General Background:
• Salt marshes in the northeast characterized
by peat at the marsh surface overlying sands or gravels
• Early studies: Minimal groundwater nitrate processing in these sandy aquifers
• Recent studies:
Groundwater denitrification through these sands with high hydraulic conductivity
can
be
substantial
as
approach
coast
What has been our contribution?
Addy
et al. 2002
• New method to provide useful insights
into spatial and temporal patterns of groundwater denitrification in riparian
zones and at the coastal margin
Addy et al. 2005
• We found substantial groundwater denitrification
capacity in the low marsh year-round.
• Carbon additions did not alter groundwater denitrification
suggesting that an alternative electron donor may be limiting.
• Combining
flowpaths with denitrification capacity, we estimated that as
much as 29-60
mg N could be removed from 1 L of water flowing through the
groundwater below the low marsh, arguing for the significance of salt marshes
in annual watershed scale N budgets.
To learn more about our most recent work on groundwater denitrification in filled salt marshes, download this pdf of a powerpoint presentation.
