Assessing conservation values of forest stands based on specialised lichens and birds

摘要

We compared the presence of sets of epiphytic macrolichens and resident birds as indicators of old and deciduous trees in each of three forest types in south central Sweden: mixed/deciduous (MIX), old coniferous (OLD) and managed (MAN). Lichen diversity and abundance was greatest in MIX but the mean number of species per stand was highest in OLD. The number of species per stand increased with the proportion of old trees in the stand. The diversity and mean number of resident bird species was highest in MIX while OLD and MAN did not differ. The number of bird species and the proportion of deciduous trees per stand were positively correlated. Thus the conservation of stands of old trees that also contain deciduous (non-commercial) trees will favour both lichens and birds and probably a wide range of other plants and animals. The study shows that the present Swedish use of only the floristic component for assessment of conservation values is not sufficient. Adding area-demanding specialists such as certain resident birds is a step forward towards a reliable indicator system.