We assessed the influence of the intertidal and salinity gradients and mangrove forest structure on C stocks and sequestration rates in mangrove soils of an estuarine system in Todos os Santos Bay, Eastern Brazil. The accumulation rates of organic C (C_org) during the last century varied between and within estuarine zones, ranging from 65 to 1073 g C_org m⁻² yr⁻¹. The mean stocks of C_org and N for the top 1 m soils were 263 ± 14 Mg C_org ha⁻¹ and 11.8 ± 0.4 Mg N ha⁻¹, respectively. We found a less variable distribution pattern on C_org and N stocks throughout the salinity gradient than along the intertidal gradient, being significantly higher at the fringe mangroves than at the interior forest. We estimated that Brazil, one of the major reservoirs of mangroves (~ 10%) on the planet, has 207 ± 34 Tg C_org in the upper meter of soils, which represents 3–8% of the C stored in mangrove soils globally. Given that Brazil is a Blue Carbon hotspot, it is emphasized the urgent need for the establishment of better mangrove conservation practices and a comprehensive evaluation of their value in climate change mitigation and adaptation strategies for reducing CO₂ emissions.

中文翻译：

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巴西红树林中的蓝碳储量，累积率和相关的空间变异性

我们评估了潮间带和盐度梯度以及红树林结构对巴西东部Todos os Santos湾河口系统红树林土壤中碳库和固存速率的影响。在上个世纪之间，河口区域之间和之内的有机碳（C _org）的累积速率在65至1073 g C _org m ^-2 yr ^{-1之间变化}。前1 m的土壤中C _org和N的平均储量分别为263±14 Mg C _org ha ^-1和11.8±0.4 Mg N ha ^-1。我们发现C _org上的变量分布模式较少在整个盐度梯度上，N种群比在潮间梯度上高；在边缘红树林中，N种群明显高于内部森林。我们估计，巴西是地球上主要的红树林储层之一（约占10％），在较高的土壤表层土壤中具有207±34 Tg C _org，这代表了全球红树林土壤中C的3–8％。鉴于巴西是“蓝碳”的热点地区，因此强调迫切需要建立更好的红树林保护措施，并对其在减少气候变化和减少CO ₂排放的适应战略中的价值进行全面评估。