Lichens of wooden barns and Pinus sylvestris snags in Dalarna, Sweden

In Sweden, old wooden barns often host a diverse and threatened lichen flora including eight red-listed species, but this kind of barn has declined over the past 100 years. The barns have traditionally been made out of Pinus sylvestris, and it could be hypothesized that pine snags are the natural habitat for many lichens occurring on anthropogenic wood. We compared the lichen flora on old wooden barns in the village C of Gardsjo, Dalarna with that on snags of P. sylvestris. At alpha level, both species richness and lichen abundance were highest on snags, and for both substrates the north aspects had more species and higher abundance than E, S and W aspects. Overall species richness was similar on the substrates, with a slight tendency for higher gamma-level diversity on barns. NMS ordination showed clear compositional differences between barns and snags, and also indicated a more heterogeneous vegetation on barns. Implications for conservation measures are discussed.