Inorganic nitrogen retention by watersheds at Fernow Experimental Forest and Coweeta Hydrologic Laboratory

摘要: Because elevated N loading can impair both terrestrial and aquatic ecosystems, understanding the abiotic biotic controls over retention export of dissolved inorganic (DIN) is crucial. Long-term research has been conducted on experimental watersheds at two U.S. Forest Service forests in Appalachian region: Fernow Experimental (FEF) West Virginia Coweeta Hydrologic Laboratory (CHL) North Carolina. While similar vegetation history, FEF CHL differ climate, historic DIN deposition, soils. We evaluated long-term patterns inputs exports from three each location with treatments including clear-cut harvest, conversion to conifer plantation (Norway spruce [Picea abies (L.) H. Karst.] white pine [Pinus strobus L.] CHL), as well reference watersheds. examined these watersheds, comparing treated within forest similarly between forests. Despite current levels stream water concentrations were generally greater by almost an order magnitude. found differences concentrations, watershed export, not only untreated but also disturbance treatment. hypothesize that are result site history deposition. document switch biogeochemical hydrologic occurred when availability exceeded immobilization, due either deposition or biological inputs.