Testing the accuracy of Forest Monitor. Can this map tool accurately differentiate between forests with high and low natural value?

Abstract

Large parts of Sweden’s forests have been cut down or otherwise altered, contributing to declines in several forest-dependent species. It is therefore important to identify and protect old and rare habitats and species of conservation concern. However, identifying these areas and species can be challenging. Forest Monitor (Skogsmonitor) is a map-based tool that highlights forest areas likely to hold conservation values. This study assesses whether Forest Monitor’s classifications correspond to field-based natural-value assessments. If the results are statistically significant could this contribute to the discovery of previously unknown valuable areas. 20 randomly selected locations were surveyed using the standardized method Naturvärdesinventering (NVI). The sampling sites within each location were divided into two groups. One that Forest Monitor classified as having conservation value and one that it did not. The two groups were compared to see if their natural values according to NVI were statistically different from each other. Preliminary findings indicate differences between the two groups, suggesting that areas highlighted by the tool tend to receive higher NVI classes. However, several discrepancies were also observed, including both false positives and false negatives. The tool appears useful as an early screening instrument. However, field inventories remain essential for site-level evaluation.