A comparative study of larval Odonata data within permanent ponds across Hungary

Whilst being small and shallow, permanent ponds provide valuable habitats for a multitude of organisms as well as provide habitats for animals like aquatic insects and others, including many rare species. These ponds, which were often neglected in limnological studies, were the core of our joint project, the 3rd freshwater project - EUROPONDS in order to evaluate the often overlooked ecological ecosystem services provided by permanent ponds across Europe. As a part of this project, two Hungarian ponds were surveyed for a full year (2020/21). One of the project aims was to assess the freshwater macroinvertebrate assemblages by dip netting over the four annual seasons. Here, we present preliminary results examining the data on larval Odonata of two Hungarian ponds in relation to the physicochemical variables measured, as well as compare the results to a previous national survey. Altogether the examination of 24 waterbodies (22 from a national survey and two from the EUROPONDS project) was carried out in this study. All of the involved water bodies were clustered using a Ward analysis including the water physicochemical parameters into three groups, and then the dragonfly fauna was investigated within the groups found. Diversity metrics and the presence or absence of different species were also included and the results were compared between the different clusters. Herein, we aimed to assess differences between the three main clusters, identify key factors driving the presence of the studied species and the relationship between the diversity indexes and the physicochemical parameters influencing the Odonata communities in the studied ponds.