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Assessing seasonality of biochemical CO2 exchange model parameters from micrometeorological flux observations at boreal coniferous forest

Thum, T.; Aalto, T.; Laurila, T.; Aurela, M.; Lindroth, Anders LU and Vesala, T. (2008) In Biogeosciences 5(6). p.1625-1639
Abstract
The seasonality of the NEE of the northern boreal coniferous forests was investigated by means of inversion modelling using eddy covariance data. Eddy covariance data was used to optimize the biochemical model parameters. Our study sites consisted of three Scots pine (1. Pinus sylvestris) forests and one Norway spruce (1. Picea abies) forest that were located in Finland and Sweden. We obtained temperature and seasonal dependence for the biochemical model parameters: the maximum rate of carboxylation (V-c(max)) and the maximum rate of electron transport (J(max)). Both of the parameters were optimized without assumptions about their mutual magnitude. The values obtained for the biochemical model parameters were similar at all the sites... (More)
The seasonality of the NEE of the northern boreal coniferous forests was investigated by means of inversion modelling using eddy covariance data. Eddy covariance data was used to optimize the biochemical model parameters. Our study sites consisted of three Scots pine (1. Pinus sylvestris) forests and one Norway spruce (1. Picea abies) forest that were located in Finland and Sweden. We obtained temperature and seasonal dependence for the biochemical model parameters: the maximum rate of carboxylation (V-c(max)) and the maximum rate of electron transport (J(max)). Both of the parameters were optimized without assumptions about their mutual magnitude. The values obtained for the biochemical model parameters were similar at all the sites during summer time. To describe seasonality, different temperature fits were made for the spring, summer and autumn periods. During summer, average Jmax across the sites was 54.0 mu mol m(-2) s(-1) (variance 31.2 mu mol m(-2) s(-1)) and V-c(max) was 12.0 mu mol m(-2) s(-1) (variance 6.6 mu mol m(-2) s(-1)) at 17 degrees C. The sensitivity of the model to LAI and atmospheric soil water stress was also studied. The impact of seasonality on annual GPP was 17% when only summertime parameterization was used throughout the year compared to seasonally changing parameterizations. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Biogeosciences
volume
5
issue
6
pages
1625 - 1639
publisher
Copernicus Publications
external identifiers
  • wos:000262411100012
  • scopus:58049139211
ISSN
1726-4189
language
English
LU publication?
yes
id
21bfcc4d-4d96-4ff9-9abd-d10c6ad0bc39 (old id 1376119)
date added to LUP
2009-05-07 14:34:59
date last changed
2017-06-18 03:46:07
@article{21bfcc4d-4d96-4ff9-9abd-d10c6ad0bc39,
  abstract     = {The seasonality of the NEE of the northern boreal coniferous forests was investigated by means of inversion modelling using eddy covariance data. Eddy covariance data was used to optimize the biochemical model parameters. Our study sites consisted of three Scots pine (1. Pinus sylvestris) forests and one Norway spruce (1. Picea abies) forest that were located in Finland and Sweden. We obtained temperature and seasonal dependence for the biochemical model parameters: the maximum rate of carboxylation (V-c(max)) and the maximum rate of electron transport (J(max)). Both of the parameters were optimized without assumptions about their mutual magnitude. The values obtained for the biochemical model parameters were similar at all the sites during summer time. To describe seasonality, different temperature fits were made for the spring, summer and autumn periods. During summer, average Jmax across the sites was 54.0 mu mol m(-2) s(-1) (variance 31.2 mu mol m(-2) s(-1)) and V-c(max) was 12.0 mu mol m(-2) s(-1) (variance 6.6 mu mol m(-2) s(-1)) at 17 degrees C. The sensitivity of the model to LAI and atmospheric soil water stress was also studied. The impact of seasonality on annual GPP was 17% when only summertime parameterization was used throughout the year compared to seasonally changing parameterizations.},
  author       = {Thum, T. and Aalto, T. and Laurila, T. and Aurela, M. and Lindroth, Anders and Vesala, T.},
  issn         = {1726-4189},
  language     = {eng},
  number       = {6},
  pages        = {1625--1639},
  publisher    = {Copernicus Publications},
  series       = {Biogeosciences},
  title        = {Assessing seasonality of biochemical CO2 exchange model parameters from micrometeorological flux observations at boreal coniferous forest},
  volume       = {5},
  year         = {2008},
}