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| Titel |
Carbon and greenhouse gas balances in an age sequence of temperate pine plantations |
| VerfasserIn |
M. Peichl, A. M. Arain, T. R. Moore, J. J. Brodeur, M. Khomik, S. Ullah, N. Restrepo-Coupe, J. McLaren, M. R. Pejam |
| 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 ; 11, no. 19 ; Nr. 11, no. 19 (2014-10-07), S.5399-5410 |
| Datensatznummer |
250117625
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| Publikation (Nr.) |
 copernicus.org/bg-11-5399-2014.pdf |
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| Zusammenfassung |
| This study investigated differences in the magnitude and partitioning of the
carbon (C) and greenhouse gas (GHG) balances in an age sequence of four white
pine (Pinus strobus L.) afforestation stands (7, 20, 35 and 70 years
old as of 2009) in southern Ontario, Canada. The 4-year (2004–2008) mean
annual carbon dioxide (CO2) exchanges, based on biometric and eddy
covariance data, were combined with the 2-year means of static chamber
measurements of methane (CH4) and nitrous oxide (N2O) fluxes
(2006–2007) and dissolved organic carbon (DOC) export below 1 m soil depth
(2004–2005). The total ecosystem C pool increased with age from 46 to
197 t C ha−1 across the four stands. Rates of organic matter cycling
(i.e. litterfall and decomposition) were similar among the three older
stands. In contrast, considerable differences related to stand age and site
quality were observed in the magnitude and partitioning of individual
CO2 fluxes, showing a peak in production and respiration rates in the
middle-age (20-year-old) stand growing on fertile post-agricultural soil. The
DOC export accounted for 10% of net ecosystem production (NEP) at the
7-year-old stand but <2% at the three older stands. The GHG balance
from the combined exchanges of CO2, CH4 and N2O was 2.6, 21.6,
13.5 and 4.8 t CO2 equivalent ha−1 year−1 for the 7-, 20-,
35- and 70-year-old stands, respectively. The maximum annual contribution
from the combined exchanges of CH4 and N2O to the GHG balance was
13 and 8% in the 7- and 70-year-old stands, respectively, but
<1% in the two highly productive middle-age (20- and 35-year-old)
stands. Averaged over the entire age sequence, the CO2 exchange was the
main driver of the GHG balance in these forests. The cumulative CO2
sequestration over the 70 years was estimated at 129 t C and
297 t C ha−1 year−1 for stands growing on low- and
high-productivity sites, respectively. This study highlights the importance
of accounting for age and site quality effects on forest C and GHG balances.
It further demonstrates a large potential for net C sequestration and climate
benefits gained through afforestation of marginal agricultural and fallow
lands in temperate regions. |
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