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| Titel |
Impacts of prescribed burning on soil greenhouse gas fluxes in a suburban native forest of south-eastern Queensland, Australia |
| VerfasserIn |
Y. Zhao, Y. Z. Wang, Z. H. Xu, L. Fu |
| 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. 21 ; Nr. 12, no. 21 (2015-11-03), S.6279-6290 |
| Datensatznummer |
250118150
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| Publikation (Nr.) |
 copernicus.org/bg-12-6279-2015.pdf |
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| Zusammenfassung |
| Prescribed burning is a forest
management practice that is widely used in Australia to reduce the risk of
damaging wildfires. Prescribed burning can affect both carbon (C) and
nitrogen (N) cycling in the forest and thereby influence the soil-atmosphere
exchange of major greenhouse gases, i.e. carbon dioxide (CO2), methane
(CH4) and nitrous oxide (N2O). To quantify the impact of a
prescribed burning (conducted on 27 May 2014) on greenhouse gas exchange and
the potential controlling mechanisms, we carried out a series of field
measurements before (August 2013) and after (August 2014 and November 2014)
the fire. Gas exchange rates were determined in four replicate plots which were
burned during the combustion and in another four adjacent unburned plots located
in green islands, using a set of static chambers. Surface soil properties
including temperature, pH, moisture, soil C and N pools were also determined
either by in situ measurement or by analysing surface 10 cm soil samples.
All of the chamber measurements indicated a net sink of atmospheric CH4,
with mean CH4 uptake ranging from 1.15 to 1.99 mg m−2 d−1.
Prescribed burning significantly enhanced CH4 uptake as indicated by the
significant higher CH4 uptake rates in the burned plots measured in
August 2014. In the following 3 months, the CH4 uptake rate was
recovered to the pre-burning level. Mean CO2 emission from the forest
soils ranged from 2721.76 to 7113.49 mg m−2 d−1. The effect of
prescribed burning on CO2 emission was limited within the first 3 months, as no significant difference was observed between the burned and the
adjacent unburned plots in both August and November 2014. The CO2
emissions showed more seasonal variations, rather than the effects of
prescribed burning. The N2O emission in the plots was quite low, and no
significant impact of prescribed burning was observed. The changes in
understory plants and litter layers, surface soil temperature, C and N
substrate availability and microbial activities, following the prescribed
burning, were the factors that controlled the greenhouse gas exchanges. Our
results suggested that the low-intensity prescribed burning would decrease
soil CO2 emission and increase CH4 uptake, but this effect would be
present within a relatively short period. Only slight changes in the surface
soil properties during the combustion and very limited impacts of prescribed
burning on the mineral soils supported the rapid recovery of the greenhouse
gas exchange rates. |
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