University of Zagreb. Faculty of Science. Department of Biology.
Abstract
Trčci (Coleoptera, Carabidae) su istraživani duž šumsko-livadnog ekotona, te oštrog i sukcesijskog šumskog ruba dinarske bukovo-jelove šume (as. Omphalodo-Fagetum) i susjednih otvorenih staništa na području Gorskog Kotara. Dodatna istraživanja provedena su i na području prašume Čorkova uvala (NP Plitvička jezera). Trčci su sakupljani metodom lovnih posuda od travnja do studenog 2009. godine. Ukupno su sakupljene 31 574 jedinke svrstane u 89 vrsta trčaka. Bogatstvo vrsta i raznolikost trčaka na ekotonu nisu značajno viši na području ekotona u odnosu na susjedna staništa, što nije u skladu s klasičnom hipotezom ekotona. Nasuprot tome, raznolikost je bila viša na oštrom i sukcesijskom rubu. Zajednica trčaka u ekotonu sličnija je zajednici trčaka unutrašnjosti šume nego li livade, a slične rezultate pokazuju i istraživanja na šumskim rubovima. Trčci nisu izbjegavali zonu ekotona i šumskih rubova, ali isključivi rubni specijalisti nisu zabilježeni, već su detektirane vrste koje pokazuju pozitivan odgovor prema ekotonu i rubu. Ekoton uklopljenog šumskog ruba predstavlja barijeru za većinu vrsta otvorenih staništa, dok je za pojedine šumske vrste filter koji uspješno prolaze. Temperatura tla, vlaga tla i otvorenost sklopa su značajno utjecali na sastav i strukturu trčaka na ekotonu i šumskim rubovima. Broj vrsta i brojnost jedinki trčaka su značajno veći u gospodarenoj šumi, nego li u prašumi, a fauna trčaka obje šume pokazuje visok stupanj sličnosti.Carabid beetles (Coleoptera, Carabidae) were studied across a forest-meadow ecotones and at abrupt and gradual forest edges of Dinaric beech-fir forests (as. Omphalodo-Fagetum) in the Gorski Kotar. Additional research was conducted in the virgin forest Čorkova uvala (NP Plitvice Lakes). Beetles were collected by pitfall traps from April to November 2009. A total of 31 574 individuals belonging to 89 species were collected. Carabid species richness and diversity were not significantly higher in ecotones compared to adjacent habitats, which is not in accordance with the classical ecotone hypothesis. However, diversity was considerably higher at the abrupt and gradual forest edges than in the forest interior. Carabid assemblages in the ecotones and forest edges were more similar to assemblages in the forest interior than to assemblages in the meadows. Carabids did not avoid ecotones and forest edges, but no strict edge specialists were found. However, positive responses of carabid species towards the ecotones and forest edges were observed. Embedded forest edges acted as barriers for most of open habitat species, while for some forest species they acted as filters. Soil temperature and humidity, and canopy openness significantly affected the carabid beetle assemblages in the ecotones and forest edges. Carabid species richness and activity density were significantly higher in managed forests, than in the virgin forest, though the carabid assemblages of both forests showed a high degree of similarity
