influence of ground water table level on methane emissions from tree stems in a forestry-drained fen
TRANSCRIPT
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INFLUENCE OF GROUND WATER TABLE DEPTH ON METHANE EMISSIONS FROM
TREE STEMS IN A FORESTRY-DRAINED FENMARI PIHLATIE1, IIKKA HAIKARAINEN1, ELISA HALMEENMÄKI1, PETTERI
PYYKKÖ1, KATERINA MACHACOVA2, MIKA KORKIAKOSKI3, KARI MINKKINEN4, PAAVO OJANEN5, TIMO PENTTILÄ5, ANNALEA LOHILA3
1University of Helsinki, Department of Physics, 2Global Change Research Centre, Brno, Czech Republic
3Finnish Meteorological Institute, Helsinki, Finland,4University of Helsinki, Department of Forest Sciences,
5Natural Resources Institute Finland.
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Upland forest are a sink of CH4 (methanotrophs)
Despite this, above canopy fluxes show CH4 emissions.
Can trees be the missing source?
MOTIVATION
Among the natural sources, the contribution of vegetation to the global CH4 budget is the least
well understood (Carmischael et al., 2014).
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CAN PINE TREES BE THE MISSING SOURCE OF CH4?
Dry upland soil Machacova et al. (2016), Scientific Reports.
What controls tree-CH4 emissions?
H1: Stem emissions depend on soil water content
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HIGH STEM CH4 EMISSIONS FROM BIRCH IN WETCONDITIONS
Poster, Halmeenmäki et al.
Birch trees as conduits for CH4 produced in the soil?
Pangala et al. (2013): similar flux rates from wetland trees in Southeast Asia
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FIELD EXPERIMENT: THE EFFECT OF GROUNDWATER TABLE ON TREE AND SOIL CH4 EXCHANGE
CH4
CH4
CH4
Water table
CH4
production transport
Partial cut: Letto 1Control: Letto 2
CH4
Pine, spruce, birch Spruce, birch
canopy transpiration↓
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Lettosuo: Drained peatland forest
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CH4 FLUX MEASUREMENTS
Manual stem chambers (UGGA, ultraportable greenhouse gas analyzer, LGR)- 5 chambers / tree species / siteAutomatic soil chambers (Picarro G1130) - 6 automatic chambers / site
Stem chamber profiles- 3 chamber heights / tree(birch)
June-August 2016
1.8.2016
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SIGNIFICANT SOIL UPTAKEHIGHERCH4 UPTAKE FROMTHE CONTROL AREA
Partial cut, WT 10cm higher
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SMALL STEM EMISSIONS BIRCHFROM PARTIALLY CUTFOREST
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SMALL STEM EMISSIONS SPRUCE
FROM PARTIALLY CUTFOREST
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BIRCH AND SPRUCE STEMFLUXES DIFFER IN HEIGHT
R1 R2 R3
B. pubescens , MkK
CH
4 -
flux
gh
1m
2
0
20
40
60
80
10099
0.88 0.31
R1 R2 R3
P. abies , MkK
-0.5
0.0
0.5
1.0
1.5
0.52
-0.14
1.1
R1 R2 R3
B. pendula , VT
-8
-6
-4
-2
0
2
4
6
-7.3
-1.6
4.5
Wet soil
Haikarainen et al., in preparation
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R1 R2 R3
B. pubescens , MkK
CH
4 -
flux
gh
1m
2
0
20
40
60
80
10099
0.88 0.31
R1 R2 R3
P. abies , MkK
-0.5
0.0
0.5
1.0
1.5
0.52
-0.14
1.1
R1 R2 R3
B. pendula , VT
-8
-6
-4
-2
0
2
4
6
-7.3
-1.6
4.5
BIRCH AND SPRUCE STEMFLUXES DIFFER IN HEIGHT
Wet soil Wet soil
Haikarainen et al., in preparation
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TAKE HOME AND FUTURE PLANSWe are not talking about teragrams of CH4 from boreal trees, but about a significantlydecreased CH4 sink=> global importance!
More measurements are neededto understand the mechanismsand drivers of CH4 emissions fromtrees => for modelling
Our measurements continueincluding seach for methanogensand methanotrophs, and study of tree anatomical differences
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THANK YOU!
The Emil Aaltonen
Foundation