Abstract (eng)
Worldwide, there is an observed decline in insect biomass. This decline also impacts the biodiversity of butterflies in Europe. Due to their sensitivity to environmental changes and direct human interventions, butterflies are considered indicators of biodiversity and climate change. As a result, monitoring efforts, in the form of Citizen Science projects, have emerged and been conducted in recent years. These initiatives aim to contribute to the collection of data over an extended period. The data collected can be utilized to make more precise assessments of butterfly populations. The goal is to generate supplementary data. This master's thesis is made in collaboration with WWF in 2023, butterflies in the Marchegg floodplain reserve were identified and counted. A transect was established along the flood protection dam. The green areas of this dam are partly mowed by humans and partly grazed by horses. The transect was walked ten times between June and September 2023. The objective was to identify the influences of mowing and grazing on butterflies and to discuss the advantages and disadvantages of the applied monitoring methods. In total, 1088 butterflies from 25 different species were recorded. The most frequently observed species, listed in descending order, were Maniola jurtina, Pieris rapae, Coenonympha pamphilus, Polyommatus icarus, and Melangaria galathea. A comparative analysis between the mowed and grazed areas revealed no significant differences. Only in two instances there was an immediate negative effect of mowing on butterfly occurrence observed. Based on these results, a mowing concept is developed in this work, aiming to mitigate the direct impact of mowing. The collected data and the described processes of this study are intended to serve as a foundation for establishing a butterfly monitoring program in the Marchegg floodplain reserve in the future. Additionally, they are intended to motivate further individuals to participate in Citizen Science projects.