Date of Award

5-2002

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Science (MS)

Department

Ecology and Environmental Sciences

Advisor

J. Steve Kahl

Second Committee Member

Christopher S. Cronan

Third Committee Member

Ivan J. Fernandez

Abstract

Two small upland watersheds have been gauged and monitored at Acadia National Park since 1998. Cadillac Brook watershed burned in a wildfire in 1947. Hadlock Brook watershed has been undisturbed for several centuries, and serves as the reference site. Precipitation and throughfall volume and chemistry data have been collected using wetonly and continuously open collectors. Hydrologic and chemical inputs to the sites have been determined for each site. Differences in watershed and vegetation characteristics control the input of water and major ions to these watersheds. Vegetation type was the dominant control on enhancement of precipitation across the heterogeneous watersheds. Relative annual enhancement of throughfall over wet-only deposition for coniferous stands at Hadlock was 2.0 for NH4 and NO3, 2.7 for SO4, 7.1-7.3 for C1 and Na, 6.8 for Ca, 92 for Mg, and 58 for K. Enhancement was similar for mixed stands, intermediate for deciduous stands, and lowest (except C1 and Na) at scrub and open sites. At Cadillac, enhancement was slightly lower for each ion, but the same pattern, coniferous ≈ mixed > deciduous > scrublopen, was observed. Seasonal differences were important, with highest deposition in fall and summer; however, wet deposition inputs of C1 and Na were highest in winter. Elemental stream flux was calculated using discharge data from the U. S. Geological Survey, combined with periodic water chemistry data. The chemical mass balance in the watersheds was determined from streah outputs minus wet inputs, where negative values indicate retention within the watershed. At Cadillac and Hadlock, H, Mg, K, Na4, and NO3 are retained; Ca and SO4 are lost. Retention of DM (NO3 plus NH4) was 96% at Cadillac and 72% at Hadlock, indicating that differences related to vegetation and/or soils control the relative patterns of retention and release.

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