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Title
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Soil [N] modulates soil C cycling in -fumigated tree stands : a meta-analysis
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Author
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Abstract
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| Under elevated atmospheric CO2 concentrations, soil carbon (C) inputs are typically enhanced, suggesting larger soil C sequestration potential. However, soil C losses also increase and progressive nitrogen (N) limitation to plant growth may reduce the CO2 effect on soil C inputs with time. We compiled a data set from 131 manipulation experiments, and used meta-analysis to test the hypotheses that: (1) elevated atmospheric CO2 stimulates soil C inputs more than C losses, resulting in increasing soil C stocks; and (2) that these responses are modulated by N. Our results confirm that elevated CO2 induces a C allocation shift towards below-ground biomass compartments. However, the increased soil C inputs were offset by increased heterotrophic respiration (Rh), such that soil C content was not affected by elevated CO2. Soil N concentration strongly interacted with CO2 fumigation: the effect of elevated CO2 on fine root biomass and production and on microbial activity increased with increasing soil N concentration, while the effect on soil C content decreased with increasing soil N concentration. These results suggest that both plant growth and microbial activity responses to elevated CO2 are modulated by N availability, and that it is essential to account for soil N concentration in C cycling analyses. |
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Language
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English
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Source (journal)
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Plant, cell and environment. - Oxford, 1978, currens
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Publication
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Oxford
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Blackwell
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2010
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ISSN
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0140-7791
[print]
1365-3040
[online]
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Volume/pages
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33
:12
(2010)
, p. 2001-2011
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ISI
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000284166500001
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Full text (Publisher's DOI)
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Full text (publisher's version - intranet only)
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