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Titel |
N2O fluxes from the littoral zone of a Chinese reservoir |
VerfasserIn |
M. Yang, X. M. Geng, J. Grace, Y. F. Jia, Y. Z. Liu, S. W. Jiao, L. L. Shi, C. Lu, Y. Zhou, G. C. Lei |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 12, no. 15 ; Nr. 12, no. 15 (2015-08-06), S.4711-4723 |
Datensatznummer |
250118054
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Publikation (Nr.) |
copernicus.org/bg-12-4711-2015.pdf |
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Zusammenfassung |
There have been few studies of greenhouse gas emissions from reservoirs,
despite the remarkable growth in the number of reservoirs in developing
countries. We report a case study that focuses on the littoral zone of a
major Chinese reservoir, where we established measurements of N2O fluxes
using the static chamber technique at five different water levels (deep
water, shallow water, seasonally flooded, control for seasonally flooded, and
non-flooded). The "control for seasonal flooded" had similar vegetation to
the "seasonally flooded" but was not actually flooded as it was on a higher
piece of land. Seasonal, diurnal and spatial variations of N2O flux and
environmental factors were monitored throughout the growing season which
included a flood event during summer rains. The N2O flux ranged from
−136.6 to 381.8 μg m−2 h−1 averaging
6.8 μg m−2 h−1. Seasonal and spatial variation was
significant but diurnal variation was not. Non-flooded dry land emitted more
N2O than flooded land, no matter whether it was permanently or
seasonally flooded. Piecewise correlation was found between N2O flux,
air temperature and soil nitrate concentration. Positive correlation was
shown between N2O flux and dissolved oxygen in water. There were
significantly higher emissions from farmland. We compared these results with
our recently published study of CH4 emissions, carried out
simultaneously at the same site as those in the present study. Completely
different patterns between the two gases are demonstrated. We conclude that
the littoral zone is a hotspot for N2O emissions in the summer,
especially when the shores of the lake are used for the farming of maize. But
in terms of the overall greenhouse gas budget, the fluxes of N2O are not
as important as those of CH4. |
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