Net ecosystem exchange over heterogeneous Arctic tundra: Scaling between chamber and eddy covariance measurements
Net ecosystem exchange (NEE) was estimated for an area of tundra near Abisko using both eddy covariance (EC) data and chamber measurements. This area of tundra is heterogeneous with six principal elements forming a landscape mosaic. Chamber measurements in patches of the individual mosaic elements w...
Published in: | Global Biogeochemical Cycles |
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Online Access: | http://nora.nerc.ac.uk/id/eprint/3992/ http://www.agu.org/pubs/crossref/2008/2007GB003027.shtml https://doi.org/10.1029/2007GB003027 |
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ftnerc:oai:nora.nerc.ac.uk:3992 2024-06-09T07:37:46+00:00 Net ecosystem exchange over heterogeneous Arctic tundra: Scaling between chamber and eddy covariance measurements Fox, Andrew M. Huntley, Brian Lloyd, Colin R. Williams, Mathew Baxter, Robert 2008 http://nora.nerc.ac.uk/id/eprint/3992/ http://www.agu.org/pubs/crossref/2008/2007GB003027.shtml https://doi.org/10.1029/2007GB003027 unknown Fox, Andrew M.; Huntley, Brian; Lloyd, Colin R.; Williams, Mathew; Baxter, Robert. 2008 Net ecosystem exchange over heterogeneous Arctic tundra: Scaling between chamber and eddy covariance measurements. Global Biogeochemical Cycles, 22, GB2027. https://doi.org/10.1029/2007GB003027 <https://doi.org/10.1029/2007GB003027> Meteorology and Climatology Ecology and Environment Atmospheric Sciences Publication - Article PeerReviewed 2008 ftnerc https://doi.org/10.1029/2007GB003027 2024-05-15T08:46:53Z Net ecosystem exchange (NEE) was estimated for an area of tundra near Abisko using both eddy covariance (EC) data and chamber measurements. This area of tundra is heterogeneous with six principal elements forming a landscape mosaic. Chamber measurements in patches of the individual mosaic elements were used to model NEE as a function of irradiance and temperature. The area around the EC mast was mapped, and a footprint model was used to simulate the varying source fraction attributable to each mosaic element. Various upscaling approaches were used to estimate NEE for comparison with NEE calculated from the EC observations. The results showed that EC measurements made for such a heterogeneous site are robust to the variations in NEE between mosaic elements that also vary substantially in their source fractions. However, they also revealed a large (∼60%) bias in the absolute magnitude of the cumulative negative NEE for a 40-day study period simulated by various upscaling approaches when compared to the value calculated from the EC observations. The magnitude of this bias, if applied to estimates for the entire tundra region, is substantial in relation to other components of the global carbon budget. Various hypotheses to account for this bias are discussed and, where possible, evaluated. A need is identified for more systematic sampling strategies when performing chamber measurements in order to assess the extent to which subjectivity of chamber location may account for much of the observed bias. If this is the origin of the bias, then upscaling approaches using chamber measurements may generally overestimate CO2 uptake. Article in Journal/Newspaper Abisko Arctic Arctic Tundra Natural Environment Research Council: NERC Open Research Archive Abisko ENVELOPE(18.829,18.829,68.349,68.349) Arctic Global Biogeochemical Cycles 22 2 n/a n/a |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
topic |
Meteorology and Climatology Ecology and Environment Atmospheric Sciences |
spellingShingle |
Meteorology and Climatology Ecology and Environment Atmospheric Sciences Fox, Andrew M. Huntley, Brian Lloyd, Colin R. Williams, Mathew Baxter, Robert Net ecosystem exchange over heterogeneous Arctic tundra: Scaling between chamber and eddy covariance measurements |
topic_facet |
Meteorology and Climatology Ecology and Environment Atmospheric Sciences |
description |
Net ecosystem exchange (NEE) was estimated for an area of tundra near Abisko using both eddy covariance (EC) data and chamber measurements. This area of tundra is heterogeneous with six principal elements forming a landscape mosaic. Chamber measurements in patches of the individual mosaic elements were used to model NEE as a function of irradiance and temperature. The area around the EC mast was mapped, and a footprint model was used to simulate the varying source fraction attributable to each mosaic element. Various upscaling approaches were used to estimate NEE for comparison with NEE calculated from the EC observations. The results showed that EC measurements made for such a heterogeneous site are robust to the variations in NEE between mosaic elements that also vary substantially in their source fractions. However, they also revealed a large (∼60%) bias in the absolute magnitude of the cumulative negative NEE for a 40-day study period simulated by various upscaling approaches when compared to the value calculated from the EC observations. The magnitude of this bias, if applied to estimates for the entire tundra region, is substantial in relation to other components of the global carbon budget. Various hypotheses to account for this bias are discussed and, where possible, evaluated. A need is identified for more systematic sampling strategies when performing chamber measurements in order to assess the extent to which subjectivity of chamber location may account for much of the observed bias. If this is the origin of the bias, then upscaling approaches using chamber measurements may generally overestimate CO2 uptake. |
format |
Article in Journal/Newspaper |
author |
Fox, Andrew M. Huntley, Brian Lloyd, Colin R. Williams, Mathew Baxter, Robert |
author_facet |
Fox, Andrew M. Huntley, Brian Lloyd, Colin R. Williams, Mathew Baxter, Robert |
author_sort |
Fox, Andrew M. |
title |
Net ecosystem exchange over heterogeneous Arctic tundra: Scaling between chamber and eddy covariance measurements |
title_short |
Net ecosystem exchange over heterogeneous Arctic tundra: Scaling between chamber and eddy covariance measurements |
title_full |
Net ecosystem exchange over heterogeneous Arctic tundra: Scaling between chamber and eddy covariance measurements |
title_fullStr |
Net ecosystem exchange over heterogeneous Arctic tundra: Scaling between chamber and eddy covariance measurements |
title_full_unstemmed |
Net ecosystem exchange over heterogeneous Arctic tundra: Scaling between chamber and eddy covariance measurements |
title_sort |
net ecosystem exchange over heterogeneous arctic tundra: scaling between chamber and eddy covariance measurements |
publishDate |
2008 |
url |
http://nora.nerc.ac.uk/id/eprint/3992/ http://www.agu.org/pubs/crossref/2008/2007GB003027.shtml https://doi.org/10.1029/2007GB003027 |
long_lat |
ENVELOPE(18.829,18.829,68.349,68.349) |
geographic |
Abisko Arctic |
geographic_facet |
Abisko Arctic |
genre |
Abisko Arctic Arctic Tundra |
genre_facet |
Abisko Arctic Arctic Tundra |
op_relation |
Fox, Andrew M.; Huntley, Brian; Lloyd, Colin R.; Williams, Mathew; Baxter, Robert. 2008 Net ecosystem exchange over heterogeneous Arctic tundra: Scaling between chamber and eddy covariance measurements. Global Biogeochemical Cycles, 22, GB2027. https://doi.org/10.1029/2007GB003027 <https://doi.org/10.1029/2007GB003027> |
op_doi |
https://doi.org/10.1029/2007GB003027 |
container_title |
Global Biogeochemical Cycles |
container_volume |
22 |
container_issue |
2 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1801375100001320960 |