Clear-cut and substrate characteristics important for the occurrence of the beetle Upis ceramboides

Abstract: Disturbances, such as fire and wind, are important for saproxylic beetles (= beetles depending on decaying wood) to gain substrate in boreal forests. Clear-cutting is an example of a man-made disturbance. Measures such as prescribed burning have been made to resemble natural disturbances. The aim of this study was to see which clear-cut characteristics are important for the occurrence of the saproxylic beetle Upis ceramboides. This is a species favored by open habitats and is said to respond positively to forest fires. The distribution area in Sweden for this species has decreased during the last two centuries and I wanted to see if there were differences between clear-cuts in Hälsingland, where it is very rare and decreasing, and Norrbotten where this study was conducted. I found that a large area of dead birch wood had a positive effect on the occurrence per clear-cut. The larger area of dead wood in Norrbotten was the only parameter that could explain the higher frequence of occurrence of U. ceramboides in Norrbotten. Prescribed burning might have a positive influence on the occurrence of U. ceramboides if there is a high amount of substrate left, but further research should be made to investigate this. On substrate level, it is important that the substrate is sun exposed and decayed by white-rot fungi, preferably Fomes fomentarius. It also seems that the substrate should not be too wet since the beetle was found on logs with a low degree of contact with the ground. It is important to leave enough substrate, i.e. dead birch wood, after clear-cutting. This is done by leaving both dead and living birches, and if possible birches decayed by white-rot fungi.