Entwicklung der Libellenfauna einer Paludikultur-Versuchsfläche in den ersten drei Jahren nach ihrer Etablierung

Paludiculture refers to the use of wet and rewetted peatlands for agricultural and forestry purposes. There is a considerable need for research on the impact of these novel habitats for flora and fauna. Therefore, we investigated the importance of a paludiculture trial site (total size 0.4 ha; including four 10×10 m experimental ponds with different cultivation variants, which were studied in more detail) with common reed and cattail in the district of Oldenburg, Lower Saxony, as habitat for dragonflies and how its dragonfly fauna has developed in the first years (2022–2024) after its establishment. To determine the importance of the paludiculture at the landscape scale, we also conducted dragonfly surveys in several habitat types (ditch, canal, lake, pond, brook) in the surround-ing area in 2022 and 2024. Overall, we recorded 25 dragonfly species in the paludiculture, of which 20 (80%) were certainly or probably reproducing there in at least one of the years. The number of species increased slightly over time (15→18→17), while the number of certainly or probably reproducing species decreased slightly (14→13→12). Within the paludiculture, the experimental pond with the most constant water levels and the fewest periods of desiccation had the highest number of certainly reproducing species and the largest number of Anisoptera exuviae found in each year. The composition of the dragonfly fauna of the paludiculture changed considerably, especially from 2022 to 2023/2024: species of vegetation-poor waterbodies decreased sharply, while species of vegetation-rich waterbodies increased considerably. Of the total of 31 species detected within the whole landscape (paludiculture and reference habitats), 25 (81%) were also found within palu-diculture in at least one of the years. Eight of the 31 species (26%), including the ‘Red List species’ Ceriagrion tenellum, Ischnura pumilio, Lestes dryas, and Sympetrum danae, were exclusively found in paludiculture. Overall, the investigated paludiculture represented the most important dragonfly habitat with the most relevant species inventory from a nature conservation point of view during our survey period and therefore had an outstanding importance for the dragonfly fauna at habitat and landscape scale. The influence of regu-lar harvesting of the crops, the transferability of our results to commercial paludicultures and possible measures to promote dragonflies in these crops are discussed. Based on our results, we suggest ‘dragonfly plots’ as a measure to enhance the habitat quality for dra-gonflies, i.e., permanently water-bearing, sun-exposed open areas in commercial palu-dicultures where no reed or cattail is planted in order to create important reproduction habitats for dragonflies. However, there is still a considerable need for further research on these and other aspects.