Brüggemann, N.

Meier, R.

Schnitzler, J.P.

Steigner, D.

Zimmer, I.

Schnitzler, J. P.

KITopen

IMK-IFU Garmisch-PartenkirchenDr. Nicolas Brüggemann | IMK-IFU | JESIUM 2008, Giens, FranceKIT – a Cooperation betweenKarlsruhe Research Centerand University of KarlsruheAerobic methane emission from grey poplar (Populus x canescens)Nicolas Brüggemann*, Rudolf Meier*, Dominik Steigner*, Ina Zimmer, Jörg-Peter Schnitzler*Center of Stable Isotopes (CSI)Karlsruhe Research CenterInstitute of Meteorology and Climate ResearchAtmospheric Environmental Research (IMK-IFU)Garmisch-PartenkirchenGermanyIMK-IFU Garmisch-PartenkirchenDr. Nicolas Brüggemann | IMK-IFU | JESIUM 2008, Giens, FranceKIT – a Cooperation betweenKarlsruhe Research Centerand University of KarlsruheIMK-IFU Garmisch-PartenkirchenDr. Nicolas Brüggemann | IMK-IFU | JESIUM 2008, Giens, FranceKIT – a Cooperation betweenKarlsruhe Research Centerand University of Karlsruhe• CH4 emission from intact plant material 1–2 orders of magnitude higher than from detached plant material• CH4 emission in sun light 3-5 times higher than in dark• CH4 unusually depleted in 13C• CH4 source strength of 62–236 Tg yr-1 for livingplants and 1–7 Tg yr-1 for plant litter, i.e. 10–30% of the global annual CH4 emissions• However, most measurements performed in CH4-free airIMK-IFU Garmisch-PartenkirchenDr. Nicolas Brüggemann | IMK-IFU | JESIUM 2008, Giens, FranceKIT – a Cooperation betweenKarlsruhe Research Centerand University of KarlsruheReactions of the international research communityIMK-IFU Garmisch-PartenkirchenDr. Nicolas Brüggemann | IMK-IFU | JESIUM 2008, Giens, FranceKIT – a Cooperation betweenKarlsruhe Research Centerand University of KarlsruheMethodology of follow-up experimentsDueck et al. (2007)• basil, sage, wheat, maize grown under 13CO2 atmosphere from seeds• potential 13CH4 emission measured with photoacoustic instrument• observed no significant methane emissionBeerling et al. (2008)• maize and tobacco, grown under normal CO2 in a greenhouse• potential 13CH4 emission measured with FID and leaf cuvettes• observed no significant methane emissionIMK-IFU Garmisch-PartenkirchenDr. Nicolas Brüggemann | IMK-IFU | JESIUM 2008, Giens, FranceKIT – a Cooperation betweenKarlsruhe Research Centerand University of KarlsruheOur experimental design• Plant species: grey poplar (Populus x canescens, syn. Populustremula x P. alba), derived from cell cultures under sterile conditions• Plants on sterile medium in gas-tight flasks in CH4-free air• Headspace was exchanged with synthetic air containing 20% of oxygen and 385 ppm 13CO2 (99 at% 13C)• Flasks were kept in glove box filled with pure N2 for 33 days undera 16/8 h light/dark regimeIMK-IFU Garmisch-PartenkirchenDr. Nicolas Brüggemann | IMK-IFU | JESIUM 2008, Giens, FranceKIT – a Cooperation betweenKarlsruhe Research Centerand University of KarlsruheDays after 13CO2 addition0 7 33CH4 mixing ratio [ppbv]050100150200250 empty medium medium + plants aabababc abcbc bccdACH4 formationCH4 release rate from plants (mean, ± SE)0-7 days: 0.55±0.39 ng g-1 dw h-17-33 days: 0.21±0.11 ng g-1 dw h-10-33 days: 0.25±0.07 ng g-1 dw h-1n = 6, ± SEIMK-IFU Garmisch-PartenkirchenDr. Nicolas Brüggemann | IMK-IFU | JESIUM 2008, Giens, FranceKIT – a Cooperation betweenKarlsruhe Research Centerand University of KarlsruheDays after 13CO2 addition0 7 33-40-30-20-10010203040 emptymedium medium & plantsδ13C of methane [‰ vs. V-PDB] cbaba a aa aaBδ13C of CH4IMK-IFU Garmisch-PartenkirchenDr. Nicolas Brüggemann | IMK-IFU | JESIUM 2008, Giens, FranceKIT – a Cooperation betweenKarlsruhe Research Centerand University of KarlsruheRelationship between δ13C-CH4and δ13C of bulk plant materialδ13C of bulk plant material [‰ vs. V-PDB]180 200 220 240 260 280 300 320δ13C of CH4 [‰ vs. V-PDB]-40-20020406080100rr2 = 0.612P = 0.118y = 1.28 x - 300.59 IMK-IFU Garmisch-PartenkirchenDr. Nicolas Brüggemann | IMK-IFU | JESIUM 2008, Giens, FranceKIT – a Cooperation betweenKarlsruhe Research Centerand University of KarlsruheSummary• Keppler et al. (2006) reported on substantial aerobic CH4 emissionfrom plants and calculated a contribution of 10-30% of this newsource to the global methane budget• So far, other research groups failed to detect aerobic methaneemission from plants significantly different from zero• We have observed CH4 release from poplar significantly different from zero and isotopically labelled• However, the observed emission was 3 orders of magnitude loweras reported by Keppler et al. (2006)• Possible other reasons for high atmospheric methane concentrationsin the tropics: anaerobic methane formation in the soil, transport of CH4 via the transpiration stream and release through the leaves

Aerobic methane emission from grey poplar (Populus x canescens)

https://publikationen.bibliothek.kit.edu/230073247/3815324

Aerobic methane emission from grey poplar (Populus x canescens)

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