Manganese biogeochemistry in a small Adirondack forested lake watershed

Water Resources Research



In September and October 1981, manganese (Mn) concentrations and pH were intensively monitored in a small forested lake watershed in the west-central Adirondack Mountains, New York, during two large acidic storms (each ∼5 cm rainfall, pH 4.61 and 4.15). The data were evaluated to identify biogeochemical pathways of Mn and to assess how these pathways are altered by acidic atmospheric inputs. Concentrations of Mn averaged 1.1 μg/L in precipitation and increased to 107 μg/L in canopy throughfall, the enrichment reflecting active biological cycling of Mn. Rain pH and throughfall Mn were negatively correlated, suggesting that foliar leaching of Mn was enhanced by rainfall acidity. The pulselike input of Mn to the forest floor in the high initial concentrations in throughfall (∼1000 μg/L) did not affect Mn concentrations in soil water (< 20 μg/L) or groundwater (usually < 40 μg/L), which varied little with time. In the inlet stream, Mn concentrations remained constant at 48 μg/L as discharge varied from 1.1 to 96 L/s. Manganese was retained in the vegetative cycle and regulated in the stream by adsorption in the soil organic horizon. The higher Mn levels in the stream may be linked to its high acidity (pH 4.2–4.3). Mixing of Mn-rich stream water with neutral lake water (pH 7.0) caused precipitation of Mn and deposition in lake sediment.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Manganese biogeochemistry in a small Adirondack forested lake watershed
Series title Water Resources Research
DOI 10.1029/WR022i012p01647
Volume 22
Issue 12
Year Published 1986
Language English
Publisher American Geophysical Union
Description 10 p.
First page 1647
Last page 1656
Country United States
State New York
Other Geospatial Adirondack Mountains
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