Sod translocation to restore habitats of the myrmecophilous butterfly Phengaris (Maculinea) teleius on former agricultural fields

Abstract

In Europe, 50%–70% of former natural grassland area has been destroyed during the past 30 years due to land use changes, losses are expected to increase in the future. Restoration is thought to reverse this situation by creating suitable abiotic conditions. In this paper, we investigate the effects of sod translocation with specific vegetation to facilitate the restoration of a former intensive agricultural field into a wet meadow. First, starting conditions were optimized including modification of the local hydrology, removal of the fertilized topsoil, application of liming, and translocation of fresh clippings as a seed source. The second part aimed at restoring the habitat for the butterfly species Phengaris (Maculinea) teleius, one of the species that was especially affected by the loss of wet meadows. This species engages in a complex myrmecophilous relationship with one host plant, Sanguisorba officinalis, and one obligate host ant, Myrmica scabrinodis. We used sod translocation to create islands of habitat to promote host plant and host ant colonization. After 4 years following the restoration, we observed that plants spread from the transplanted sods to the surroundings. The vegetation composition and structure of the transplanted sods attracted colonization of Myrmica ants into the restored areas. Following the increase in vegetation cover and height, Myrmica ant colonies further spread into the restored areas. Therefore, sod translocations can be considered an effective restoration method following topsoil removal in the process of restoring wet meadows to provide a starting point for ant colonization and plant dispersion. With these findings, this paper contributes to the evidence-based restoration of wet meadows on former agricultural fields, including complex interactions between invertebrates and their required ecological relationships.