zhejiang Province, Hangzhou, 310018, China.
School of Hydraulic Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou, 310018, China; Key Laboratory for Technology in Rural Water Management of Zhejiang Province, Hangzhou, 310018, China.
J Environ Manage. 2024 Oct;369:122283. doi: 10.1016/j.jenvman.2024.122283. Epub 2024 Aug 28.
Salt marshes cover the largest area among the three types of traditional blue carbon ecosystems in China's coastal zone, with the introduced smooth cordgrass (Spartina alterniflora Loisel.) being dominant in these marshes. The effects of eradicating S. alterniflora nationwide and the subsequent ecological restoration on blue carbon are unclear. This paper evaluates the variation in blue carbon during the national S. alterniflora eradication campaign, which involves mechanical tillage from 2022 to 2025, and proposes three scenarios for blue carbon changes after native vegetation is reestablished by 2050. The results show that, in 2025, plant carbon stock and soil carbon stock will decrease by 1.38 Tg C and 1.21 Tg C, respectively, in the areas where S. alterniflora has been removed and managed. Although blue carbon is reduced in coastal wetlands in 2025, carbon stock is expected to increase in restored native vegetated wetlands by 2050. S. alterniflora is resilient and competitive, posing a high risk in secondary invasion. Scenario Ⅰ suggests that S. alterniflora marshes could almost recover to their original state from 2022, with 7.70 Tg C stored in plant and soil carbon stocks. Scenario Ⅱ involves native vegetated wetlands coexisting with invasive S. alterniflora marshlands, with a total carbon stock estimated at 7.15 Tg C, reflecting a decrease of 0.39 Tg C in soil carbon stock and by 0.16 Tg C in plant carbon stock. In Scenario Ⅲ, mudflats dominant and native vegetated habitats are reestablished only in suitable sites, with the total carbon stock estimated at 5.63 Tg C, a 26.9% decrease compared to 2022 levels. While eradicating invasive S. alterniflora and restoring native vegetation in China's coast enhance the ecosystem services, it reduces blue carbon stocks. Therefore, developing additional strategies to increase carbon storage in coastal wetlands is necessary.
盐沼是中国沿海三种传统蓝碳生态系统中面积最大的一种，其中互花米草（ Spartina alterniflora Loisel. ）占主导地位。全国范围内根除互花米草及其随后对蓝碳的生态恢复的影响尚不清楚。本文评估了 2022 年至 2025 年期间全国范围内根除互花米草的行动对蓝碳的影响，并提出了 2050 年之前恢复本地植被后蓝碳变化的三种情景。结果表明，到 2025 年，在已去除和管理的互花米草区域，植物碳储量和土壤碳储量将分别减少 1.38 TgC 和 1.21TgC。虽然 2025 年沿海湿地的蓝碳减少了，但到 2050 年，恢复的本地植被湿地的碳储量预计会增加。互花米草具有弹性和竞争力，存在二次入侵的高风险。情景Ⅰ表明，从 2022 年开始，互花米草沼泽地可能几乎可以恢复到原来的状态，植物和土壤碳储量分别为 7.70TgC。情景Ⅱ涉及本地植被湿地与入侵互花米草沼泽地共存，总碳储量估计为 7.15TgC，土壤碳储量减少 0.39TgC，植物碳储量减少 0.16TgC。情景Ⅲ中，仅在适宜的地点重新建立了泥滩主导和本地植被生境，总碳储量估计为 5.63TgC，与 2022 年相比下降了 26.9%。虽然中国沿海地区根除入侵的互花米草和恢复本地植被增强了生态系统服务功能，但它减少了蓝碳储量。因此，有必要制定其他增加沿海湿地碳储存的策略。
