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.针对奥地利恩斯塔尔阿尔卑斯山区施蒂利亚州格绍伊泽国家公园（Gesäuse National Park）内的高山草原开展的动物区系调查，旨在揭示放牧行为对自然保护目标的影响。本研究于2004年植被生长季，采用陷阱诱捕器（pitfall traps）与G-Vac吸捕器（G-Vac suction sampler）采集了两类生物指示类群（bioindicator groups）：蜘蛛目（Araneae）与头喙亚目（Auchenorrhyncha）。共计记录标本9100号，隶属于82种表栖蜘蛛（epigeic spider）与53种叶蝉、飞虱物种。其中约20%的蜘蛛物种或多或少处于濒危状态，1种头喙亚目昆虫为奥地利新记录种；尤为值得关注的是，另有10种蜘蛛与4种头喙亚目昆虫为施蒂利亚州新记录种。基于G-Vac吸捕样本的种群密度数据显示：蜘蛛的种群密度范围为每平方米2至30只，叶蝉和飞虱的成虫密度范围为每平方米7至100只。本研究提出的自然保护管理措施包括：在选定草甸延续粗放型放牧模式，降低高强度放牧草甸的放牧密度，停止在敏感湿地生境开展放牧活动，以及进一步重视无植被覆盖的生境。