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Abstract Sulfate is a potential pollutant and important nutrient linked with the nitrogen, carbon, and phosphorus cycles. The importance of different anthropogenic sulfate sources in suburban streams (septic systems, fertilizer, road salt, and infrastructure) is uncertain, and the temporal dynamics of stream export sparsely documented. We study sources and export dynamics of sulfate in suburban and forested headwater catchments. Stream baseflow discharge and sulfate concentrations were strongly positively correlated in both watersheds with the highest values in spring. Suburban concentrations and fluxes (2.48–7.5 mg/L or 25.8–78.1 μM, 16.6 kg/ha/yr) were consistently higher than forested (0.56–2.78 mg/L or 5.8–28.9 μM, 5 kg/ha/yr). Following precipitation, sulfate concentrations in both forested and suburban streams increased to concentrations above pre‐storm values and remained high after peak discharge. These dynamics suggest that both catchments have a large pool of sulfate that can be mobilized under wet conditions. Ridge‐top forest soil samples contained 210 kg/ha stored, extractable sulfate. Current atmospheric sulfate deposition rates (5–7 kg/ha/yr) are approximately in balance with sulfate export in the forested stream. In the suburban watershed, we estimated septic fields contribute up to 11 kg/ha/yr (about half from surfactants) and lawn care up to 4.3 kg/ha/yr and are the most likely sources of elevated stream sulfate. Sulfate sulfur (4.9–5.8‰ forested; 6.1–7.0‰ suburban) and oxygen isotope values (0.7–2.0‰ forested; −0.1–4.1‰ suburban) are consistent with this interpretation, but do not provide strong corroboration due to large variation and overlap in estimated source values.
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Appalachian stream length dynamics: shapefiles
{"Abstract":["Wet stream length and connectivity maps for 3 forested catchments (<75 ha) in each of 4 physiographic provinces of the Appalachian Highlands: the New England, Appalachian Plateau, Valley and Ridge, and Blue Ridge. Maps were developed for 12 headwater catchments under 7 different wetness conditions as represented by stream discharge and characterizing conditions between exceedance probabilities of <5% and >90% of the mean daily discharge. The dataset represents a map (shapefile) of the "wet" stream network on 7 different occasions for the 12 catchments. A \u201cwet stream\u201d location applies to visible surface water greater than 1 m in length at a GPS location.\n These data are described in detail and analyzed in: Jensen, C. K., McGuire, K. J., & Prince, P. S. (2017). Headwater stream length dynamics across four physiographic provinces of the Appalachian Highlands. Hydrological Processes, 31(19), 3350-3363."]}
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- Award ID(s):
- 1637685
- PAR ID:
- 10395943
- Publisher / Repository:
- Environmental Data Initiative
- Date Published:
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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