National high-resolution conservation prioritisation of boreal forests

The continuous decline of forest biodiversity highlights the importance of the development of cost-effective and ecologically sustainable land-use planning approaches. Spatial conservation prioritisation (SCP) can be regarded as a useful tool for this challenge. We produced high-resolution, national scale SCP analyses to identify unprotected forest areas that host valuable forest biodiversity. We used stand-based modelled dead wood potential (DWP) data as a primary surrogate for conservation value. In addition, data on forestry operations that have negative impacts on biodiversity, connectivity between forest areas, the observations of red-listed forest species, connectivity to forest habitats of special importance for biodiversity, and connectivity to permanent protected areas were included in the analyses. Analyses addressed the estimation of present value and that of future potential following increases in connectivity. The results show that there are high conservation priority forest areas all over Finland although their distribution is highly fragmented. Depending on the version of the analyses, the best 10% of the landscape contains from 49% to 88% of the conservation values, a significant portion of which lie outside the current protected area network. Consequently, as biodiversity continues to decline in Finland and as most of the Finnish forest area is under commercial management, the current protected area network cannot be expected to halt the ongoing decline of forest biodiversity. Therefore, these analyses provide much-needed information for decision-making. They are a pragmatic tool for the planning of forest conservation networks and commercial management of forests at regional and national scales.