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Titel |
Response of carbon dioxide emissions to sheep grazing and N application in an alpine grassland – Part 1: Effect of sheep grazing |
VerfasserIn |
Y. M. Gong, A. Mohammat, X. J. Liu, K. H. Li, P. Christie, F. Fang, W. Song, Y. H. Chang, W. X. Han, X. T. Lü, Y. Y. Liu, Y. K. Hu |
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 ; 11, no. 7 ; Nr. 11, no. 7 (2014-04-03), S.1743-1750 |
Datensatznummer |
250117338
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Publikation (Nr.) |
copernicus.org/bg-11-1743-2014.pdf |
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Zusammenfassung |
Previous work has failed to address fully the response of (autotrophic and
heterotrophic) respiration to grazing in different ecosystems, particularly
in alpine grasslands outside the growing season. From 2010 to 2011 a field
experiment combined two methods (static closed chambers and a closed dynamic
soil CO2 flux system) in alpine grasslands located in the Tianshan
Mountains. We examined the effects of grazing regime on ecosystem respiration
(Re) both outside (NGS) and during (GS) the growing season and
determined the pattern of Re in relation to climate change. There
was no significant change in CO2 emissions under grazing. Heterotrophic
respiration (Rh) accounted for 78.5% of Re with
short-term grazing exclusion and 93.2% of Re with long-term
grazing exclusion. Re, Rh and autotrophic respiration
(Ra) fluxes outside the growing season were equivalent to
12.9%, 14.1% and 11.4% of the respective CO2 fluxes
during the growing season. In addition, our results indicate that soil water
content played a critical role in Ra in the cold and arid
environment. Both Rh and Re were sensitive to soil
temperature. Moreover, our results suggest that grazing exerted no
significant effect on CO2 emissions in these alpine grasslands. |
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