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Titel |
Influence of wood density in tree-ring-based annual productivity assessments and its errors in Norway spruce |
VerfasserIn |
O. Bouriaud, M. Teodosiu, A. V. Kirdyanov, C. Wirth |
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 ; 12, no. 20 ; Nr. 12, no. 20 (2015-10-29), S.6205-6217 |
Datensatznummer |
250118145
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Publikation (Nr.) |
copernicus.org/bg-12-6205-2015.pdf |
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Zusammenfassung |
Estimations of tree annual biomass increments are used by a variety of
studies related to forest productivity or carbon fluxes. Biomass increment
estimations can be easily obtained from diameter surveys or historical
diameter reconstructions based on tree rings' records. However, the biomass
models rely on the assumption that wood density is constant. Converting volume
increment into biomass also requires assumptions about the wood density. Wood
density has been largely reported to vary both in time and between trees. In
Norway spruce, wood density is known to increase with decreasing ring width.
This could lead to underestimating the biomass or carbon deposition in bad
years. The variations between trees of wood density have never been discussed
but could also contribute to deviations. A modelling approach could
attenuate these effects but will also generate errors.
Here a model of wood density variations in Norway spruce, and
an allometric model of volume growth were developed. We accounted for variations in wood
density both between years and between trees, based on specific
measurements. We compared the effects of neglecting each variation source on
the estimations of annual biomass increment. We also assessed the errors of
the biomass increment predictions at tree level, and of the annual
productivity at plot level.
Our results showed a partial compensation of the decrease in ring width in
bad years by the increase in wood density. The underestimation of the
biomass increment in those years reached 15 %. The errors related to the
use of an allometric model of volume growth were modest, around ±15 %. The errors related to variations in wood density were much larger,
the biggest component being the inter-tree variability. The errors in
plot-level annual biomass productivity reached up to 40 %, with a full
account of all the error sources. |
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