HIKET Work Packages

This work package assesses the representativeness of the current carbon flux measurement network and identifies the key needs for its expansion.

Based on this assessment, the network will be complemented with additional stations using the eddy covariance method. These stations will measure the exchange of carbon dioxide, and when relevant, also methane and nitrous oxide between ecosystems and the atmosphere.

A total of five to six new measurement stations will be established. The aim is to build an optimized observation network that supports greenhouse gas balance assessments across the main land-use categories, ensuring adequate ecosystem diversity, regional coverage, and model calibration capacity.

Expanding the measurement network will also provide a long-term foundation for reducing uncertainties in the national land use sector carbon balance estimates.

In this work package, we make extensive use of both existing and newly produced measurement data and models to assess the greenhouse gas (GHG) balance of terrestrial ecosystems in Finland. The measurement data include not only inventory information but also satellite observations, concentration data from tall towers, and gas exchange data obtained using the eddy covariance method. The models in use are also diverse: some describe vegetation, soil, and atmospheric processes, gas transport, and data assimilation, while others are based on empirical statistical analysis.

This work package also refines the National Forest Inventory (NFI)–based calculations used as part of the national GHG inventory. We investigate the causes behind the changes in NFI canopy biomass expansion factors by assessing the variation in the relationship between canopy biomass and volume using different methods within a selected test area. In addition, we evaluate changes in the deadwood carbon stock based on measurements from permanent NFI sample plots and compare them with the current model-based estimates.

The main goal of this work package is to build a comprehensive understanding of the GHG balance and its uncertainties. We compare GHG balance estimates produced with different methods and determine the range of variation between them. It is important to note that various measurement data and models operate on different scales, meaning that method comparison must also be conducted across multiple spatial and temporal scales. We also aim to identify the key factors contributing to uncertainty in each method.

Furthermore, the work package explores the feasibility of developing a broader uncertainty analysis process for the national GHG balance. The results obtained will also be compared with the current national GHG inventory to assess potential areas for improvement and development opportunities.

In this work package, the focus is on harmonising greenhouse gas measurements and measurement data processing, as well as developing the national research infrastructure. The aim is to ensure that the measurement datasets produced by different actors (University of Helsinki, FMI, LUKE) are comparable and mutually supportive at both the measurement and modelling levels.

The work investigates the comparability of measurement datasets based on the eddy covariance method and the associated data processing practices across organisations. The work begins by examining carbon sequestration in four different measurement environments (a peat field, XX, and boreal forests in southern and northern Finland). An important objective is to assess how comparable the results obtained using different methods are.

In the next phase, satellite measurements and models based on satellite data will be analysed in the same measurement environments and compared with both measured and modelled datasets. This allows the consistency between satellite-based methods and eddy covariance results to be evaluated, as well as the agreement between modelling and measurements. The presentation and dissemination of results will be improved, for example through the Field Observatory platform.

At the end of the work package, a strategy and roadmap will be prepared to support the development of the national research infrastructure related to greenhouse gases. These will strengthen the long-term development of greenhouse gas measurements and the associated data infrastructure in Finland.