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Introduction
More than 0.8 M ha of forestry-drained peatlands in Finland are considered low-productive. The sites are mostly initially treeless or very sparsely treed fens and poor transitional pine mires in the aapa mire region, and pine bogs in the south (SB) and mid boreal (MB) Finland (Fig. 1). There is a growing interest in restoring these sites but not much is known about the impacts of restoration measures on greenhouse gas (GHG) fluxes. LIFEPeatLandUse (EU Life+ Environment) increases the knowledge base on the impacts of peatland re-use on ecosystem services.
This study presents preliminary results of site-type specific fluxes of
CH4 and CO2 for restored, drained and drained + fertilized sites, as
measured from June/July until mid-October 2014 using closed dark
chambers for both gases, and a portable IR-based analyzer (EGM4,
PP-systems) for CO2 fluxes. CH4 fluxes were calculated as a linear
change in CH4 concentrations (CG analytics) from four consequent
samples during a sampling period of 20 minutes.
Results
Methane Fluxes
- High methane emissions from blocked or filled ditches of restored
mesotrophic and oligotrophic sites, and other wet surfaces of the
sites in the aapa mire region (Fig. 2).
- Low CH4 fluxes from hummock surfaces in all sites.
- In SB bogs, clear emissions were detected only from ditches.
Soil CO2 respiration
- Total soil respiration (SR) (R from litter and peat decomposition
+ live ground vegetation and tree roots) averaged 0.39, 0.38, and
0.48 g CO2 m-2 h-1 in all sites of SB, MB, and aapa mire regions,
respectively (Fig. 3a).
- Heterotrophic SR (fresh plant litter, live vegetation and tree roots
excluded by trenching in spring 2014) averaged 0.18, 0.21, and
0.29 g CO2 m-2 h-1 in SB, MB, and aapa mire regions (Fig. 3b).
- Compared to merely drained sites, the drained + fertilized sites
showed higher and rewetted sites lower fluxes in all regions and
trophic levels for both total and heterotrophic respiration, as
expected.
Fig 1. Location of GHG measurement sites in the Action B3 of the LIFEPeatLandUse project,
and an example of measurements at Tolkansuo, Vaala (aapa mire region).
Restoration of low-productive,
forestry-drained peatlands - impacts
on CO2 and CH4 fluxes
Contact: 1) Natural Resources Institute (Luke), [email protected], [email protected], [email protected] 2) University of Helsinki, [email protected], [email protected], 3) Natural Heritage Services of Metsähallitus, [email protected]
Timo Penttilä1, Mari Keränen1,2, Miia Parviainen1, Paavo Ojanen2, Tuomas Haapalehto3
and Kari Minkkinen2
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ditch hummock lawn_wet ditch hummock lawn_wet ditch hummock lawn_wet
MESO OLIGO OMBRO
g C
H4 m
-2 h
-1
AAPA - drained
AAPA - fertilized
AAPA - restored
MB - drained
MB - fertilized
MB - restored
SB - drained
SB - restored
Fig 2. Average, momentary CH4 fluxes from different surfaces of drained, drained+ fertilized,
and rewetted peatland sites, by region and trophic level, in 2014.
Fig 3. Average, momentary CO2 fluxes from (a) total, and (b) heterotrophic soil respiration in 2014.
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hummock lawn_wet hummock lawn_wet hummock lawn_wet
MESO OLIGO OMBRO
g C
O2 m
-2 h
-1 AAPA - drained
AAPA - fertilized
AAPA - restored
MB - drained
MB - fertilized
MB - restored
SB - drained
SB - restored
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hummock lawn_wet hummock lawn_wet hummock lawn_wet
MESO OLIGO OMBRO
g C
O2 m
-2 h
-1 AAPA - drained
AAPA - fertilized
AAPA - restored
MB - drained
MB - fertilized
MB - restored
SB - drained
SB - restored
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