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Soil mercury and its response to atmospheric mercury deposition across the northeastern United States
Author(s) -
Yu Xue,
Driscoll Charles T.,
Warby Richard A. F.,
Montesdeoca Mario,
Johnson Chris E.
Publication year - 2014
Publication title -
ecological applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.864
H-Index - 213
eISSN - 1939-5582
pISSN - 1051-0761
DOI - 10.1890/13-0212.1
Subject(s) - mercury (programming language) , environmental chemistry , soil water , deposition (geology) , terrestrial ecosystem , soil carbon , environmental science , ecosystem , sink (geography) , mercure , soil organic matter , organic matter , soil horizon , chemistry , soil science , ecology , geology , sediment , geography , analytical chemistry (journal) , paleontology , cartography , organic chemistry , computer science , biology , programming language
Terrestrial soil is a large reservoir of atmospherically deposited mercury (Hg). However, few studies have evaluated the accumulation of Hg in terrestrial ecosystems in the northeastern United States, a region which is sensitive to atmospheric Hg deposition. We characterized Hg and organic matter in soil profiles from 139 sampling sites for five subregions across the northeastern United States and estimated atmospheric Hg deposition to these sites by combining numerical modeling with experimental data from the literature. We did not observe any significant relationships between current net atmospheric Hg deposition and soil Hg concentrations or pools, even though soils are a net sink for Hg inputs. Soil Hg appears to be preserved relative to organic carbon (OC) and/or nitrogen (N) in the soil matrix, as a significant negative relationship was observed between the ratios of Hg/OC and OC/N ( r = 0.54, P < 0.0001) that shapes the horizonal distribution patterns. We estimated that atmospheric Hg deposition since 1850 (3.97 mg/m 2 ) accounts for 102% of the Hg pool in the organic horizons (3.88 mg/m 2 ) and 19% of the total soil Hg pool (21.32 mg/m 2 ), except for the southern New England (SNE) subregion. The mean residence time for soil Hg was estimated to be 1800 years, except SNE which was 800 years. These patterns suggest that in addition to atmospheric deposition, the accumulation of soil Hg is linked to the mineral diagenetic and soil development processes in the region.