This paper deals with the species composition of epiphytic lichens in Central European oak forests. A total of 192 oak trees at 48 localities in the Czech Republic, Slovakia and Hungary were investigated. In total, 104 lichen species were recorded and divided into three groups in accordance with their frequency of occurrence on trees within the area. The importance of abiotic factors affecting species composition was assessed by multivariate statistics. Principal component analysis illustrated that lichen assemblages reflected geographical distribution of localities and that the occurrence of many species is closely associated with several environmental factors. In particular there is a high negative association with pollution, and positive associations with precipitation, solar radiation and basic bedrock. The variation partitioning estimated the influence of environmental parameters, human impact and naturality factors on lichen composition. Cluster analysis recognized six communities of lichens, of which the members differed from those in the other communities in their autecological characteristics. Two of the communities can be assigned to Parmelion caperatae and Pertusarion amarae and seem to be similar to natural lichen communities of oak forests in Central Europe. Possible reasons for absence of several epiphytic lichen associations (Lobarion pulmonariae, Pertusarion hemisphaericae) in the forests studied is discussed and the species composition in Central Europe was compared with the lichen assemblages in oak forests in neighbouring regions (western Europe, Scandinavia). On the basis of these findings several indicative species of close to natural oak forest are suggested (Acrocordia gemmata, Bacidia rubella, Calicium spp., Caloplaca lucifuga, Cetrelia olivetorum s.l., Chrysothrix candelaris, Flavoparmelia caperata, Melanelia subargentifera).
Morphometric skull variation was studied in Rhinolophus mehelyi, R. euryale and R. blasii by means of 50 cranial, mandibular and dental measurements. In R. euryale differences between age groups (subadults, adults and old adults) were not significant. Poorly pronounced sexual dimorphism (male skulls were, on average, larger than those of females in some measurements) and low geographical variability within Bulgaria were observed in R. euryale. We propose a simple biplot (length of cheek teeth against the rostral posterior width), a stepwise discriminant analyses of some criteria and numerical keys that allow the clear determination of crania or their parts. A large additional sample of incomplete crania was determined on the basis of these keys which, in turn, allow data to be obtained on species distribution patterns. Rhinolophus euryale is the most frequent and probably the most abundant horseshoe bat species examined, and occurs throughout Bulgaria. Rhinolophus mehelyi is widespread but appears to be relatively rare. Rhinolophus blasii is confined mainly to the southern regions of Bulgaria, but may be abundant locally.