HR: 0800h
AN: B11B-0154    [Abstracts]
TI: Landscape and Vegetative Influences on Mercury in Forest Litter at Acadia National Park
AU: * Sheehan, K D
EM: katherine.sheehan@umit.maine.edu
AF: Sen. George J. Mitchell Center, 102 Norman Smith Hall University of Maine, Orono, ME 04469-5710
AU: Fernandez, I J
EM: ivanjf@maine.edu
AF: University of Maine, Department of Plant, Soil & Environmental Sciences 1 Deering Hall University of Maine, Orono, ME 04469
AU: Kahl, J S
EM: jskahl@plymouth.edu
AF: Center for the Environment, MSC #63 213 Boyd Hall Plymouth State University , Plymouth, NH 03264
AU: Amirbahman, A
EM: aria@umit.maine.edu
AF: University of Maine, Department of Civil and Evironmental Engineering 5711 Boardman Hall University of Maine, Orono, ME 04469
AB: Litterfall, or leaves and other matter that falls from the forest canopy to the forest floor, is a predominant vector of mercury (Hg) deposition to forested watersheds. Leaves, the primary component of litterfall, primarily accumulate atmospheric Hg by diffusive vapor exchange through stomata. Vegetative and non-vegetative factors dictate Hg accumulation in foliage. This research examines the influence that factors such as vegetation type, aspect, elevation and canopy coverage have on the concentration of total-Hg in litterfall in two study watersheds in Acadia National Park (ANP), Maine, U.S.A. Litterfall was measured at 39 sites, spanning 14 months, in paired gauged watersheds with ongoing Hg monitoring. Initial results suggest that the annual flux of Hg in litterfall exceeds the magnitude of other input vectors of wet or dry deposited Hg by a factor of two. Vegetation type influenced mass of litter (mean \pm SD), which was greater at deciduous sites (12.2 g/mo \pm 10.8) than at coniferous sites (5.7 g/mo \pm 3.8). The annual flux of Hg in litterfall will be quantified and compared to Hg in wet-only precipitation and throughfall. Litterfall Hg flux will be compared for each landscape and vegetation factor to test the hypothesis that the quantity of litterfall ultimately controls the flux of litterfall Hg.
DE: 1065 Trace elements (3670)
DE: 0315 Biosphere/atmosphere interactions
DE: 0330 Geochemical cycles
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting