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Titel |
Effects of free atmospheric CO2 enrichment (FACE), N fertilization and poplar genotype on the physical protection of carbon in the mineral soil of a polar plantation after five years |
VerfasserIn |
M. R. Hoosbeek, J. M. Vos, E. J. Bakker, G. E. Scarascia-Mugnozza |
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 ; 3, no. 4 ; Nr. 3, no. 4 (2006-11-03), S.479-487 |
Datensatznummer |
250001160
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Publikation (Nr.) |
copernicus.org/bg-3-479-2006.pdf |
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Zusammenfassung |
Free air CO2 enrichment (FACE) experiments in aggrading forests and
plantations have demonstrated significant increases in net primary
production (NPP) and C storage in forest vegetation. The extra C uptake may
also be stored in forest floor litter and in forest soil. After five years
of FACE treatment at the EuroFACE short rotation poplar plantation, the
increase of total soil C% was larger under elevated than under ambient
CO2. However, the fate of this additional C allocated belowground
remains unclear. The stability of soil organic matter is controlled by the
chemical structure of the organic matter and the formation of
micro-aggregates (within macro-aggregates) in which organic matter is
stabilized and protected. FACE and N-fertilization treatment did not affect
the micro- and macro-aggregate weight, C or N fractions obtained by wet
sieving. However, Populus euramericana increased the small macro-aggregate and free
micro-aggregate weight and C fractions. The obtained macro-aggregates were
broken up in order to isolate recently formed micro-aggregates within
macro-aggregates (iM-micro-aggregates). FACE increased the
iM-micro-aggregate weight and C fractions, although not significantly. This
study reveals that FACE did not affect the formation of aggregates. We did,
however, observe a trend of increased stabilization and protection of soil C
in micro-aggregates formed within macro-aggregates under FACE. Moreover, the
largest effect on aggregate formation was due to differences in species,
i.e. poplar genotype. P. euramericana increased the formation of free micro-aggregates
which means that more newly incorporated soil C was stabilized and
protected. The choice of species in a plantation, or the effect of global
change on species diversity, may therefore affect the stabilization and
protection of C in soils. |
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