A population genomic study of the effect of clear-cut forestry on the beetle Gyrophaena boleti

The boreal forest is the home to several thousands of species, and about 2/3 of the forests are under management, mostly for timber production. In Norway only two percent of the forests are natural, and only 21% of this area is protected. The main logging strategy in Norway is clear-cutting followed by planting, altering the composition of both living trees and dead wood. Clear-cut forests are in particular danger of losing biodiversity. Gyrophaena boleti is a small rove beetle inhabiting bracket fungi in these forests, living in both mature previously clear-cut and near-natural forests. How the different management strategies are affecting the genetic diversity of this beetle is currently unknown. Utilizing pooled whole genome sequencing to do a population genomic study of G. boleti from nine paired forest sites, we show that G. boleti in the clear-cut forests tend to have slightly lower genetic diversity than G. boleti from near-natural forests. Although generally the genetic diversity is high. We also found little genome-wide population structure between sites with paired forest stands. However, we found peaks of differentiation between populations in different forest sites and stands which could be genomic regions involved in local adaptation. This is the first genomic study of the species G. boleti, contributing to the knowledge of how small, specialized insect species are affected by habitat change. This understanding could help support the development of conservation strategies and management practices of the boreal forests.