The evolution of the science of Bear Brook Watershed in Maine, USA
Norton, SA; Fernandez, IJ; Kahl, JS; Rustad, LE; Navrátil, T; Almquist, H
HERO ID
2023686
Reference Type
Journal Article
Year
2010
Language
English
PMID
| HERO ID | 2023686 |
|---|---|
| In Press | No |
| Year | 2010 |
| Title | The evolution of the science of Bear Brook Watershed in Maine, USA |
| Authors | Norton, SA; Fernandez, IJ; Kahl, JS; Rustad, LE; Navrátil, T; Almquist, H |
| Journal | Environmental Monitoring and Assessment |
| Volume | 171 |
| Issue | 3-21 |
| Page Numbers | 3-21 |
| Abstract | The Bear Brook Watershed in Maine (BBWM), USA is a paired watershed study with chemical manipulation of one watershed (West Bear = WB) while the other watershed (East Bear = EB) serves as a reference. Characterization of hydrology and chemical fluxes occurred in 1987-1989 and demonstrated the similarity of the ca. 10 ha adjacent forested watersheds. From 1989-2010, we have added 1,800 eq (NH(4))(2)SO(4) ha(-1) y(-1) to WB. EB runoff has slowly acidified even as atmospheric deposition of SO4(-2) has declined. EB acidification included decreasing pH, base cation concentrations, and alkalinity, and increasing inorganic Al concentration, as SO4(-2) declined. Organic Al increased. WB has acidified more rapidly, including a 6-year period of increasing leaching of base cations, followed by a long-term decline of base cations, although still elevated over pretreatment values, as base saturation declined in the soils. Sulfate in WB has not increased to a new steady state because of increased anion adsorption accompanying soil acidification. Dissolved Al has increased dramatically in WB; increased export of particulate Al and P has accompanied the acidification in both watersheds, WB more than EB. Nitrogen retention in EB increased after 3 years of study, as did many watersheds in the northeastern USA. Nitrogen retention in WB still remains at over 80%, in spite of 20+ years of N addition. The 20-year chemical treatment with continuous measurements of critical variables in both watersheds has enabled the identification of decadal-scale processes, including ecosystem response to declining SO4(-2) in ambient precipitation in EB and evolving mechanisms of treatment response in WB. The study has demonstrated soil mechanisms buffering pH, declines in soil base saturation, altered P biogeochemistry, unexpected mechanisms of storage of S, and continuous high retention of treatment N. |
| Doi | 10.1007/s10661-010-1528-y |
| Pmid | 20556651 |
| Wosid | WOS:000283592800002 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Language Text | English |
| Keyword | Bear Brook Watershed in Maine; Acidification; Streams; Soil; Nitrogen; Sulfur; Phosphorus; Base cations |