MICROHABITAT ANALYSIS OF 3 FEN-GRASSLAND GRASSHOPPER SPECIES (ACRIDIDAE, GOMPHOCERINAE)

Based on an individual data recording of 13 biotic and abiotic microha bitat variables, the microhabitat of 3 sympatric and coexisting fen-gr assland grasshoppers was analyzed. The investigated species were close ly related Chorthippus albomarginatus Degeer 1773, Chorthippus montanu s Charpentier 1825, and Chorthippus parallelus Zetterstedt 1821 (Acrid idae: Gomphocerinae). The application of Principal Components Analysis combined 70.4% of the recorded data to 3 main factors: (a) Perch heig ht in the vegetation and its density, (b) leaf canopy, and (c) microcl imate, describing the microhabitat of the 3 species in a sufficient wa y. Supported by 3 ecological standard calculations, the results show a finely tuned microhabitat utilization, confirming a strategy of compe tition avoidance of the 3 species in case of coexistence. Even on micr ohabitat scale Ch montanus is stenoecious, whereas Ch albomarginatus a nd Ch parallelus are euryecious. Thus, the species' macrohabitat requi rements are continued in the microhabitat.