Road salt inputs alter biogeochemistry but not plant community composition in exurban forested wetlands

Forested wetlands of the temperate north are increasingly exposed to deicing salts, but it is unclear how this may alter wetland biogeochemistry and plant community composition. To investigate potential effects of deicing salts on exurban forested wetlands in southern New England, we employed a multi-site field study to describe spatiotemporal patterns of soil physiochemical, water quality, and vegetation characteristics with distance from road deicing salt source. We surveyed nine road-adjacent, red maple-dominated wetlands to quantify a suite of soil parameters (Na+, K+, Mg2+, Ca2+, pH, electrical conductivity (EC), heavy metals, N, P, soil moisture), as well as surface and groundwater salinity, and vegetation communities. With increasing distance from roads along 165-m transects penetrating into each wetland, soil salinity (EC, Na+) decreased, while soil base cation concentrations (Mg2+, Ca2+) increased, likely due to cation exchange (Na+ displacing other base cations). We also measu...