Watershed sulfur biogeochemistry: Shift from atmospheric deposition dominance to climatic regulation
Mitchell, MJ; Likens, GE
HERO ID
1673526
Reference Type
Journal Article
Year
2011
Language
English
PMID
| HERO ID | 1673526 |
|---|---|
| In Press | No |
| Year | 2011 |
| Title | Watershed sulfur biogeochemistry: Shift from atmospheric deposition dominance to climatic regulation |
| Authors | Mitchell, MJ; Likens, GE |
| Journal | Environmental Science & Technology |
| Volume | 45 |
| Issue | 12 |
| Page Numbers | 5267-5271 |
| Abstract | North American atmospheric S emissions peaked in the early 1970s followed by a dramatic decrease that resulted in marked declines in sulfate (SO₄²⁻)) concentrations in precipitation and many surface waters. These changes in S biogeochemistry have important implications with respect to the mobilization of toxic (Al(n⁺), H⁺) and nutrient (Ca²⁺, Mg²⁺, K⁺) cations and the acidification of watersheds. We used the continuous long-term record for watersheds 1, 3, 5, and 6 (37-44 years from 1965 through 2008) of SO₄²⁻ concentrations and fluxes at Hubbard Brook Experimental Forest in New Hampshire (U.S.) for evaluating S budgets. Analysis revealed that the annual discrepancies in the watershed S budgets (SO₄²⁻ flux in drainage waters minus total atmospheric S deposition) have become significantly (p < 0.001) more negative, indicating the increasing importance of the release of S from internal sources with time. Watershed wetness, as a function of log₁₀ annual water flux, was highly significant (p < 0.001) and explained 57% (n = 157) of the annual variation for the combined results from watersheds 1, 3, 5, and 6. The biogeochemical control of annual SO₄²⁻ export in streamwater of forested watersheds has shifted from atmospheric S deposition to climatic factors by affecting soil moisture. |
| Doi | 10.1021/es200844n |
| Pmid | 21595471 |
| Wosid | WOS:000291422200031 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Language Text | English |