Restorations of former cranberry farms (“bogs”) aim to re-establish native wetland vegetation, promote cold water habitat, and attenuate nitrogen (N) delivery to coastal waters. It is unclear, though, how elements of restoration design such as microtopography, groundwater interception, and plant communities affect N removal via denitrification. In a recently restored riparian cranberry bog with created microtopography, we compared denitrification potential, nitrous oxide (N₂O) yield of denitrification (ratio of N₂O:N₂O + N₂ gases), in situ N₂O fluxes, soil chemistry, and plant communities at the highest and lowest elevations within 20 plots and at four side-channel groundwater seeps. Denitrification potential was > 2 × greater at low elevations, which had plant communities distinct from high elevations, and was positively correlated with plant species richness (Spearman’s rho = 0.43). Despite detecting high N₂O yield (0.86 ± 0.16) from low elevation soils, we observed small N₂O emissions in situ, suggesting minimal incomplete denitrification even in saturated depressions. Groundwater seeps had an order of magnitude higher denitrification potentials and 100–300 × greater soil NO₃− concentrations than the typically saturated low elevation soils. Groundwater seeps also had high N₂O yield (1.05 ± 0.15) and higher, but spatially variable, in situ N₂O emissions. Our results indicate that N removal is concentrated where soils interact with NO₃–rich groundwater, but other factors such as low soil carbon (C) also limit denitrification. Designing restoration features to increase groundwater residence time, particularly in low lying, species rich areas, may promote more N attenuation in restored cranberry bogs and other herbaceous riparian wetlands.

恢复前蔓越莓农场（“沼泽”）的目的是重建原生湿地植被，促进冷水栖息地，并减少向沿海水域的氮（N）输送。然而，目前尚不清楚恢复设计的要素（例如微地形、地下水拦截和植物群落）如何影响反硝化过程中的氮去除。在最近恢复的具有微地形的河岸蔓越莓沼泽中，我们比较了反硝化潜力、反硝化一氧化二氮 (N ₂ O) 产量（N ₂ O:N ₂ 气体）、原位 N ₂ O 通量、土壤化学以及 20 个地块内和四个侧河道最高和最低海拔处的植物群落地下水渗漏。低海拔地区的反硝化潜力大于 2 倍，其植物群落与高海拔地区不同，并且与植物物种丰富度呈正相关（Spearman’s rho = 0.43）。尽管从低海拔土壤中检测到高 N ₂ O 产量 (0.86 ± 0.16)，但我们在原位观察到少量 N ₂ O 排放，这表明即使在饱和洼地中，不完全反硝化作用也极小。与典型的饱和低海拔土壤相比，地下水渗漏的反硝化潜力高出一个数量级，土壤 NO ₃ - 浓度高出 100-300 倍。地下水渗漏也具有较高的 N ₂ O 产量 (1.05 ± 0.15) 和较高但空间可变的原位 N ₂ O 排放。我们的结果表明，氮去除集中在土壤与富含 NO ₃ 的地下水相互作用的地方，但低土壤碳 (C) 等其他因素也限制了反硝化。 设计恢复特征以增加地下水停留时间，特别是在低洼、物种丰富的地区，可能会促进恢复的蔓越莓沼泽和其他草本河岸湿地的氮素进一步衰减。