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Titel |
The dynamic of the annual carbon allocation to wood in European tree species is consistent with a combined source–sink limitation of growth: implications for modelling |
VerfasserIn |
J. Guillemot, N. K. Martin-StPaul, E. Dufrêne, C. François, K. Soudani, J. M. Ourcival, N. Delpierre |
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. 9 ; Nr. 12, no. 9 (2015-05-11), S.2773-2790 |
Datensatznummer |
250117930
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Publikation (Nr.) |
copernicus.org/bg-12-2773-2015.pdf |
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Zusammenfassung |
The extent to which wood growth is limited by carbon (C) supply (i.e. source
control) or by cambial activity (i.e. sink control) will strongly determine
the responses of trees to global changes. Nevertheless, the physiological
processes that are responsible for limiting forest growth are still a matter of debate.
The aim of this study was to evaluate the key determinants of the annual C
allocation to wood along large soil and climate regional gradients over
France. The study was conducted for five tree species representative of the
main European forest biomes (Fagus sylvatica, Quercus
petraea, Quercus ilex, Quercus robur and Picea
abies).
The drivers of stand biomass growth were assessed on both inter-site and
inter-annual scales. Our data set comprised field measurements performed at
49 sites (931 site-years) that included biometric measurements and a variety
of stand characteristics (e.g. soil water holding capacity, leaf area
index). It was complemented with process-based simulations when possible
explanatory variables could not be directly measured (e.g. annual and
seasonal tree C balance, bioclimatic water stress indices). Specifically,
the relative influences of tree C balance (source control), direct
environmental control (water and temperature controls of sink activity) and
allocation adjustments related to age, past climate conditions, competition
intensity and soil nutrient availability on growth were quantified.
The inter-site variability in the stand C allocation to wood was
predominantly driven by age-related decline. The direct effects of
temperature and water stress on sink activity (i.e. effects independent
from their effects on the C supply) exerted a strong influence on the annual
stand wood growth in all of the species considered, including deciduous
temperate species. The lagged effect of the past environmental conditions
(e.g. the previous year's water stress and low C uptake) significantly
affected the annual C allocation to wood. The C supply appeared to strongly
limit growth only in temperate deciduous species.
We provide an evaluation of the spatio-temporal dynamics of the annual C
allocation to wood in French forests. Our study supports the premise that
the growth of European tree species is subject to complex control processes
that include both source and sink limitations. The relative influences of
the growth drivers strongly vary with time and across spatial ecological
gradients. We suggest a straightforward modelling framework with which to
implement these combined forest growth limitations into terrestrial
biosphere models. |
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