Workpackage Ecosystem carbon and nitrogen pools


Workpackage manager: Prof. Dr. Pertti HARI


Objectives:
Aim of WP 3 is i) to quantify ecosystem carbon and nitrogen pool sizes and their major components in differently managed mountain ecosystems and ii) to assess their seasonal and inter-annual variability.


Methodology / work description:

  • The soil carbon and nitrogen pools will be determined from soil cores twice a year, separating inorganic pools, roots and remaining soil organic matter (SOM).
  • Above-ground carbon and nitrogen pools will be determined by stratified harvesting at least twice a year, separating the phytomass into living and dead (attached dead and litter), the major plant components (leaves, stems, reproductive organs) and functional groups (forbs, graminoids, legumes, dwarf shrubs). Furthermore, effects of land-use changes on the biomass partitioning of key species will be analysed along an altitudinal an a latitudinal transect, using a combined experimental and modelling approach.
  • Carbon and nitrogen contents will be determined from harvested material using an elemental analyser (CHNS-932, LECO instruments, USA).
  • Litter decomposition will be estimated using the litter bag method.
  • Hemi-surface area indices will be determined from harvested above-ground plant material using an area-meter (Li-3100, LI-Cor, USA). In addition, hemi-surface plant area indices will be determined in a non-destructive fashion bi-weekly during the vegetation period using optical sensors (Ci-110, CID, USA; SunScan, Delta T, UK) and inverse-modelling of radiative transfer.


Deliverables:

  • Size of ecosystem carbon and nitrogen pools and their major components and their seasonal and inter-annual variability
  • General (altitudinal and latitudinal) relationships between plant biomass partitioning and land-use changes
  • Long-term data sets for litter decomposition
  • Seasonal variation of hemi-surface plant area indices
  • Data sets of stratified plant area index and phytomass and its components


Milestones:

  • Size of ecosystem carbon and nitrogen pools and their major components for the 1st year
  • Size of ecosystem carbon and nitrogen pools and their major components for the 2nd year
  • Seasonal and inter-annual variability of major ecosystem carbon and nitrogen pools and hemi-surface plant area indices