Master's Defensio


Johannes Buchner BSc

Analysis of the aquatic and semiaquatic Coleoptera and Heteroptera in the Naturschutzgebiet "Hörbranzer Schmelzwiese" (Vorarlberg).

Advisor: Harald Krenn

Master's Defensio - Friday, June 18th 2021, 13:00


In the current study the composition of the species communities of aquatic and semiaquatic Coleoptera and Heteroptera was investigated. The study area was the “Hörbranzer Schmelzwiese”, which belongs to the Natura 2000 site “Leiblach” in Vorarlberg (Austria). Seven different water bodies were sampled eight times during the vegetation period 2020. For sampling a combination of different trapping techniques was used. In this way a total of 4679 adult insects from 58 different species could be found.

The results show that there were significant differences between the sampling locations. The dammed Mühlbach turned out to be poor in species and individuals, the floodplain forest showed the highest diversity in terms of index-values (Gini–Simpson and Shannon–Wiener) and sites that were not permanently water-bearing showed the highest abundances. The large sedge swamp was the location with the most species and individuals. The most frequently recorded species were Graphoderus cinereus, Hydaticus seminiger and Hydrochara caraboides.

Furthermore, the species Hydroporus rufifrons and Laccophilus poecilus, which are classified as critically endangered on the Red List of aquatic beetles of Bavaria, could be documented. The species Acilius canaliculatus was recorded for the first time in Vorarlberg. The FFH species Graphoderus bilineatus could not be recorded at any of the sites in contrast to previous investigations. Furthermore, the FFH species northern crested newt (Triturus cristatus) could be found. In general, this study can be helpful for future conservation efforts and expands the knowledge about the aquatic and semiaquatic coleopteran and heteropteran communities in Vorarlberg.




© Josef Buchner
© Josef Buchner
© Josef Buchner