Litterfall mercury dry deposition in the eastern USA
Risch MR, DeWild JF, Krabbenhoft DP, Kolka RK, Zhang L. 2012. Litterfall mercury dry deposition in the eastern USA. Environmental Pollution. 161:284-290
Mercury (Hg) in autumnlitterfall frompredominately deciduous forestswas measured in 3 years of samples from 23 Mercury Deposition Network sites in 15 states across the eastern USA. Annual litterfall Hg dry depositionwas significantly higher (median 12.3 micrograms per square meter (mg/m2), range 3.5e23.4 mg/m2) than annual Hgwet deposition (median 9.6 mg/m2, range 4.4e19.7 mg/m2). The mean ratio of dry towet Hg deposition was 1.3e1. The sum of dry and wet Hg deposition averaged 21 mg/m2 per year and 55% was litterfall dry deposition. Methylmercury was a median 0.8% of Hg in litterfall and ranged from 0.6 to 1.5%. Annual litterfall Hg and wet Hg deposition rates differed significantly and wereweakly correlated. Litterfall Hg dry deposition differed among forest-cover types. This study demonstrated howannual litterfall Hg dry deposition rates approximate the lower bound of annual Hg dry fluxes.
- Type
- Journal Article
- Authors
- Risch, Martin; DeWild, John; Krabbenhoft, David; Kolka, Randall; Zhang, Leiming
- Units
- GRSM
- Keywords
- Dry Deposition, Elkmont, GRSM-00497, litterfall, Mercury, methylmercury, Wet Deposition
- Subjects
- Ecological Framework: Air and Climate | Air Quality | Wet and Dry Deposition