63 Mercury in the Environment: From Maine to Florida I

Tuesday, 16 March 2010
8:00 AM - 12:05 PM
Poe

MERCURY INPUTS, OUTPUTS, CYCLING, AND AMBIENT CONCENTRATIONS UNDER THE FOREST CANOPY IN THE ADIRONDACKS OF NEW YORK

Paper number: 63-3
Program: Theme Sessions
Time: 8:25 AM – 8:45 AM

Authors

Abstract

This study investigated mercury inputs, outputs, cycling, and the interactions between deposition, emissions and atmospheric conditions in the Huntington Forest of the Adirondacks, New York. The volume-weighted mean (VWM) total Hg concentration in throughfall (Dec. 2004 to Dec. 2006) (6.6 ng L-1) was higher than in precipitation (4.9 ng L-1), while the total cumulative Hg flux in throughfall (12.0 µg m-2) was similar to precipitation (11.6 µg m-2). The emission flux of GEM from the forest floor measured using a polycarbonate dynamic flux chamber (DFC) was highest in spring, and summer, and lowest in winter. The yearly estimated Hg inputs into the forest canopy include throughfall (6.5 mg m-2 year-1), litterfall (18.3 mg m-2 year-1), and dry deposition during leaf-off periods (0.4 mg m-2 year-1). The yearly estimated Hg outputs from the forest canopy include emission from the forest floor (6.3 mg m-2 year-1), soil water (0.6 mg m-2 year-1), and Hg loss via evaporation or overland flow during snow melt (1.0 mg m-2 year-1). Litterfall represented the most significant input of Hg to this forest ecosystem. Based on this mass balance, 17.3 mg m-2 of Hg is accumulating in the forest floor every year.