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Titel |
Increased phosphorus availability mitigates the inhibition of nitrogen deposition on CH4 uptake in an old-growth tropical forest, southern China |
VerfasserIn |
T. Zhang, W. Zhu, J. Mo, L. Liu, S. Dong |
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 ; 8, no. 9 ; Nr. 8, no. 9 (2011-09-29), S.2805-2813 |
Datensatznummer |
250006137
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Publikation (Nr.) |
copernicus.org/bg-8-2805-2011.pdf |
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Zusammenfassung |
It is well established that tropical forest ecosystems are often limited by
phosphorus (P) availability, and elevated atmospheric nitrogen (N)
deposition may further enhance such P limitation. However, it is uncertain
whether P availability would affect soil fluxes of greenhouse gases, such as
methane (CH4) uptake, and how P interacts with N deposition. We examine
the effects of N and P additions on soil CH4 uptake in an N saturated
old-growth tropical forest in southern China to test the following
hypotheses: (1) P addition would increase CH4 uptake; (2) N addition
would decrease CH4 uptake; and (3) P addition would mitigate the
inhibitive effect of N addition on soil CH4 uptake. Four treatments
were conducted at the following levels from February 2007 to October 2009:
control, N-addition (150 kg N ha−1 yr−1), P-addition (150 kg P ha−1 yr−1),
and NP-addition (150 kg N ha−1 yr−1 plus 150 kg P ha−1 yr−1). Static chamber and gas chromatography techniques
were used to quantify soil CH4 uptake every month throughout the study
period. Average CH4 uptake rate was 31.2 ± 1.1 μg CH4-C m−2 h−1 in the control plots. The mean CH4 uptake rate in the
N-addition plots was 23.6 ± 0.9 μg CH4-C m−2 h−1,
significantly lower than that in the controls. P-addition however,
significantly increased CH4 uptake by 24% (38.8 ± 1.3 μg CH4-C m−2 h−1),
whereas NP-addition (33.6 ± 1.0 μg CH4-C m−2 h−1) was not statistically different from the
control. Our results suggest that increased P availability may enhance soil
mathanotrophic activity and root growth, resulting in potentially mitigating
the inhibitive effect of N deposition on CH4 uptake in tropical forests. |
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