Mangroves are among the most carbon-rich terrestrial ecosystems, primarily attributable to the soil pool. There are substantial differences in soil carbon (C) and nitrogen (N) due to the disparities in geomorphic settings and ecological drivers, but this insight is drawn primarily from observational studies. An objective inventory of carbon stocks in mangroves of the Rufiji River Delta, Tanzania was conducted. Seventy-five soil cores were collected within a 12,164 ha inventory area, comprising the northern portion of the delta. Cores were collected from intact and dwarf mangroves, agricultural fields, and mudflats. The spatial mean soil organic carbon (SOC) density in mangroves was 16.35 ± 6.25 mg C cm⁻³. Mean SOC density in non-vegetated mudflats was 12.16 ± 4.57 mg C cm⁻³, demonstrating that mangroves develop on soils with a substantial soil C stock. However, long-established mangroves had had a higher C density (17.27 ± 5.87 mg C cm⁻³). Using a δ¹³C mixing model, the source of soil organic matter in mudflats was primarily marine, while long-established mangroves was predominantly mangrove. There were small differences in SOC among long-established mangrove sites in different geomorphic settings. The proportion of marine-sourced SOC increased with soil depth in mangroves. The SOC and nitrogen of agricultural sites resemble those of mudflats, suggesting those sites are developed from relatively young forests. The SOC and nitrogen density in dwarf mangrove sites were lower than others, perhaps reflecting past disturbances.

红树林是碳含量最高的陆地生态系统之一，主要归因于土壤池。由于地貌环境和生态驱动因素的差异，土壤碳 (C) 和氮 (N) 存在显着差异，但这种见解主要来自观察性研究。对坦桑尼亚鲁菲吉河三角洲红树林的碳储量进行了客观清查。在包括三角洲北部的 12,164 公顷库存区域内收集了 75 个土壤芯。从完整和矮小的红树林、农田和泥滩收集岩心。红树林的空间平均土壤有机碳 (SOC) 密度为 16.35 ± 6.25 mg C cm ^-3。非植被泥滩的平均 SOC 密度为 12.16 ± 4.57 mg C cm ^-3，表明红树林在具有大量土壤碳储量的土壤上发育。然而，历史悠久的红树林具有较高的 C 密度（17.27 ± 5.87 mg C cm ^-3）。使用δ ¹³ C混合模型，泥滩土壤有机质的来源主要是海洋，而历史悠久的红树林主要是红树林。在不同地貌环境中，历史悠久的红树林地点之间的 SOC 差异很小。红树林中海洋源有机碳的比例随着土壤深度的增加而增加。农业场地的 SOC 和氮与泥滩相似，表明这些场地是从相对年轻的森林发展而来的。矮化红树林地点的 SOC 和氮密度低于其他地点，这可能反映了过去的干扰。