The responses of marsh elevation in four National Parks affected by Hurricane Sandy were examined using empirical data from surface elevation tables (SET) and modeling. The parks examined were Fire Island National Seashore and Gateway National Recreational Area in New York; Cape Cod National Seashore, Massachusetts; and Assateague Island National Seashore, Maryland. Observed vertical accretion rates were compared with calculations made with the Marsh Equilibrium Model (MEM). MEM predicts vertical accretion resulting from the accumulation of organic material in soil and the capture of suspended inorganic material at the marsh surface. MEM simulations of a decade or more of marsh elevation change at 52 SET stations were generally consistent with observations. Park-specific averages of observed vertical accretion ranged from 0.16 ± 0.33 (± 1 SD) to 0.51 ± 0.21 cm/year, while the range of calculated rates was 0.15 ± 0.03 to 0.22 ± 0.05 cm/year, depending on the park. Grand means of observed and calculated rates were 0.36 ± 0.34 and 0.19 ± 0.06 cm/year, respectively. We defined a novel metric termed normalized elevation capital (NEC) that incorporates information about tide range and elevation capital. All but 2.3% of biomass collections from all the parks fell within 0 < NEC < 1. Consistent with marsh equilibrium theory, long-term vertical accretion rate tended to be greatest, 0.4 ± 0.2 cm/year, in the range 0.4 < NEC < 0.6 where vertical accretion is dominated by organic production. Average episodic accretion during the storm from mineral deposition also was greatest and positive, 0.6 ± 0.9 cm in the range 0.4 < NEC < 0.6. Finally, one marsh in Gateway NRA, restored by an application of sediment to NEC = 0.55–0.68, had post-treatment vertical accretion rates of 0.36 ± 0.31 cm/year, not statistically different from SET stations elsewhere in Gateway, 0.57 ± 0.54 cm/year. The sediment amendment placed restored sites in the range of NEC where theory predicts that biogenic accretion should dominate vertical accretion. Model simulations suggest that current rates of vertical accretion in the parks are close to their theoretical limits, and in the absence of new sediment, extant marsh communities in these parks are unlikely to survive continued acceleration of sea-level rise in the absence of periodic sediment renourishment.

使用来自地面海拔表（SET）和模型的经验数据，考察了受飓风桑迪影响的四个国家公园中沼泽海拔的响应。检查的公园是纽约的火岛国家海滨和盖特威国家游乐区；马萨诸塞州科德角国家海滨；和马里兰州阿萨蒂格岛国家海岸。将观察到的垂直吸积率与使用Marsh平衡模型（MEM）进行的计算进行比较。MEM预测由于土壤中有机物质的积累和沼泽地表层悬浮无机物质的捕获而导致垂直堆积。在52个SET站进行十年或更长时间的沼泽海拔变化的MEM模拟与观察结果基本一致。观察到的垂直吸积的公园特定平均值范围为0.16±0.33（±1 SD）至0。51±0.21 cm /年，而计算速率的范围为0.15±0.03至0.22±0.05 cm /年，具体取决于公园。观测和计算速率的主要平均值分别为0.36±0.34和0.19±0.06 cm /年。我们定义了一种新的度量标准，称为归一化海拔资本（NEC），其中包含有关潮差和海拔资本的信息。从所有公园收集的生物量中，仅有2.3％落入0 <NEC <1范围内。根据沼泽平衡理论，长期垂直累积速率倾向于最大，在0.4 <0.2 cm /年，在0.4 <NEC < 0.6，垂直增长以有机生产为主。暴风雨期间矿物沉积的平均情节累积也最大且为正，在0.4 <NEC <0.6范围内为0.6±0.9 cm。最后，在Gateway NRA的一处沼泽，通过在NEC上施加沉积物恢复的碳含量为0.55-0.68，处理后的垂直吸积率为0.36±0.31 cm /年，与Gateway的SET站的0.57±0.54 cm /年无统计学差异。沉积物修正将恢复的地点置于NEC范围内，在该地点，理论预测生物成因应主导垂直成因。模型模拟表明，公园中当前的垂直增生速率已接近其理论极限，并且在没有新的沉积物的情况下，这些公园中现有的沼泽社区不可能在没有定期沉积物的情况下继续持续加速海平面上升养育。54厘米/年。沉积物修正将恢复的地点置于NEC范围内，在该地点，理论预测生物成因应主导垂直成因。模型模拟表明，公园中当前的垂直增生速率已接近其理论极限，并且在没有新的沉积物的情况下，这些公园中现有的沼泽社区不可能在没有定期沉积物的情况下继续持续加速海平面上升养育。54厘米/年。沉积物修正将恢复的地点置于NEC范围内，在该地点，理论预测生物成因应主导垂直成因。模型模拟表明，公园中当前的垂直增生速率已接近其理论极限，并且在没有新的沉积物的情况下，这些公园中现存的沼泽群落不可能在没有定期沉积物的情况下继续持续加速海平面上升养育。