What is the potential to increase local biodiversity in semi-urban amenity grasslands through meadow constructions?

The loss of biodiversity worldwide and methods of prevention are hot subjects receiving increased interest in todays’ research. Meadow construction in urban areas has been the focus of recent studies to increase both local and global biodiversity. In my report, I address potential analyses to conduct in advance before practical meadow constructions in a landscape. The subject I chose to focus on for this report was a LONA-project aimed to construct meadows on contemporary amenity grasslands in a semi-urban municipality. I used vegetation data from an inventory executed in 2021. Patches were in advance classified based on conditions observed during the inventory with class 1 obtaining the highest meadow potential, class 2 obtaining mediocre potential, and class 3 weak or no potential. I analysed vegetation data on species richness, environmental indicator values, and composition. Additionally, I analysed the soil types and historical land uses in the study area to display credible soil characteristics. The order of Lepidoptera was used as a model taxon for pollinators and the red-listed Marsh fritillary (Euphydryas aurinia) was separately analysed for conservational purposes. To illustrate the landscapes’ ability to facilitate the dispersal of butterflies, connectivity analyses of varying meadow construction scenarios were executed. Results indicate higher species richness on average per patch and more indicator species in class 1, suggesting a better starting point and making quality assessments more credible in comparison to class 2. Underlaying soil type seems to some extent to influence the meadow potential by affecting vegetation composition and hence butterfly occurrence in terms of host plant distribution. I could however not draw any conclusions from the effect of historical land use on current patch classifications, and consequently meadow potential. To facilitate for E. aurinia to widen its distribution in the study area, and to avoid local extinction, further conservational efforts should focus on mimicking the conditions and current management of the powerline corridor, that currently yields high diversity of butterflies and abundance of E. aurinia, to other powerline corridors in the study area. To facilitate dispersal of butterflies and other pollinators, target meadow areas of both class 1 and class 2 patches should be constructed to avoid patch isolation, as illustrated in the connectivity analyses. Further research is needed to investigate other factors possibly affecting suitability of grasslands for meadow construction.