Die epigäische Spinnenzönose (Araneae) auf Schotterbänken der Mittelgebirgsbäche und -flüsse im Rheinischen Schiefergebirge
Spider community (Araneae) of gravel bars along streams in lower mountainous areas (Rheinisches Schiefergrbirge, Northern Hesse, Germany)
The spider communities on gravel bars along streams in lower montainous areas of Northern Hess were investigated. Eight streams differently altered by human impact were studied: four small streams without weirs and impoundments, two regulated small streams and two larger regulated streams. The sampling sites were located in one kilometer streches of the upper, middle and lower reach of each small stream, respectively. In addition the gravel bars in several floodplain sections of larger streams were investigated. Altogether 592 quantitative samples of spiders were made. 7027 spiders (Araneae) comprising 77 species were encountered. Only two species (Oedothorax agrestis, Pirata knorri) make up more than 70 percent of all spiders captured. Erigone atra and Erigone dentipalpis were frequently foung along all streams investigated. While Diplocephalus permixtus and Diplocephalus protuberans were only encountered along the small streams, Oedothorax retusus and Pardosa amentata were predominantly recorded on gravelbars of large streams. Diplocephalus protuberans was recorded for the first time in Hesse. The mean abundances (median) ranged between 4 and 28 individuals/m2. 198 individuals/m2 have been the maximum of abundance.
Araneae; gravel bar; small streams; Hesse; Germany