Forest resource information is collected using a remote sensing method that utilizes sample plot measurements, laser scanning and aerial photography. The new inventory round, which started in 2020, is proceeding in accordance with the National Laser Scanning and Aerial Photography Programme. The laser scanning cycle is six years and new forest resource information is produced accordingly. Aerial photographs are taken every three years, that is, in the same year as the laser scan, and for the second time in the middle of the scanning cycle.
Forest resource information is updated based on information from various data sources
Forest resource information is constantly updated between inventories from different data sources and tree stands are grown annually with growth models. As a result, up-to-date and accurate forest resource information is available regardless of the time of the inventory.
The updates take into account forest growth, the impact of forest management and felling on the amount of forest, as well as changes in property boundaries and forest use. The updates primarily complement the characteristics of forest compartments, such as the number of tree stands. The boundaries of the compartments are updated when their changes are included in the available update information and can be determined with sufficient accuracy based on the data source used.
In 2022, a new information system will be introduced, which will be used to also update forest resource information in the form of grids with growth models and transfer the information on the updated compartments to the corresponding grid boxes.
Important data sources in updating forest and nature information are:
- forest use notifications and Kemera information
- harvester information
- information on the implementation of forest regeneration and forest management work
- update requests in the Metsään.fi service
- changes in property boundaries
- environmental support and nature conservation materials
- aerial and satellite photography.
The accuracy of the information used in the process of updating contributes to the quality of forest resource information. For example, a forest use notification is an intention to take a planned action, for example, felling, within the next three years. However, the Finnish Forest Centre will not receive information about the implementation of the action. In the new system, forest information will not be updated based on a forest use notification alone, unless another data source, such as a more recent aerial photograph, can ensure the implementation of the felling.
Up-to-date information from harvesters and loggers
The aim of the update is to increasingly utilize information from harvesters and information on the implementation of forest management work. Obtaining this information for updating forest resource information requires cooperation in the forest sector, from which all users of the information benefit. The Finnish Forest Centre has at its disposal the time of the felling, the felling method and the delimitation of the felling compartment formed from the GPS points of the felling machine. Accumulated felling information is not forwarded to the Finnish Forest Centre.
If the felling method is thinning, the tree stand is thinned using thinning models in accordance with the forest management recommendations. This does not produce absolutely correct information about the remaining trees, but the key is that the thinning is updated, and the corresponding information is available as soon as possible, for example, for wood procurement planning. It is likely that after the thinning, a new laser scan will be carried out and more detailed forest information on the tree stand will be available before further felling is planned for the compartment.
Implementation information of forest management work refers to the so-called self-monitoring information collected by the logger, for example, on tending of seedling stands. This information is also to be used for updating forest resource information.
Forest owners can influence the timeliness of their forest data
Updating forest and nature information is an ongoing work that sets target times for updates based on different data sources. The updating of forest resource information does not involve separate field work trips. Habitats of special importance in accordance with section 10 of the Forest Act are always confirmed in the terrain.
Forest owners can easily influence the timeliness of their forest data. If maintenance work or felling has been carried out at a forest property, the work can be reported as done in the Metsään.fi service. The Finnish Forest Centre will update the information on the forest compartments within two weeks.