Amy J. Burgin

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© The Ecological Society of America E nitrogen (N) concentrations, often in the form of nitrate, present a water-quality problem of growing concern. Nitrate concentrations in groundwater and rivers in developed areas of the world have risen substantially as a result of the use of synthetic N fertilizers and cultivation of N-fixing(More)
Anthropogenic addition of bioavailable nitrogen to the biosphere is increasing and terrestrial ecosystems are becoming increasingly nitrogen-saturated, causing more bioavailable nitrogen to enter groundwater and surface waters. Large-scale nitrogen budgets show that an average of about 20-25 per cent of the nitrogen added to the biosphere is exported from(More)
Nitrous oxide (N(2)O) is a potent greenhouse gas that contributes to climate change and stratospheric ozone destruction. Anthropogenic nitrogen (N) loading to river networks is a potentially important source of N(2)O via microbial denitrification that converts N to N(2)O and dinitrogen (N(2)). The fraction of denitrified N that escapes as N(2)O rather than(More) © The Ecological Society of America A organisms have to make a living by harnessing energy, collecting nutrients, and expelling waste. The joining together, or coupling, of elemental cycles occurs when elements required for biosynthesis are assimilated into microbial, plant, and animal biomass, and again when that biomass is(More)
There is great uncertainty about the fate of nitrogen (N) added to urban and suburban lawns. We used direct flux and in situ chamber methods to measure N and NO fluxes from lawns instrumented with soil O sensors. We hypothesized that soil O, moisture, and available NO were the most important controls on denitrification and that N and NO fluxes would be high(More)
Salinization, a widespread threat to the structure and ecological functioning of inland and coastal wetlands, is currently occurring at an unprecedented rate and geographic scale. The causes of salinization are diverse and include alterations to freshwater flows, land-clearance, irrigation, disposal of wastewater effluent, sea level rise, storm surges, and(More)
[1] Wetland soil oxygen (O2) is rarely measured, which limits our understanding of a key regulator of nitrogen loss through denitrification. We asked: (1) How does soil [O2] vary in riparian wetlands? (2) How does this [O2] variation affect denitrification rates and end products? and (3) How does [O2] variation and previous exposure to O2 affect trace gas(More)
We measured denitrification rates using a field 15N–NO 3 tracer-addition approach in a large, cross-site study of nitrate uptake in reference, agricultural, and suburban–urban streams. We measured denitrification rates in 49 of 72 streams studied. Uptake length due to denitrification (SWden) ranged from 89 m to 184 km (median of 9050 m) and there were no(More)
I contemporary society, scientists hold a considerable degree of respect, trust, admiration, and authority. Surveys show that North American and European citizens hold a deep belief in the promise of science to solve problems, as well as to improve quality of life and the economy (Eurobarometer 2008; NSB 2008; Pew Research Center on People and the Press(More)
Evaluating nitrate-N fluxes from agricultural landscapes is inherently complex due to the wide range of intrinsic and dynamic controlling variables. In this study, we investigate the influence of contrasting antecedent moisture conditions on nitrate-N flux magnitude and dynamics in a single agricultural watershed on intra-annual and rainfall-event temporal(More)