Potential Nitrogen Removal by Restoring Wetlands on Retired Cranberry Bogs

What are the water quality benefits of wetland restoration?

We answered this question using field measurements of nitrogen fluxes in groundwater and surface water at Tidmarsh. We found that Tidmarsh retained 28% of the nitrogen entering as surface water and groundwater. Although 28% nitrogen retention was low compared with natural wetlands, it will likely improve as vegetation and soils mature, which may increase residence times, enhance hydrologic connectivity, and facilitate favorable conditions for biogeochemical transformations the promote nitrogen retention.

Seasonality of NO3- retention (Fret) for Tidmarsh between Jan. 2020 and Jan. 2021 (N = 7-11 per season). Seasons correspond to the following dates: spring (1 Apr. to 30 Jun.), summer (1 Jul. to 30 Sep.), autumn (1 Oct. to 31 Dec.), winter (1 Jan. to 31 Mar.) Bars not connected by the same letter are significantly different at 95% confidence (two-tailed t test; p value ≤ 0.05).


By Casey Kennedy
August 20, 2022