| dc.description.abstract | Clear-cutting is the most common method utilized in modern Fennoscandian forestry. As a large-scale disturbance, it completely transforms the forest ecosystem. It results in even aged monocultures which lack heterogeneity and critical biotic structures for forest dwelling organisms. In this study, we wished to investigate the long-term effects of clear-cutting on threatened bat species, as they are insufficiently examined in boreal forest ecosystems.
Ten sites across southeastern Norway were examined through acoustic monitoring and forest habitat measurements. Each site consisted of a pair of forest stands; one near-natural area (NN) which had never undergone clear-cutting, and one mature, previously clear-cut area (CC). The sites utilized are a part of the Ecoforest project (https://ecoforest.no/), which is a broader study of long-term ecological impacts of clear-cutting. The northern bat (Eptesicus nilssonii) was selected as the focal species in this study, due to its threatened status following a recent population decline and its distinction as the most common bat species in Norway.
Higher levels of bat activity in general were observed in the near-natural forest habitat. The northern bat displayed less commuting and foraging activity in the clear-cut sites, implying negative long-term effects of the logging technique. Northern bat activity was highest in high temperatures and low levels of precipitation, and the effects of weather conditions seemed dependent on forest type. Lighting conditions and forest composition such as dead wood volume had no significant effect on northern bat activity, though significant differences in forest composition between clear-cut and near-natural sites were found.
This study highlights the importance of researching the impact of forest management on a large time scale and how stand-replacing forestry negatively influences the activity of the northern bat in boreal forests. As the near-natural forest areas of Norway are continuously shrinking, the opportunity to research these habitat types and the effects of forest management are limited and urgent. | |
