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| Titel |
Above- and belowground fluxes of CH4 from boreal shrubs and Scots pine |
| VerfasserIn |
Elisa Halmeenmäki, Jussi Heinonsalo, Minna Santalahti, Anuliina Putkinen, Hannu Fritze, Mari Pihlatie |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250132186
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| Publikation (Nr.) |
 EGU/EGU2016-12669.pdf |
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| Zusammenfassung |
| Boreal upland forests are considered as an important sink for the greenhouse gas methane
(CH4) due to CH4 oxidizing microbes in the soil. However, recent evidence suggests that
vegetation can act as a significant source of CH4. Also, preliminary measurements indicate
occasional emissions of CH4 above the tree canopies of a boreal forest. Nevertheless, the
sources and the mechanisms of the observed CH4 emissions are still mostly unknown.
Furthermore, the majority of CH4 flux studies have been conducted with the soil chamber
method, thus not considering the role of the vegetation itself. We conducted a laboratory
experiment to study separately the above- and belowground CH4 fluxes of bilberry
(Vaccinium myrtillus), lingonberry (Vaccinium vitis-idaea), heather (Calluna vulgaris), and
Scots pine (Pinus sylvestris), which were grown in microcosms. The above- and belowground
fluxes of the plants were measured separately, and these fluxes were compared to fluxes of
microcosms containing only humus soil. In addition to the flux measurements, we
analysed the CH4 producing archaea (methanogens) and the CH4 consuming bacteria
(methanotrophs) with the qPCR method to discover whether these microbes contribute
to the CH4 exchange from the plant material and the soil. The results of the flux
measurements indicate that the humus soil with roots of lingonberry, heather, and Scots pine
consume CH4 compared to bare humus soil. Simultaneously, the shoots of heather
and Scots pine emit small amounts of CH4. We did not find detectable amounts of
methanogens from any of the samples, suggesting the produced CH4 could be of
non-microbial origin, or produced by very small population of methanogens. Based on
the first preliminary results, methanotrophs were present in all the studied plant
species, and especially in high amounts in the rooted soils, thus implying that the
methanotrophs could be responsible of the CH4 uptake in the root-soil systems. |
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