2 and Table 2). There was agreement between years in that there was no difference for transplant survival and vitality between grouped and scattered retention trees. Also, the survival of autumn transplants was in both survey years significantly higher than the survival of spring transplants. However, transplant vitality differed significantly between survey years with autumn transplants being significantly more vital in clearcuts in 1996 but showing

no significant difference in 2008 (Table 2 and Table 3). The most important conclusion from our 14-year old transplantation experiment is that transplants of L. pulmonaria survived better on retained aspens on clearcuts than on forest trees, indicating that aspens left at clearcutting represent a suitable Nutlin3 habitat for this species. The positive effect of retention trees was especially high on northern sides of tree stems, and thus microhabitat conditions seem decisive for species survival. Also transplant Selleckchem Ferroptosis inhibitor vitality was higher on northern sides of tree stems, but this did not differ significantly between retention trees and forest trees, indicating that some factor seriously affects

transplant survival in the forests. One possible explanation might be gastropod grazing which has been increasingly noticed as an ecological driver of epiphytic population occurrences (e.g. Asplund et al., 2010). For L. pulmonaria, a positive correlation has been found between gastropod abundance and grazing damage ( Vatne et al., 2010), and snails in the boreal zone are known to be promoted by aspen since the litter of this tree species has a relatively high pH ( Karlin, 1961). It is likely that the grazing pressure is lower on clearcuts than in forests,

since many snails are sensitive to disturbance and microclimatic changes ( Hylander, 2011). The higher survival on retained trees is unexpected since L. pulmonaria is most common in old-growth forest ( Gärdenfors, 2010), i.e. the response of transplants does not match the actual occurrence pattern. However, large differences have been observed between potential and actual niches in lichen transplant Epothilone B (EPO906, Patupilone) studies. For instance, Sillett et al. (2000) found that transplants of L. pulmonaria were tolerant to open habitat conditions one year after transplantation, and Gauslaa et al. (2006) found L. pulmonaria transplants to have larger biomass growth in clearcuts than in old forests. Gauslaa et al. (2006) describe the long-term persistence of this species as a balance between light availability, where high levels benefit growth, and desiccation risk, since drought can drastically decrease populations. The relatively shady north side of retention trees is intermediate between the sun-exposed south sides of retention trees and the often very dark spots in old forests, and thus seems a favorable environment for L. pulmonaria.