Details

Autor(en) / Beteiligte

• Fatemi, Farrah R.
• Fernandez, Ivan J.
• Szillery, Johanna
• Norton, Stephen A.
• Rustad, Lindsey E.

Titel

Soil Solution Chemical Response to Two Decades of Experimental Acidification at the Bear Brook Watershed in Maine

Ist Teil von

• Water, air, and soil pollution, 2012-11, Vol.223 (9), p.6171-6186

Ort / Verlag

Dordrecht: Springer Netherlands

Erscheinungsjahr

2012

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We examined long-term changes in soil solution chemistry associated with experimental, whole watershed-acidification at the Bear Brook Watershed in Maine (BBWM). At BBWM, the West Bear (WB) watershed has been treated with bimonthly additions of ((NH 4 ) 2 SO 4 ) since 1989. The adjacent East Bear (EB) watershed serves as a biogeochemical reference. Soil solution chemistry in the EB watershed was relatively stable from 1989–2007, with the exception of declining SO 4 –S concentrations associated with a progressive decline in SO 4 –S deposition during this period. Soil solution chemistry in WB reflected a progressive change in acid-neutralization mechanisms from base cation buffering to Al buffering associated with treatment during this period. Total dissolved Al concentrations progressively increased over time and were ~4× higher in 2007 than in 1989. Treatment of WB was also associated with long-term increases in soil solution H + , SO 4 –S, and NO 3 –N, whereas soil solution dissolved organic carbon (DOC) was unresponsive to treatment. For solutes such as Ca, H + , and SO 4 –S, changes in stream chemistry were generally parallel to changes in soil solution chemistry, indicating a close coupling of terrestrial and aquatic processes that regulate the chemistry of solutions in this first-order stream watershed. For other solutes such as Al and DOC, solute concentrations were higher in soil solutions compared with streams, suggesting that sorption and transformation processes along hydrologic flow-paths were important in regulating the chemistry of solutions and the transport of these solutes.