Mercury cycling in litter and soil in different forest types in the Adirondack region, New York, USA.

The fate of mercury in decomposing leaf litter and soil is key to understanding the biogeochemistry of mercury in forested ecosystems. We quantified mercury dynamics in decomposing leaf litter and measured fluxes and pools of mercury in litterfall, throughfall, and soil in two forest types of the Adirondack region, New York, USA. The mean content of total mercury in leaf litter increased to 134% of its original mass during two years of decomposition. The accumulation pattern was seasonal, with significant increases in mercury mass during the growing season (+4.9% per month). Litterfall dominated mercury fluxes into the soil in the deciduous forest, whereas throughfall dominated fluxes into the coniferous forest. The increase in mercury mass in decomposing deciduous litter during the growing season was greater than could be accounted for by throughfall inputs during the growing season (P < 0.05), suggesting translocation of mercury from the soil to the decomposing deciduous litter. This internal recycling mechanism concentrates mercury in the organic horizons and retards transport through the soil, thereby increasing the residence time of mercury in the forest floor. A mass balance assessment suggests that the ultimate fate of mercury in the landscape depends upon forest type and associated differences in the delivery and incorporation of mercury into the soil. Our results show that incorporation of mercury into decaying leaf litter increases its residence time in the landscape and may further delay the recovery of surface waters, fish, and associated biota following control of mercury emissions to the atmosphere.

[1]  E. Matzner,et al.  Pools and fluxes of mercury and methylmercury in two forested catchments in Germany. , 2000, The Science of the total environment.

[2]  John Munthe,et al.  Atmospheric mercury—An overview , 1998 .

[3]  William F. Fitzgerald,et al.  The Case for Atmospheric Mercury Contamination in Remote Areas , 1998 .

[4]  G. E. Lang,et al.  A Critique of the Analytical Methods Used in Examining Decomposition Data Obtained From Litter Bags , 1982 .

[5]  J. Tjell,et al.  Plant uptake of airborne mercury in background areas , 1988 .

[6]  F. Morel,et al.  THE CHEMICAL CYCLE AND BIOACCUMULATION OF MERCURY , 1998 .

[7]  G. Aiken,et al.  Mercury(II) sorption to two Florida Everglades peats: evidence for strong and weak binding and competition by dissolved organic matter released from the peat. , 2000, Environmental science & technology.

[8]  A. Heyes,et al.  Methyl and total mercury in boreal wetland plants, experimental lakes area, northwestern Ontario , 1995 .

[9]  M. Meirvenne,et al.  Predictive Quality of Pedotransfer Functions for Estimating Bulk Density of Forest Soils , 2005 .

[10]  Lars Håkanson,et al.  Mercury in the Swedish environment — Recent research on causes, consequences and corrective methods , 1991 .

[11]  D. F. Grigal,et al.  Mercury budget of an upland-peatland watershed , 2000 .

[12]  G. Tyler.  Changes in the concentrations of major, minor and rare-earth elements during leaf senescence and decomposition in a Fagus sylvatica forest , 2005 .

[13]  R. Leonard.  Net precipitation in a northern hardwood forest , 1961 .

[14]  G. Likens,et al.  Nutrient Release From Decomposing Leaf and Branch Litter in the Hubbard Brook Forest, New Hampshire , 1973 .

[15]  R. Laskowski,et al.  The Dynamics of Chemical Elements in Forest Litter , 1995 .

[16]  John F. Muratore,et al.  Nitrogen and Lignin Control of Hardwood Leaf Litter Decomposition Dynamics , 1982 .

[17]  V. S. St. Louis,et al.  Methylmercury and total mercury in plant litter decomposing in upland forests and flooded landscapes. , 2004, Environmental science & technology.

[18]  J. Nriagu,et al.  The analysis of vegetation for total mercury , 1991 .

[19]  P. Bloom,et al.  Binding constants of divalent mercury (Hg2+) in soil humic acids and soil organic matter. , 2006, Environmental science & technology.

[20]  Å. Iverfeldt.  Mercury in forest canopy throughfall water and its relation to atmospheric deposition , 1991 .

[21]  S. Lindberg,et al.  Assessment of dry deposition and foliar leaching of mercury and selected trace elements based on washed foliar and surrogate surfaces , 2000 .

[22]  C. Monk,et al.  Patterns of basidiomycete nutrient accumulation in conifer and deciduous forest litter , 1975 .

[23]  J. Olson,et al.  Energy Storage and the Balance of Producers and Decomposers in Ecological Systems , 1963 .

[24]  D. Landers,et al.  Using lake sediment mercury flux ratios to evaluate the regional and continental dimensions of mercury deposition in arctic and boreal ecosystems , 1998 .

[25]  D. H. Knight,et al.  The nitrogen cycle in lodgepole pine forests, southeastern Wyoming , 1985 .

[26]  Charles T. Driscoll,et al.  Aluminium chemistry in a forested spodosol , 1985 .

[27]  J. Rudd,et al.  Importance of the forest canopy to fluxes of methyl mercury and total mercury to boreal ecosystems. , 2001, Environmental science & technology.

[28]  S. Lindberg,et al.  Dry deposition and foliar leaching of mercury and selected trace elements in deciduous forest throughfall , 2001 .

[29]  D. Engstrom,et al.  Recent Declines in Atmospheric Mercury Deposition in the Upper Midwest , 1997 .

[30]  S. E. Lindberg,et al.  Atmospheric Mercury Speciation: Concentrations and Behavior of Reactive Gaseous Mercury in Ambient Air , 1998 .

[31]  S. Lindberg,et al.  Mercury Accumulation in Foliage over Time in Two Northern Mixed-Hardwood Forests , 2002 .

[32]  E. Miller,et al.  Mercury Concentrations in Bicknell’s Thrush and Other Insectivorous Passerines in Montane Forests of Northeastern North America , 2005, Ecotoxicology.

[33]  N. Stark.  Nutrient Cycling Pathways and Litter Fungi , 1972 .

[34]  D. F. Grigal,et al.  Atmospheric Inputs of Mercury and Organic Carbon into a Forested Upland/Bog Watershed , 1999 .

[35]  Gene E. Likens,et al.  Throughfall and Stemflow Chemistry in a Northern Hardwood Forest , 1973 .

[36]  E. Dambrine,et al.  Xylem sap as a pathway for total mercury and methylmercury transport from soils to tree canopy in the boreal forest , 1998 .

[37]  D. E. Schorran,et al.  Accumulation of atmospheric mercury in forest foliage , 2003 .

[38]  Reed C. Harris,et al.  Reactivity and mobility of new and old mercury deposition in a boreal forest ecosystem during the first year of the METAALICUS study. Mercury Experiment To Assess Atmospheric Loading In Canada and the US. , 2002, Environmental science & technology.

[39]  L. Rustad.  Element Dynamics along a Decay Continuum in a Red Spruce Ecosystem in Maine, USA , 1994 .

[40]  E. Steinnes,et al.  Ectomycorrhizal heavy metal accumulation as a contributing factor to heavy metal levels in organic surface soils , 1995 .

[41]  William F. Fitzgerald,et al.  The biogeochemical cycling of elemental mercury: Anthropogenic influences☆ , 1994 .

[42]  B. Berg,et al.  Accumulation and release of plant nutrients in decomposing Scots pine needle litter. Long-term decomposition in a Scots pine forest II , 1982 .

[43]  Michael H. Kutner.  Applied Linear Statistical Models , 1974 .

[44]  O. Lindqvist,et al.  Cycling of mercury between water, air, and soil compartments of the environment , 1989 .

[45]  D. R. Jackson,et al.  Atmospheric Emission and Plant Uptake of Mercury from Agricultural Soils near the Almadén Mercury Mine , 1979 .

[46]  D. Engstrom,et al.  Historical and present fluxes of mercury to Vermont and New Hampshire lakes inferred from 210Pb dated sediment cores , 2002 .

[47]  Anthony Carpi,et al.  Application of a teflon™ dynamic flux chamber for quantifying soil mercury flux: Tests and results over background soil , 1998 .

[48]  C. Driscoll,et al.  Historical trends of mercury deposition in Adirondack lakes , 1999 .