Role of within-lake processes and hydrobiogeochemical changes over 16 years in a watershed in the Adirondack Mountains of New York State, USA
نویسندگان
چکیده
Hydrological and biogeochemical relationships were evaluated for the Arbutus Watershed in the Adirondack Mountains of New York State. Wet-only precipitation inputs (weekly) and discharge losses were evaluated from 1983 to 1998. Precipitation from 1983–98 had significant p < 0Ð05 decreases in concentrations of Ca2C 0Ð10 μmolc l 1 year 1 , Mg2C 0Ð07 μmolc l 1 year 1 , KC 0Ð01 μmolc l 1 year 1 , NaC 0Ð04 μmolc l 1 year 1 , Cl 0Ð07 μmolc l 1 year 1 , SO4 0Ð82 μmolc l 1 year 1 and HC 0Ð55 μmolc l 1 year 1 , whereas NH4C and NO3 concentrations did not change. For the same period, there were decreases in solute concentrations in the Arbutus Lake outlet for Ca2C 1Ð18 μmolc l 1 year 1 , Mg2C 0Ð32 μmolc l 1 year 1 , KC 0Ð33 μmolc l 1 year 1 , Cl 0Ð17 μmolc l 1 year 1 and SO4 1Ð90 μmolc l 1 year 1 and a significant increase in NH4C concentrations C0Ð07 μmolc l 1 year 1 . For the period from 1995 through 1998 the discharge measurements for the outlet and the major inlet of Arbutus Lake were combined with weekly chemical measurements supplemented with storm sampling. At the inlet there were significant relationships p < 0Ð05 between discharge rates and the concentrations of all solutes except Cl , but only for NaC, NO3 , HC and Al did these relationships explain more than 20% of the variation in solute concentrations. April had the greatest rates of discharge and solute flux of any month due to spring snowmelt. The dormant season (October–May) accounted for >80% of the discharge in the inlet and outlet of Arbutus Lake and >78% of the flux of all solutes. For 1995–98 the mass balances of discharge losses from the catchment draining into Arbutus Lake inlet versus precipitation inputs suggest that internal watershed processes resulted in net generation of Ca2C 1342 molc ha 1 year 1 , Mg2C 313 molc ha 1 year 1 , KC 35 molc ha 1 year 1 , SO4 635 molc ha 1 year 1 and Cl 45 molc ha 1 year 1 and net retention of inorganic N solutes (NO3 C NH4C: 204 molc ha 1 year 1) and HC 424 molc ha 1 year 1 . Concentrations and fluxes of Ca2C, HC, NO3 , SO4 and Al were lower at the lake outlet compared with the inlet. A comparison of mass balances at the Arbutus Lake inlet and outlet suggested that these decreases may have been due to within-lake biotic processes and/or dilution from other water sources to the lake. Copyright 2001 John Wiley & Sons, Ltd.
منابع مشابه
Impacts of changing climate and atmospheric deposition on N and S drainage losses from a forested watershed of the Adirondack Mountains, New York State
Biogeochemical responses to changing climate and atmospheric deposition were investigated using nitrogen (N) and sulfur (S) mass balances, including dry deposition and organic solutes in the Arbutus Lake watershed in the Adirondack Mountains, New York State. Long-term monitoring of wet-only precipitation (NADP/NTN, 1983–2001) and dry deposition (AIRMoN, 1990–2001) at sites adjacent to the water...
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