Advanced

A catchment-scale carbon and greenhouse gas budget of a subartic landscape

Christensen, Torben LU ; Johansson, Torbjörn LU ; Olsrud, Maria LU ; Ström, Lena LU ; Lindroth, Anders LU ; Mastepanov, Mikhail LU ; Malmer, Nils LU ; Friborg, Thomas; Crill, Patrick and Callaghan, Terry V. (2007) In Royal Society of London. Philosophical Transactions A. Mathematical, Physical and Engineering Sciences 365(1856). p.1643-1656
Abstract
This is the first attempt to budget average current annual carbon (C) and associated greenhouse gas (GHG) exchanges and transfers in a subarctic landscape, the Lake Torneträsk catchment in northern Sweden. This is a heterogeneous area consisting of almost 4000 km2 of mixed heath, birch and pine forest, and mires, lakes and alpine ecosystems. The magnitudes of atmospheric exchange of carbon in the form of the GHGs, CO2 and CH4 in these various ecosystems differ significantly, ranging from little or no flux in barren ecosystems over a small CO2 sink function and low rates of CH4 exchange in the heaths to significant CO2 uptake in the forests and also large emissions of CH4 from the mires and small lakes. The overall catchment budget, given... (More)
This is the first attempt to budget average current annual carbon (C) and associated greenhouse gas (GHG) exchanges and transfers in a subarctic landscape, the Lake Torneträsk catchment in northern Sweden. This is a heterogeneous area consisting of almost 4000 km2 of mixed heath, birch and pine forest, and mires, lakes and alpine ecosystems. The magnitudes of atmospheric exchange of carbon in the form of the GHGs, CO2 and CH4 in these various ecosystems differ significantly, ranging from little or no flux in barren ecosystems over a small CO2 sink function and low rates of CH4 exchange in the heaths to significant CO2 uptake in the forests and also large emissions of CH4 from the mires and small lakes. The overall catchment budget, given the size distribution of the individual ecosystem types and a first approximation of run-off as dissolved organic carbon, reveals a landscape currently with a significant sink capacity for atmospheric CO2. This sink capacity is, however, extremely sensitive to environmental changes, particularly those that affect the birch forest ecosystem. Climatic drying or wetting and episodic events such as insect outbreaks may cause significant changes in the sink function. Changes in the sources of CH4 through increased permafrost melting may also easily change the sign of the current radiative forcing, due to the stronger impact per gram of CH4 relative to CO2. Hence, to access impacts on climate, the atmospheric C balance alone has to be weighed in a radiative forcing perspective. When considering the emissions of CH4 from the mires and lakes as CO2 equivalents, the Torneträsk catchment is currently a smaller sink of radiative forcing, but it can still be estimated as representing the equivalent of approximately 14 000 average Swedish inhabitants' emissions of CO2. This can be compared with the carbon emissions of less than 200 people who live permanently in the catchment, although this comparison disregards substantial emissions from the non-Swedish tourism and transportation activities. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
carbon budgets, greenhouse gas emissions, catchment studies, carbon dioxide, methane
in
Royal Society of London. Philosophical Transactions A. Mathematical, Physical and Engineering Sciences
volume
365
issue
1856
pages
1643 - 1656
publisher
Royal Society
external identifiers
  • scopus:34547366490
  • wos:000247780800002
ISSN
1364-503X
DOI
10.1098/rsta.2007.2035
language
English
LU publication?
yes
id
64877510-4904-49a5-ac29-36ded456bbc4 (old id 709106)
date added to LUP
2007-12-14 11:03:44
date last changed
2017-11-05 03:33:39
@article{64877510-4904-49a5-ac29-36ded456bbc4,
  abstract     = {This is the first attempt to budget average current annual carbon (C) and associated greenhouse gas (GHG) exchanges and transfers in a subarctic landscape, the Lake Torneträsk catchment in northern Sweden. This is a heterogeneous area consisting of almost 4000 km2 of mixed heath, birch and pine forest, and mires, lakes and alpine ecosystems. The magnitudes of atmospheric exchange of carbon in the form of the GHGs, CO2 and CH4 in these various ecosystems differ significantly, ranging from little or no flux in barren ecosystems over a small CO2 sink function and low rates of CH4 exchange in the heaths to significant CO2 uptake in the forests and also large emissions of CH4 from the mires and small lakes. The overall catchment budget, given the size distribution of the individual ecosystem types and a first approximation of run-off as dissolved organic carbon, reveals a landscape currently with a significant sink capacity for atmospheric CO2. This sink capacity is, however, extremely sensitive to environmental changes, particularly those that affect the birch forest ecosystem. Climatic drying or wetting and episodic events such as insect outbreaks may cause significant changes in the sink function. Changes in the sources of CH4 through increased permafrost melting may also easily change the sign of the current radiative forcing, due to the stronger impact per gram of CH4 relative to CO2. Hence, to access impacts on climate, the atmospheric C balance alone has to be weighed in a radiative forcing perspective. When considering the emissions of CH4 from the mires and lakes as CO2 equivalents, the Torneträsk catchment is currently a smaller sink of radiative forcing, but it can still be estimated as representing the equivalent of approximately 14 000 average Swedish inhabitants' emissions of CO2. This can be compared with the carbon emissions of less than 200 people who live permanently in the catchment, although this comparison disregards substantial emissions from the non-Swedish tourism and transportation activities.},
  author       = {Christensen, Torben and Johansson, Torbjörn and Olsrud, Maria and Ström, Lena and Lindroth, Anders and Mastepanov, Mikhail and Malmer, Nils and Friborg, Thomas and Crill, Patrick and Callaghan, Terry V.},
  issn         = {1364-503X},
  keyword      = {carbon budgets,greenhouse gas emissions,catchment studies,carbon dioxide,methane},
  language     = {eng},
  number       = {1856},
  pages        = {1643--1656},
  publisher    = {Royal Society},
  series       = {Royal Society of London. Philosophical Transactions A. Mathematical, Physical and Engineering Sciences},
  title        = {A catchment-scale carbon and greenhouse gas budget of a subartic landscape},
  url          = {http://dx.doi.org/10.1098/rsta.2007.2035},
  volume       = {365},
  year         = {2007},
}