When forests grow on unfavorable soils for the tree species, the risk of poorer vitality increases, with more forest damage such as wind, fungi, insects and sometimes fire as a result. With the drought and bark beetle attacks of recent years, Swedish spruce forests have been very vulnerable and there is a need to identify forests growing on unfavorable soils using various tools.
New method to identify forests at high risk of damage
On behalf of Länsförsäkringar, Metria and Skogsforsk have developed a method for identifying and mapping forests at high risk of forest damage caused by, for example, incorrect choice of tree species based on the location*. The method, which can be applied over large parts of Sweden's forest land, is based on nationally available geodata.
Three areas in Blekinge, Närke and Jämtland have been used to evaluate and test the methods. The mapping shows where forests grow on unsuitable sites with a minimum mapping unit of one hectare, which can also be summarized by property per tree species. The tests show that spruce forest on dry land and spruce forest on coarse sediments and moraines can be mapped and identified. Pine forests on clay-rich soils should also be identifiable even if they occur sparingly.
Increased knowledge leads to risk awareness
With increased knowledge about the extent of how much forest grows on the 'wrong site', forest owners can become more risk aware, but also manage the forest in a way that reduces the risks of forest damage.
- By better understanding and obtaining information about the site conditions where our forest grows, we can pave the way for less vulnerable and more profitable forestry, says Gustav Arctaedius, Metria, who participated in the project as a GIS expert.
The project has been carried out during 2020-2021 and is financed by Länsförsäkringar's research fund.
Read more about the project
Read the report (Länsförsäkringar)
Read more about the study (Skogforsk)
* Stand location
A stand is a forest site with uniform conditions regarding climate, soil and other plants and animals. Stand characteristics mean things that describe vegetation types, soil type and soil moisture, including access to moving soil water.