Nature conservation evaluation of alpine pastures in the Gesäuse National Park (Styria, Austria) by means of the bioindicators spiders, leaf- and planthoppers (Arachnida: Araneae; Insecta: Auchenorrhyncha)

Faunistic investigations in alpine grasslands in the Styrian “Gesäuse National Park” (Ennstaler Alps, Austria) should show the effects of grazing for nature conservation aims. The two bioindicator groups Araneae and Auchenorrhyncha were collected by means of pitfall traps and a G-Vac suction sampler in the Vegetation period 2004: a total of 9,100 specimens were recorded, belonging to 82 epigeic spider and 53 leaf- and planthopper species. Twenty percent ofthe spider species are more or less endangered, one Auchenorrhyncha is new to Austria, and remarkably 10 spider- and 4 Auchenorrhyncha-species are new to Styria. The Densities (G-Vac Suction Samples) varied from 2 to 30 specimens per square metre in spiders and 7 to 100 adults in leaf and planthoppers. Suggested measures in nature conversation management include, among other things, a continuation of extensive grazing in selective meadows, the reduction of the densities in intensively grazed meadows, the cessation of grazing in sensitive wetland biotopes and the increased consideration of biotopes without plant cover.