Dataset Information

Cumulative response of ecosystem carbon and nitrogen stocks to chronic CO? exposure in a subtropical oak woodland.

ABSTRACT: Rising atmospheric carbon dioxide (CO?) could alter the carbon (C) and nitrogen (N) content of ecosystems, yet the magnitude of these effects are not well known. We examined C and N budgets of a subtropical woodland after 11 yr of exposure to elevated CO?. We used open-top chambers to manipulate CO? during regrowth after fire, and measured C, N and tracer (15) N in ecosystem components throughout the experiment. Elevated CO? increased plant C and tended to increase plant N but did not significantly increase whole-system C or N. Elevated CO? increased soil microbial activity and labile soil C, but more slowly cycling soil C pools tended to decline. Recovery of a long-term (15) N tracer indicated that CO? exposure increased N losses and altered N distribution, with no effect on N inputs. Increased plant C accrual was accompanied by higher soil microbial activity and increased C losses from soil, yielding no statistically detectable effect of elevated CO? on net ecosystem C uptake. These findings challenge the treatment of terrestrial ecosystems responses to elevated CO? in current biogeochemical models, where the effect of elevated CO? on ecosystem C balance is described as enhanced photosynthesis and plant growth with decomposition as a first-order response.

SUBMITTER: Hungate BA

PROVIDER: S-EPMC4282374 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature

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Cumulative response of ecosystem carbon and nitrogen stocks to chronic CO₂ exposure in a subtropical oak woodland.

Hungate Bruce A BA Dijkstra Paul P Wu Zhuoting Z Duval Benjamin D BD Day Frank P FP Johnson Dale W DW Megonigal J Patrick JP Brown Alisha L P ALP Garland Jay L JL

The New phytologist 20130530 3

Rising atmospheric carbon dioxide (CO₂) could alter the carbon (C) and nitrogen (N) content of ecosystems, yet the magnitude of these effects are not well known. We examined C and N budgets of a subtropical woodland after 11 yr of exposure to elevated CO₂. We used open-top chambers to manipulate CO₂ during regrowth after fire, and measured C, N and tracer (15) N in ecosystem components throughout the experiment. Elevated CO₂ increased plant C and tended to increase plant N but did not significan ...[more]

PMID: 23718224

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Dataset Information

Cumulative response of ecosystem carbon and nitrogen stocks to chronic CO? exposure in a subtropical oak woodland.

Publications

Cumulative response of ecosystem carbon and nitrogen stocks to chronic CO₂ exposure in a subtropical oak woodland.

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