The effects of deicing salts on vegetation in Pinhook Bog, Indiana

Abstract

A 4-year study identified the effects of road salt contamination on the vegetation of Pinhook Bog after operation of an uncovered salt storage pile adjacent to the bog for 10 years. Nearly all of the endemic plant species (excluding moat species) were absent from the portion of the bog where mean salt concentrations as high as 468 mg/L sodium and 1215 mg/L chloride were measured in the interstitial waters of the peat mat. Skeletons of dead tamaracks remained. The impacted area was invaded by nonbog species and dominated by Typha angustifolia. As salt concentrations decreased by over 50% in 4 years, many of the endemic bog plants, including Sphagnum, returned to the impacted area. Declines were noted in the abundance of some of the invading species, while others continued expansion. Many of the invading and reestablished bog plants are known to be both salt tolerant and pioneers in secondary succession of disturbed bogs.