DOI: 10.5061/dryad.4gk00
title: Data from: Influence of natural and novel organic carbon sources on denitrification in forest, degraded urban, and restored streams

description: Organic carbon is important in regulating ecosystem function, and its
 source and abundance may be altered by urbanization. We investigated
 shifts in organic carbon quantity and quality associated with urbanization
 and ecosystem restoration, and its potential effects on denitrification at
 the riparian–stream interface. Field measurements of streamwater
 chemistry, organic carbon characterization, and laboratory-based
 denitrification experiments were completed at two forested, two restored,
 and two unrestored urban streams at the Baltimore Long-Term Ecological
 Research site, Maryland, USA. Dissolved organic carbon (DOC) and nitrate
 loads increased with runoff according to a power-law function that varied
 across sites. Stable isotopes and molar C:N ratios suggested that stream
 particulate organic matter (POM) was a mixture of periphyton, leaves, and
 grass that varied across site types. Stable-isotope signatures and lipid
 biomarker analyses of sediments showed that terrestrial organic carbon
 sources in streams varied as a result of riparian vegetation. Laboratory
 experiments indicated that organic carbon amendments significantly
 increased rates of denitrification (35.1 ± 9.4 ng N·[g dry
 sediment]−1·h−1; mean ± SE) more than nitrate amendments (10.4 ± 4.0 ng
 N·[g dry sediment]−1·h−1) across streamflow conditions and sites.
 Denitrification experiments with naturally occurring carbon sources showed
 that denitrification was significantly higher with grass clippings from
 home lawns (1244 ± 331 ng N·g dry sediment−1·h−1), and overall unrestored
 urban sites showed significantly higher denitrification rates than
 restored and forest sites. We found that urbanization influences organic
 carbon sources and quality in streams, which can have substantial
 downstream impacts on ecosystem services such as denitrification.
description: Newcomer et al. 2012
 (Ecological Monographs) Organic C and Denitrification in
 StreamsThe file “Newcomer et
 al. 2012 (Ecological Monographs) Organic C and Denitrification in
 Streams.xlsx” provides original data from the manuscript. The worksheets
 are named to correspond with the figures in the manuscript. “Figure 4” has
 field measurements of nitrate and DOC loads (g ha-1 day-1) and runoff (mm
 day-1). We measured discharge at Spring Branch and discharge was
 downloaded from USGS gaging stations at the other sites. “Figure 5” was
 created using discharge (cfs) downloaded from USGS gaging stations and
 dividing it by watershed area to get runoff (mm day-1). “Figure 6” has
 field measurements of mean C:N molar ratios for leaves, periphyton, grass,
 sediment, and stream particulate organic matter (POM). “Figure 7” has
 field measurements of 15N and 13C stable isotope signatures for leaves,
 periphyton, grass, sediment, and stream POM. “Figure 8” has laboratory
 measurements of denitrification potentials associated with glucose versus
 nitrate amendments. “Figure 9” has laboratory measurements of
 denitrification potentials associated with the use of leaves, periphyton,
 and grass as a carbon source.