B. Papp szerk.: Studia Botanica Hungarica 29. 1998 (Budapest, 1999)

Erzberger, Peter: Distribution of Dicranum viride and Dicranum tauricum in Hungary

representing post-1950 herbarium material. One entry seems to correspond to the Göcsej region, while the other is roughly situated at the Nógrád basin, halfway between the Börzsöny and the Mátra Mts, and thus cannot be allocated to any of the specimens revised in this paper. From the point of view of protection, only the records in the Bükk Mts and in the Nyírség are within protected areas of higher rank (Bükk National Park and Bátorliget Nature Reserves, respectively), whereas the other records come from less well-protected regions. But even in the Bükk National Park, where the greatest number of the localities of D. viride is situated, operations of forestry management could represent a considerable threat. This species is reported to require old trees (especially beech) in an undisturbed woodland environment with an even and high humidity (MARTTNY and HALLINGBÄCK 1995). However, recently D. viride was found in 2 places in the Bükk Mts growing on the bark of Quercus species in rather open woodland at mountain ridges in southern exposition. The remarkable fact that D. viride, a species of subcontinental-montane distribution (MARTINY and HALLINGBÄCK 1995), occurs at an altitude of only 130 m a.s.l. in the Great Hungarian Plain (at Bátorliget), has already been commented on elsewhere (STANDOVÁR et ai. 1991). The existence of D. viride in this locality could be verified recently (JAKAB 1997b). For most other records from 1968 or earlier, an actual verification would be highly desirable. D. tauricum, on the other hand, is one of the few moss species that have been reported to extend their range within the last decades {e.g. HEGEWALD 1969, SMITH 1978, DULL 1980, KLAWITTER 1984, DULL and MEINUNGER 1989, with distribution map, BUTTERFASS 1992, FRAHM and FREY 1992, FREY et al. 1995). For Hungary, MARSTALLER (1994, 1995) seems to be the first to have published results suggesting an increase of frequency. His detailed distribution map for the Budapest region (Pilis and Buda Mts) shows 14 entries. Marstaller'

s suspicion that the D. viride record for the Buda Mts in BOROS and VAJDA (1952) corresponds in fact to D. tauricum, is confirmed in the present paper. MARSTALLER (1994, 1995) found the most extensive stands of D. tauricum in disturbed habitats, especially around abandoned quarries (Ezüstkevély near Pilisborosjenő, Pribarinye northeast of Pilisszántó). This, he argues, is suggestive of a strong extension of range within the past decades. He also discusses the bryosociological affinities of this moss (MARSTALLER 1983, 1994, 1995). The data of this paper also support the assumption that D. tauricum is at present in a phase of rapid increase. It is very unlikely that this species was simply overlooked by generations of former Hungarian bryologists, especially in areas as well researched as the Pilis-Buda Mts. Future detailed bryofloristical mapping could probably document this dynamic development in more detail. The causes for the extension of range observed in many European countries are still far from clear. One hypothesis states that in and around industrial regions