Workpackage Net ecosystem CO2 exchange

Workpackage manager: Dr. Torben CHRISTENSEN

Aim of WP 1 is to provide estimates of the annual net ecosystem carbon exchange of differently managed European mountain ecosystems and their seasonal and inter-annual variability.

Methodology / work description:

  • Continuous measurements of net ecosystem exchange (NEE) will be made employing the Eddy-Covariance
    technique at least at one plot in each study site which satisfies the requirements of the Eddy-Covariance (EC) method (terrain, slope, fetch).
  • At sites where the assumptions underlying the EC method are violated, alternative techniques such as the
    Bowen-Ratio-Energy-Balance (BREB) method and chamber techniques will be employed.
  • The validity of night time EC flux measurements will be assessed using chamber methods.
  • Flux measurements will be accompanied by continuous measurements of the environmental driving forces (above and below-ground).
  • Data gaps will be filled following the guide lines for gap filling developed in existing flux networks and by means of a process-oriented model of ecosystem CO2 exchange (cf. WP 4).


  • Annual sums, seasonal and inter-annual variability of NEE
  • Effects of land use/management on NEE
  • Effects of climatic conditions on NEE
  • Comparison of NEE of non forest and adjacent forest ecosystems (from other projects)
  • Cross-calibration of micrometeorological and chamber methods


  • 1st year carbon budgets
  • 2nd year carbon budgets, comparison with 1st year
  • Assessment of the factors controlling seasonal and inter-annual variability of NEE
  • Assessment of the effects of land use on NEE
  • Assessment of effects of differing climatic conditions between study sites on NEE