The distribution of corticolous lichens on Danish angiosperm trees

In the forest ecosystem, the diversity and the distribution of corticolous lichens depend on several factors. One of these factors is tree species. The variation in the surface structure, chemical composition and pH of the bark creates different habitats for lichens communities. Furthermore, age related changes in bark properties along the tree stem create a gradient of habitats ranging from the older bark at the stem base to the newly formed bark at the top of the tree. Research on corticolous lichens has mainly focused on the lower and accessible part of the tree stem. The aim of this study is to examine the distribution of corticolous lichen species along the whole tree stem of seven Danish angiosperm tree species growing in Common Garden plantations established in 1973. Altogether, 24 trees of each tree species were felled in March 2015. Wood discs were cut out at regulated heights along the main stem of the trees and the bark on each wood disc examined for the presence or absence of lichens. Initial results show that some corticolous lichens prefer to grow on certain tree species and within certain height intervals along the tree stem. Further, the results show a difference in distribution and diversity of lichen species among the tree species. Identification of the distribution patterns according to height and tree species will be beneficial for future research on analyzing the influence of bark texture, pH, chemical composition and microclimatic conditions within tree and among tree species.