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Bearing the brunt of warming: Interactions between carbon and hydrology in northern Sweden

MZOBE, Pearl LU (2021)
Abstract
Climate modelling studies indicate that subarctic ecosystems are predicted to show some of the earliest responses to climate change. The predicted temperature and precipitation changes have implications for the carbon biogeochemical cycle with ancillary effects in permafrost soils, vegetation, and stream networks. Browning, a result of changes in dissolved organic carbon (DOC) export to river systems, has been marked as an early indicator of climate-induced changes in northern freshwaters. The release of DOC in to rivers and atmosphere has the potential to further increase the emissions of greenhouse gasses. The reintroduction of old carbon is not limited to atmospheric interactions as the lateral flux of carbon at the terrestrial-aquatic... (More)
Climate modelling studies indicate that subarctic ecosystems are predicted to show some of the earliest responses to climate change. The predicted temperature and precipitation changes have implications for the carbon biogeochemical cycle with ancillary effects in permafrost soils, vegetation, and stream networks. Browning, a result of changes in dissolved organic carbon (DOC) export to river systems, has been marked as an early indicator of climate-induced changes in northern freshwaters. The release of DOC in to rivers and atmosphere has the potential to further increase the emissions of greenhouse gasses. The reintroduction of old carbon is not limited to atmospheric interactions as the lateral flux of carbon at the terrestrial-aquatic interface is further affected by warming. Parts of the subarctic region are host to permafrost soils, which serve as a store of frozen soil organic carbon. Climatic changes threaten to turn these regions from carbon sinks to carbon sources. Active layer deepening, a result of precipitation and temperature changes in permafrost zones, is a source of increasing greenhouse gas (CO2 and CH4) emissions. Changes in of permafrost areas spurs changes in catchment land cover and ecosystem function.

This study was conducted in a subarctic catchment with mixed vegetation cover and a permafrost thaw gradient to understand the spatio-temporal changes in the biogeochemical cycle. The Normalized Vegetation Difference Index (NDVI), together with easily available topographical indices, was used to model the DOC release into streams using GIS analysis and linear regression methods.

The results of this research show that DOC is concentrated in the low-lying areas of Stordalen catchment. The distribution of DOC was largely controlled by topographic factors, in particular slope and the presence of mires. This study points to a largely unexplored potential of using geospatial analysis methods to capture and represent responses to climate change. Applying geospatial techniques provides a first step spatio-temporal approach to present phase shifts in the broader scale of catchment carbon cycling.
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Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor McIntyre, Sally, University of California, Santa Barbera
organization
publishing date
type
Thesis
publication status
published
subject
keywords
dissoved organic carbon (DOC), carbon flux, permafrost thaw, hydrological connectivity, GIS analysis
pages
180 pages
publisher
Media-Tryck, Lund University, Sweden
defense location
Pangea, Lund Join via zoom: https://lu-se.zoom.us/j/62094023285
defense date
2021-09-09 15:00:00
ISBN
978-91-89187-07-8
978-91-89187-08-5
language
English
LU publication?
yes
id
e228b3f5-c70f-457d-b552-80f423431eb5
date added to LUP
2021-07-02 15:30:28
date last changed
2021-08-16 15:15:08
@phdthesis{e228b3f5-c70f-457d-b552-80f423431eb5,
  abstract     = {{Climate modelling studies indicate that subarctic ecosystems are predicted to show some of the earliest responses to climate change. The predicted temperature and precipitation changes have implications for the carbon biogeochemical cycle with ancillary effects in permafrost soils, vegetation, and stream networks. Browning, a result of changes in dissolved organic carbon (DOC) export to river systems, has been marked as an early indicator of climate-induced changes in northern freshwaters. The release of DOC in to rivers and atmosphere has the potential to further increase the emissions of greenhouse gasses. The reintroduction of old carbon is not limited to atmospheric interactions as the lateral flux of carbon at the terrestrial-aquatic interface is further affected by warming. Parts of the subarctic region are host to permafrost soils, which serve as a store of frozen soil organic carbon. Climatic changes threaten to turn these regions from carbon sinks to carbon sources. Active layer deepening, a result of precipitation and temperature changes in permafrost zones, is a source of increasing greenhouse gas (CO2 and CH4) emissions. Changes in of permafrost areas spurs changes in catchment land cover and ecosystem function.<br/><br/>This study was conducted in a subarctic catchment with mixed vegetation cover and a permafrost thaw gradient to understand the spatio-temporal changes in the biogeochemical cycle. The Normalized Vegetation Difference Index (NDVI), together with easily available topographical indices, was used to model the DOC release into streams using GIS analysis and linear regression methods. <br/><br/>The results of this research show that DOC is concentrated in the low-lying areas of Stordalen catchment. The distribution of DOC was largely controlled by topographic factors, in particular slope and the presence of mires. This study points to a largely unexplored potential of using geospatial analysis methods to capture and represent responses to climate change. Applying geospatial techniques provides a first step spatio-temporal approach to present phase shifts in the broader scale of catchment carbon cycling.<br/>}},
  author       = {{MZOBE, Pearl}},
  isbn         = {{978-91-89187-07-8}},
  keywords     = {{dissoved organic carbon (DOC); carbon flux; permafrost thaw; hydrological connectivity; GIS analysis}},
  language     = {{eng}},
  publisher    = {{Media-Tryck, Lund University, Sweden}},
  school       = {{Lund University}},
  title        = {{Bearing the brunt of warming: Interactions between carbon and hydrology in northern Sweden}},
  year         = {{2021}},
}