Abstract
Open habitats are disappearing from European forests. This is mainly due to various management-related practices, such as afforestation and the maintenance of closed canopy plantation forests. Open forests are also declining as a result of the abandonment of traditional forest use practices and natural succession. The effects of the establishment and maintenance of power lines as highly artificial but open habitats in forests on native insect biodiversity remain relatively poorly investigated. We investigated differences in biodiversity between forests and open habitats under power lines in Poland. Namely, we focused on nine insect taxa using the most suitable methods for data collection, i.e., observation and trapping. The studied habitats were forests used for timber production dominated by Scots pine, which is the most commercially important tree species in Poland. In total, we recorded the presence of more than 400 insect species. We found that butterflies as well as ground beetles were significantly more biodiverse under the power lines compared with the forest interior. Furthermore, jewel beetles, long-horned beetles, weevils and bark beetles, rove beetles and darkling beetles appeared to be more species rich under the power lines, click beetles were indifferent, and only lady-bird beetles appeared to be more abundant in forests. Additionally, ground beetles with a strict affinity for forests were surprisingly not negatively affected by power lines. We highlighted the importance of forest-free areas under power lines for the improvement of native forest biodiversity. Artificial and relatively intensive management activities related to the distribution of electric energy play important roles in creating novel or alternative habitats for many insects. Our paper contributes much to the knowledge about the importance of artificial open areas for the diversity of insects.