The role of stoichiometric flexibility in modelling forest ecosystem responses to nitrogen fertilization
© 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.
Veröffentlicht in: | The New phytologist. - 1979. - 208(2015), 4 vom: 27. Dez., Seite 1042-55 |
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Format: | Online-Aufsatz |
Sprache: | English |
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2015
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Zugriff auf das übergeordnete Werk: | The New phytologist |
Schlagworte: | Journal Article Research Support, Non-U.S. Gov't carbon-nitrogen cycle coupling ecosystem modelling fertilization forest carbon balance nitrogen cycle plant stoichiometry Fertilizers Soil mehr... |
Zusammenfassung: | © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust. The response of the forest carbon (C) balance to changes in nitrogen (N) deposition is uncertain, partly owing to diverging representations of N cycle processes in dynamic global vegetation models (DGVMs). Here, we examined how different assumptions about the degree of flexibility of the ecosystem's C : N ratios contribute to this uncertainty, and which of these assumptions best correspond to the available data. We applied these assumptions within the framework of a DGVM and compared the results to responses in net primary productivity (NPP), leaf N concentration, and ecosystem N partitioning, observed at 22 forest N fertilization experiments. Employing flexible ecosystem pool C : N ratios generally resulted in the most convincing model-data agreement with respect to production and foliar N responses. An intermediate degree of stoichiometric flexibility in vegetation, where wood C : N ratio changes were decoupled from leaf and root C : N ratio changes, led to consistent simulation of production and N cycle responses to N addition. Assuming fixed C : N ratios or scaling leaf N concentration changes to other tissues, commonly assumed by DGVMs, was not supported by reported data. Between the tested assumptions, the simulated changes in ecosystem C storage relative to changes in C assimilation varied by up to 20% |
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Beschreibung: | Date Completed 06.09.2016 Date Revised 30.09.2020 published: Print-Electronic Citation Status MEDLINE |
ISSN: | 1469-8137 |
DOI: | 10.1111/nph.13547 |