 |
| Titel |
Mercury in coniferous and deciduous upland forests in northern New England, USA: implications of climate change |
| VerfasserIn |
J. B. Richardson, A. J. Friedland |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 12, no. 22 ; Nr. 12, no. 22 (2015-11-26), S.6737-6749 |
| Datensatznummer |
250118178
|
| Publikation (Nr.) |
 copernicus.org/bg-12-6737-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| Climatic changes in the northeastern US are expected to cause coniferous
stands to transition to deciduous stands over the next hundred years.
Mercury (Hg) sequestration in forest soils may change as a result. In order
to understand potential effects of such a transition, we studied aboveground
vegetation and soils at paired coniferous and deciduous stands on eight
mountains in Vermont and New Hampshire, USA. Organic horizons at coniferous
stands accumulated more total Hg (THg; 42 ± 6 g ha−1) than
deciduous stands (30 ± 4 g ha−1). Total Hg pools in the mineral
horizons were similar for coniferous (46 ± 8 g ha−1) and
deciduous stands (45 ± 7 g ha−1). Soil properties (C, % clay,
and pH) explained 56 % of the variation in mineral soil Hg concentration
when multiply regressed. Foliar and bole wood Hg concentrations were
generally greater for coniferous species than deciduous species. Using
allometric equations, we estimated that aboveground accumulation of Hg in
foliage and woody biomass was similar between vegetation types but that
coniferous stands have significantly smaller annual litterfall fluxes (0.03 g ha−1 yr−1)
than deciduous stands (0.24 g ha−1 yr−1).
We conclude that organic horizon Hg accumulation is influenced by vegetation
type but mineral horizon Hg accumulation is primarily controlled by soil
properties. Further investigations into the effect of vegetation type on
volatilization, atmospheric deposition, and leaching rates are needed to
constrain regional Hg cycling rates. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|