Abstract Mangroves fringe the coastlines of 54% of the world’s nations but convey ecosystem services, such as carbon sequestration, that span administrative boundaries. Despite their high carbon sequestration efficiency and long-term storage capacity, few countries have assembled detailed mangrove carbon inventories. For example, Brazil, which detains the second largest mangrove area in the world, still lacks a detailed inventory on its blue carbon resources, largely due to the scarcity of integrated ecosystem-level (that is, carbon stored in biomass and soil combined) carbon assessments. Here we combine published and unpublished data to derive an inventory on ecosystem-level carbon stocks and carbon sequestration rates in the Cananeia-Iguape lagoon estuarine system, southeastern Brazil. We find that mangroves in the study area have the largest per-unit-area ecosystem-level carbon stocks at 380 MgC ha−1 when compared to other Brazilian mangroves. Soil organic carbon stocks (top meter) account for 70% of this total. Annual carbon sequestration in mangrove soils and woody biomass combined with carbon fluxes via litterfall total 0.16 TgC yr−1. Degradation of mangrove ecosystems in this region could lead to CO2e emissions up to 1,395 MgCO2 ha−1 and reduce annual carbon sequestration in soil and biomass combined, and carbon flux via litterfall by 27 and 12 MgCO2 ha−1 yr−1, respectively. Our results provide coastal wetlands managers and scientists with novel information on mangrove carbon stocks and sequestration rates in the study area, which is useful to strengthen regional blue carbon and potential CO2e emission inventories. These estimates can also be used to establish performance measures to inform restoration targets as well as to serve as a baseline for comparison with current and future measurements of carbon stocks and fluxes in response to environmental change.

中文翻译：

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巴西东南部 Cananéia-Iguape 泻湖河口系统红树林的生态系统级碳储量和固存率

摘要 红树林位于世界 54% 国家的海岸线边缘，但提供跨越行政边界的生态系统服务，例如碳封存。尽管碳封存效率和长期储存能力高，但很少有国家收集了详细的红树林碳清单。例如，拥有世界第二大红树林区的巴西，其蓝碳资源仍然缺乏详细的清单，这主要是由于综合生态系统层面（即储存在生物量和土壤中的碳）碳的稀缺性。评估。在这里，我们结合已发表和未发表的数据，得出巴西东南部 Cananeia-Iguape 泻湖河口系统的生态系统级碳储量和碳固存率清单。我们发现，与其他巴西红树林相比，研究区的红树林具有最大的单位面积生态系统碳储量，为 380 MgC ha-1。土壤有机碳储量（最高米）占该总量的 70%。红树林土壤和木本生物量的年度固碳与通过凋落物产生的碳通量相结合，总计 0.16 TgC yr−1。该地区红树林生态系统的退化可能导致 CO2e 排放量高达 1,395 MgCO2 ha-1，并使土壤和生物量的年碳固存量以及通过凋落物产生的碳通量分别减少 27 和 12 MgCO2 ha-1 yr-1。我们的结果为沿海湿地管理者和科学家提供了有关研究区红树林碳储量和固存率的新信息，这有助于加强区域蓝碳和潜在的 CO2e 排放清单。