The question therefore arises as to strategies for not only protecting extensive grassland areas with high floristic biodiversity in the intensively used agricultural landscape, but also for reintegrating them into our cultural landscape in order to create a (survival) basis for native insects and to halt the current collapse of biodiversity and the marked decline in the associated ecosystem services.
Project description
The REGRASS project investigated the contribution of newly established ecological compensation areas to promoting the biodiversity of beneficial organisms and ecosystem services in agricultural landscapes over a three-year period. The HBLFA Raumberg-Gumpenstein, as a project partner, was responsible for establishing suitable strips of extensively managed grassland. To this end, in late summer 2016, flower-rich meadows in the form of grassland strips were established on five experimental plots within cultivated fields and managed twice daily by contract farmers. The project partners from the University of Natural Resources and Life Sciences, Vienna (BOKU) and the University of Vienna investigated the diversity and abundance of spiders, ground beetles, and ants, which make important contributions to pest control, as well as important pollinators such as wild bees, honeybees, bumblebees, and hoverflies. Additionally, animal numbers were compared between the new and existing meadows and so-called biodiversity areas (areas subsidized under the Austrian Agri-Environmental Programme - ÖPUL). The results obtained provide information about the initial colonization rate and thus about the effectiveness of newly created meadows as ecological compensation areas and are part of the final report of the corresponding FWF project, which will be published in early 2021.
Results
In summary, the results from 2017 to 2019 show that pollinating insects very quickly accepted the newly established meadows as a foraging habitat and migrated into them from the surrounding landscape. In some cases, very high numbers of individuals and species were observed in the newly established meadows. Among the predatory insects, spiders, starting from very high individual numbers in the newly established meadows, showed significantly higher densities in cereal fields near the new meadows than in cereal fields far from the new meadows. This indicates a beneficial insect promotion effect in the cereal crops, originating from the new meadows.
With proper seedbed preparation and the use of appropriate establishment techniques, it is possible to establish species-rich, extensive grassland stands even on nutrient-rich, formerly intensively used areas. For the ecological value of a seed mixture used for this purpose, it is essential that it meets the relevant criteria regarding species selection and the regional origin of the species used. A high-quality certification system is necessary to guarantee compliance with all requirements. In the accompanying faunal studies of these flowering areas, compared to existing extensive meadows, agri-environmentally supported flowering areas, and adjacent arable land, these mixtures demonstrated their significantly higher attractiveness to wild bees, bumblebees, and hoverflies (publication currently in preparation). In the completed project, HBLFA Raumberg-Gumpenstein was commissioned to compile a suitable seed mixture of regional wild plants, to implement the technical establishment of the seed, and to develop a maintenance concept. Subsequently, the development of the plant population in the newly created meadows was observed and examined with regard to projective cover, species composition, flowering times, as well as forage yield and quality.
Final report
Team
Dr. Wilhelm Graiss
Head of Department