In:
Journal of Marine Research, Journal of Marine Research/Yale, Vol. 73, No. 3 ( 2015-05-01), p. 71-92
Abstract:
Nitrous oxide (N 2 O) is important to Earth's climate because it is a strong absorber of radiation and an important ozone depletion agent. Increasing anthropogenic nitrogen input into the marine environment, especially to coastal waters, has led to increasing N 2 O
emissions. Identifying the nitrogen compounds that serve as substrates for N 2 O production in coastal waters reveals important pathways and helps us understand their control by environmental factors. In this study, sediments were collected from a long-term fertilization site in Great Sippewissett Marsh, Falmouth, Massachusetts. The 15 N tracer incubation time course experiments were conducted and analyzed for potential N 2 O production and consumption rates. The two nitrogen substrates of N 2 O production, ammonium and nitrate, correspond to
the two production pathways, nitrification and denitrification, respectively. When measurable nitrate was present, despite ambient high ammonium concentrations, denitrification was the major N 2 O production pathway. When nitrate was absent, ammonium became the dominant substrate
for N 2 O production, via nitrification and coupled nitrification-denitrification. Net N 2 O consumption was enhanced under low oxygen and nitrate conditions. N 2 O production and consumption rates increased with increasing levels of nitrogen fertilization in long-term
experimental plots. These results indicate that increasing anthropogenic nitrogen input to salt marshes can stimulate sedimentary N 2 O production via both nitrification and denitrification, whereas episodic oxygen depletion results in net N 2 O consumption.
Type of Medium:
Online Resource
ISSN:
0022-2402
DOI:
10.1357/002224015815848820
Language:
English
Publisher:
Journal of Marine Research/Yale
Publication Date:
2015
detail.hit.zdb_id:
410655-6
detail.hit.zdb_id:
2066603-2
SSG:
12
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