Dead branches on living trees constitute a large part of the dead wood in managed boreal forests, but are not important for wood-dependent lichens

Questions How much dead wood in the form of dead branches attached to living trees, compared to other types of dead wood, is present in managed boreal forests? Which lichen species grow on this substrate? Location Two areas of managed coniferous forest in southern Sweden. Methods We surveyed the numbers and surface areas of attached dead branches and all other major types of dead wood in 80 stands of managed coniferous forests of various ages and wooded mires. In total, we recorded 5546 dead branches attached to 480 living trees. We also recorded the species of lichens growing on 812 of these dead branches. Results The surface area of attached dead branches was generally of the same magnitude as that of all other wood types combined. Of the 46 lichen species identified growing on dead branches, 42 were generalist species characteristic of conifer bark and four were wood-dependent specialists. We found no significant difference in lichen species composition between dead branches of Picea abies and Pinus sylvestris, and only small differences in species composition between different stand types and between study areas. There were no clear differences in species composition between the study areas. Conclusions Although overlooked, attached dead branches constitute a significant proportion of all dead wood available in boreal forests. However, the lichen communities on these branches mainly consist of generalist species. Lichens on attached dead branches thus do not seem to contribute strongly to the species pool of wood-dependent lichens in managed boreal forests.