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| Titel |
Soil surface CO2 flux increases with successional time in a fire scar chronosequence of Canadian boreal jack pine forest |
| VerfasserIn |
D. R. Smith, J. D. Kaduk, H. Balzter, M. J. Wooster, G. N. Mottram, G. Hartley, T. J. Lynham, J. Studens, J. Curry, B. J. Stocks |
| 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 ; 7, no. 5 ; Nr. 7, no. 5 (2010-05-03), S.1375-1381 |
| Datensatznummer |
250004759
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| Publikation (Nr.) |
 copernicus.org/bg-7-1375-2010.pdf |
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| Zusammenfassung |
| To fully understand the carbon (C) cycle impacts of forest fires, both C
emissions during the fire and post-disturbance fluxes need to be considered.
The latter are dominated by soil surface CO2 flux (Fs), which is
still subject to large uncertainties. Fire is generally regarded as the most
important factor influencing succession in the boreal forest biome and fire
dependant species such as jack pine are widespread. In May 2007, we took
concurrent Fs and soil temperature (Ts) measurements in boreal
jack pine fire scars aged between 0 and 59 years since fire. To allow
comparisons between scars, we adjusted Fs for Ts (FsT)
using a Q10 of 2. Mean FsT ranged from 0.56 (± 0.30 sd)
to 1.94 (± 0.74 sd) μmol CO2 m−2 s−1. Our results
indicate a difference in mean FsT between recently burned (4 to 8
days post fire) and non-burned mature (59 years since fire) forest (P < 0.001), though no difference was detected between recently burned
(4 to 8 days post fire) and
non-burned young (16 years since fire) forest (P = 0.785). There was a
difference in mean FsT between previously young (16 years since
fire) and intermediate aged (32 years since fire) scars that were both
subject to fire in 2007 (P < 0.001). However, there was no difference in mean
FsT between mature (59 years since fire) and intermediate aged (32 years since
fire) scars that were both subjected to fire in 2007 (P = 0.226).
Furthermore, there was no difference in mean FsT between mature (59 years since
fire) and young scars (16 years since fire) that were both subjected to fire
in 2007 (P = 0.186). There was an increase in FsT with time since
fire for the chronosequence 0, 16 and 59 years post fire (P < 0.001). Our
results lead us to hypothesise that the autotrophic:heterotrophic soil
respiration ratio increases over post-fire successional time in boreal
jack pine systems, though this should be explored in future research. The
results of this study contribute to a better quantitative understanding of
Fs in boreal jack pine fire scars and will facilitate meta-analyses of
Fs in fire scar chronosequences. |
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