Workpackage Net ecosystem CO₂ exchange

Workpackage manager: Dr. Torben CHRISTENSEN

Objectives:
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 CO^₂ exchange (cf. WP 4).
  

Deliverables:

• 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
  

Milestones:

• 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