Controls on surface water chemistry in two lake‐watersheds in the Adirondack region of New York: differences in nitrogen solute sources and sinks

摘要: The southwestern Adirondack region of New York receives among the highest rates atmospheric nitrogen (N) deposition in USA. Atmospheric N to sensitive ecosystems, like Adirondacks, may increase acidification soils through losses exchangeable nutrient cations, and surface waters associated with enhanced mobility nitrate (NO3−). However, watershed attributes, including surficial terrestrial characteristics, in-lake processing, geological settings, have been found complicate relationships between drainage losses. We studied two lake-watersheds Grass Pond Constable Pond, which are located close proximity (∼26 km) receive similarly high deposition, but contrasting attributes (e.g. wetland area, settings). Since difference influence was minimal, we were able examine both within- between-watershed influences land cover, contribution glacial till groundwater inputs, processes on water chemistry particular emphasis solutes dissolved organic carbon (DOC). Monthly samples at seven inlets one outlet each lake collected from May October 1999 2000. concentrations NO3− inlets, especially major solute inlets. likely weathering products (i.e. Si, Ca2+, Mg2+, Na+) as well acid neutralizing capacity pH values, also particularly those suggesting a large inputs. Dissolved (DON) higher DON DOC attributed area watershed. DOC/DON ratios possibly due larger proportion coniferous forest area. Although strongly related, stronger relationship suggests that additional factors regulate DON. aggregated representation physical features elevation, mean topographic index, hypsometric-analysis index) not clearly related chemistry. Despite distinctive differences inlet chemistry, outlets lakes similar. lower having upstream ponds suggest importance processing sources within lakes. an inverse has suggested be indicative gradient, existence this for sites similar ratio is derived environmental factors. Our results that, despite wet sites, entering affected by hydrology presence wetlands, whereas leaving influenced processing. Copyright © 2006 John Wiley & Sons, Ltd.