Greenhouse gases flux dynamics and controlling environmental factors in Northern wetlands
(2026)- Abstract
- Methane (CH₄) and carbon dioxide (CO₂) emissions from northern peatlands are
important components of the global greenhouse gas (GHG) balance and are highly
sensitive to climate change and permafrost degradation. This thesis investigates
spatial and temporal patterns of GHG fluxes across peatland ecosystems, with a
particular focus on the environmental controls regulating CH₄ and CO₂ exchange.
Field measurements were conducted across Swedish peatlands using chamber
systems and eddy covariance observations. Chamber measurements were used to
study small-scale spatial variability in CH₄ fluxes and supported isotopic analyses
of CH₄. Ecosystem-scale flux data from the ICOS Sweden station at Abisko-
Stordalen... (More) - Methane (CH₄) and carbon dioxide (CO₂) emissions from northern peatlands are
important components of the global greenhouse gas (GHG) balance and are highly
sensitive to climate change and permafrost degradation. This thesis investigates
spatial and temporal patterns of GHG fluxes across peatland ecosystems, with a
particular focus on the environmental controls regulating CH₄ and CO₂ exchange.
Field measurements were conducted across Swedish peatlands using chamber
systems and eddy covariance observations. Chamber measurements were used to
study small-scale spatial variability in CH₄ fluxes and supported isotopic analyses
of CH₄. Ecosystem-scale flux data from the ICOS Sweden station at Abisko-
Stordalen were used to quantify annual GHG budgets across contrasting permafrost
landforms, including palsa, thawing permafrost areas, and fully thawed fens. The
study further evaluated how environmental drivers such as peat temperature,
hydrology, light availability, and growing season length influence carbon exchange
dynamics.
The thesis also examines methodological challenges in peatland GHG research. In
particular, the role of gap-filling approaches in reducing uncertainties and
highlighting the importance of methodological choices for reliable annual budget
estimates. In addition, stable isotope analyses (δ¹³C-CH₄) were used to explore
whether peatland CH₄ processes and carbon dynamics can be adequately
represented by single isotopic value. Temporal and spatial variations in isotopic
composition were linked to environmental conditions, substrate availability, and
microbial community composition.
The results demonstrate that permafrost thaw strongly make changes in carbon
cycling in peatlands by increasing CH₄ emissions and modifying CO₂ exchange
patterns. Fully thawed systems showed greater CO₂ uptake during the growing
season, but also higher ecosystem respiration rates, compared with palsa and
partially thawed systems. CH₄ emissions were primarily controlled by peat
temperature and hydrological conditions, while CO₂ dynamics were more strongly
linked to growing season length and light availability. Furthermore, the findings
emphasize that both spatial heterogeneity and methodological decisions
significantly influence the interpretation of peatland carbon dynamics and GHG
budgets.
By integrating flux measurements, isotopic analyses, and methodological
evaluation, this thesis provides new insights into the controls on GHG emissions in
northern peatlands undergoing climate warming, extreme events such as drought
and permafrost degradation. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/0588504d-fee8-4a6f-bebf-932f2868fe0d
- author
- Lakomiec, Patryk LU
- supervisor
-
- Janne Rinne LU
- Jutta Holst LU
- opponent
-
- Professor K. Varner, Ruth, University of New Hampshire, the US.
- organization
- publishing date
- 2026
- type
- Thesis
- publication status
- published
- subject
- keywords
- Greenhouse gases, wetlands, eddy covariance, chamber measurements, isotopic composition, controlling factors
- pages
- 76 pages
- publisher
- Department of Earth and Environmental Sciences, Lund University
- defense location
- Pangea, Geocentrum II, Sölvegatan 12, Lund. Join via zoom: https://lu-se.zoom.us/j/66564712345
- defense date
- 2026-09-10 09:00:00
- ISBN
- 978-91-90202-71-5
- 978-91-90202-72-2
- project
- MEthane goes MObile - MEasurements and MOdelling
- language
- English
- LU publication?
- yes
- id
- 0588504d-fee8-4a6f-bebf-932f2868fe0d
- date added to LUP
- 2026-08-13 11:49:51
- date last changed
- 2026-08-18 08:35:14
@phdthesis{0588504d-fee8-4a6f-bebf-932f2868fe0d,
abstract = {{Methane (CH₄) and carbon dioxide (CO₂) emissions from northern peatlands are<br/>important components of the global greenhouse gas (GHG) balance and are highly<br/>sensitive to climate change and permafrost degradation. This thesis investigates<br/>spatial and temporal patterns of GHG fluxes across peatland ecosystems, with a<br/>particular focus on the environmental controls regulating CH₄ and CO₂ exchange.<br/>Field measurements were conducted across Swedish peatlands using chamber<br/>systems and eddy covariance observations. Chamber measurements were used to<br/>study small-scale spatial variability in CH₄ fluxes and supported isotopic analyses<br/>of CH₄. Ecosystem-scale flux data from the ICOS Sweden station at Abisko-<br/>Stordalen were used to quantify annual GHG budgets across contrasting permafrost<br/>landforms, including palsa, thawing permafrost areas, and fully thawed fens. The<br/>study further evaluated how environmental drivers such as peat temperature,<br/>hydrology, light availability, and growing season length influence carbon exchange<br/>dynamics.<br/>The thesis also examines methodological challenges in peatland GHG research. In<br/>particular, the role of gap-filling approaches in reducing uncertainties and<br/>highlighting the importance of methodological choices for reliable annual budget<br/>estimates. In addition, stable isotope analyses (δ¹³C-CH₄) were used to explore<br/>whether peatland CH₄ processes and carbon dynamics can be adequately<br/>represented by single isotopic value. Temporal and spatial variations in isotopic<br/>composition were linked to environmental conditions, substrate availability, and<br/>microbial community composition.<br/>The results demonstrate that permafrost thaw strongly make changes in carbon<br/>cycling in peatlands by increasing CH₄ emissions and modifying CO₂ exchange<br/>patterns. Fully thawed systems showed greater CO₂ uptake during the growing<br/>season, but also higher ecosystem respiration rates, compared with palsa and<br/>partially thawed systems. CH₄ emissions were primarily controlled by peat<br/>temperature and hydrological conditions, while CO₂ dynamics were more strongly<br/>linked to growing season length and light availability. Furthermore, the findings<br/>emphasize that both spatial heterogeneity and methodological decisions<br/>significantly influence the interpretation of peatland carbon dynamics and GHG<br/>budgets.<br/>By integrating flux measurements, isotopic analyses, and methodological<br/>evaluation, this thesis provides new insights into the controls on GHG emissions in<br/>northern peatlands undergoing climate warming, extreme events such as drought<br/>and permafrost degradation.}},
author = {{Lakomiec, Patryk}},
isbn = {{978-91-90202-71-5}},
keywords = {{Greenhouse gases; wetlands; eddy covariance; chamber measurements; isotopic composition; controlling factors}},
language = {{eng}},
publisher = {{Department of Earth and Environmental Sciences, Lund University}},
school = {{Lund University}},
title = {{Greenhouse gases flux dynamics and controlling environmental factors in Northern wetlands}},
url = {{https://lup.lub.lu.se/search/files/257945367/e-spik_ex_Patryk.pdf}},
year = {{2026}},
}