Fragmented distribution of Isophya pienensis Maran, 1954 (Insecta, Orthoptera) in mountains: a result of permanent forest opening in highly forested landscape

Background and Purpose: Isophya pienensisMaran, 1954 (Orthoptera) is a stenotopic katydid occurring locally in Central and Eastern Europe. The purpose of the study was to document the habitat associations of I. pienensis in the Beskids in relation to historical land use and present landscape structure. Materials and Methods: Isophya pienensis was studied in the Moravian- Silesian Beskids Mountains at 15 sites representing small unforested areas surrounded by spruce forests on themassifs of the Smrk (1,276ma.s.l.) andKnehyne (1,256ma.s.l.)mountains. Thirty-minute timed counts were used. Results and Conclusions: Isophya pienensiswas found at 5 of the 15 sites but was not found at elevations below 1,000 m a.s.l. The occurrence of I.pienensis in the Beskids on small, isolated, shady sites at elevations over 1,000mis not a result of its being amountain species. Rather, it is due to the persistence of open-forest habitats and of ecotones near forest lodges where broadleaf vegetation is maintained on shady spots by occasional mowing. The permanent occurrence of I. pienensis probably depends on the presence of heterogeneous, early successional stages of forests and their ecotones, which were historically maintained by selective cutting, grazing, and charcoal production on a mosaic of grasslands