Dataset: Temporal variability of carbon and nutrient burial, sediment accretion, and mass accumulation over the past century in a carbonate platform mangrove forest of the Florida Everglades

The objective of this research was to measure temporal variability in accretion and mass sedimentation rates (including organic carbon (OC), total nitrogen (TN), and total phosphorous (TP)) from the past century in a mangrove forest on the Shark River in Everglades National Park, USA. The 210Pb Constant Rate of Supply model was applied to six soil cores to calculate annual rates over the most recent 10, 50, and 100 year time spans. Our results show that rates integrated over longer timeframes are lower than those for shorter, recent periods of observation. Additionally, the substantial spatial variability between cores over the 10 year period is diminished over the 100 year record, raising two important implications. First, a multiple-decade assessment of soil accretion and OC burial provides a more conservative estimate and is likely to be most relevant for forecasting these rates relative to long-term processes of sea level rise and climate change mitigation. Second, a small number of sampling locations are better able to account for spatial variability over the longer periods than for the shorter periods. The site average 100 year OC burial rate, 123 +/- 19 (standard deviation) g m-2 yr-1, is low compared with global mangrove values. High TN and TP burial rates in recent decades may lead to increased soil carbon remineralization, contributing to the low carbon burial rates. Finally, the strong correlation between OC burial and accretion across this site signals the substantial contribution of OC to soil building in addition to the ecosystem service of CO2 sequestration.本研究旨在量化美国大沼泽地国家公园鲨鱼河红树林湿地近一个世纪以来的沉积物加积速率与质量沉积速率（包括有机碳（organic carbon, OC）、总氮（total nitrogen, TN）与总磷（total phosphorous, TP））的时间变异性。本研究对6个土壤岩芯应用210Pb恒定补给速率模型（Constant Rate of Supply Model, CRS），计算了近10年、50年及100年三个时间跨度下的年际速率。 研究结果显示，较长时间尺度下整合得到的速率低于近期较短观测时段的速率。此外，10年尺度下岩芯间存在显著的空间异质性，而在100年的记录中该空间异质性会被显著削弱，由此引出两项重要启示：其一，针对土壤加积与有机碳埋藏的数十年尺度评估，所得估算结果更为保守，且相较于海平面上升与气候变化缓解的长期过程，该尺度的评估结果与这些速率的预测关联更为紧密；其二，相较于较短时间尺度，少量采样点位即可更好地覆盖较长时间尺度下的空间异质性。 该位点100年尺度的有机碳埋藏平均速率为123 ± 19（标准差）g·m⁻²·yr⁻¹，低于全球红树林的平均水平。近数十年间较高的总氮与总磷埋藏速率，可能会加剧土壤碳的矿化作用，进而导致较低的碳埋藏效率。最后，该位点有机碳埋藏与沉积加积之间存在强相关性，这表明除二氧化碳封存这一生态系统服务功能外，有机碳还对土壤构建过程有着重要贡献。