Yves P. Klinger, Research assistant at the Division of Landscape Ecology and Landscape Planning Justus Liebig University Giessen, Germany
Green hay transfer is a common method for restoring grassland biodiversity which is also used in floodplain meadows. The method is considered effective and affordable, but limited to regions with species-rich donor sites and can be organizationally complex. Despite many practical guides on grassland restoration and a body of studies investigating factors driving restoration success, many projects struggle to meet their goals. The exact reasons for project success and failure often remain unknown, and scientific literature on the success of green hay transfer often omits important aspects.
The knowledge of practitioners working in restoration projects is an under investigated resource of knowledge that can help to make restoration more successful. It is, however, scattered across many projects and regions, with limited exchange between practitioners. To consolidate this knowledge, we conducted a qualitative study to identify key success factors in green hay transfer from practitioners’ perspectives (Sommer et al. 2023).
We conducted 31 interviews with practitioners from administration, landscape planning, and agriculture in six federal states of Germany and Luxembourg. The interviewees had all been involved in restoration projects with green hay transfer, using either fresh or dry material, including methods specific to dry grasslands. During the interviews, we raised key topics mentioned in the literature, covering the selection of methods, practical implementation, long-term maintenance, and monitoring success (for a full list, see Sommer et al. 2023). Further, our partners were invited to add their own insights concerning topics relevant to them. The interviews were transcribed and analyzed using qualitative content analysis, with 17 categories emerging through iterative coding (Sommer et al. 2023). Our main findings are summarized here.
Match donor and recipient sites and check for problematic species
Selecting donor and recipient areas is often the first challenging step. Donor sites need a high density of target species, while recipient sites should have similar conditions to ensure successful species establishment.
Prepare recipient sites and make sure you have the right machinery for the job
Soil and site preparation may be necessary to reduce competition and give the species to be introduced a good start. Our partners recommended thorough soil preparation on recipient sites, using methods like plowing or tilling to minimize competition and prepare the seedbed. In some occasions, legal authorization has to be obtained. Further, the regional availability of machinery and personnel should be planned in advance to manage costs and consider logistical challenges.
Choose the right harvest timing and promote species establishment
Choosing the right phenological time to harvest maximizes seed maturity for a wide range of target species. Multiple harvests or hand sowing can improve the number of species to be transferred. Fresh plant material was preferred over hay, as storing hay usually leads to seed loss. Short transportation distances help preserve seed viability, as heating during transit can damage seeds. In the first years after the material has been transferred, cutting back competitive species, can be crucial to promote establishment. It is also important to set realistic expectations for everyone involved, as establishing a flower-rich community can take time.
Plan for long-term management and monitoring
Long-term success depends on continued management and monitoring. This should be planned early, with funding secured through agricultural use or other schemes. Setting up permanent observation plots and performing regular inspections can be essential to track species establishment and guide future interventions.
Collaboration and knowledge-sharing are crucial for green hay transfer
According to our partners, successful projects rely on good coordination of the project at hand and respectful communication between participants. Thus, appointing a project manager and involving stakeholders early in the project is critical. Building sustainable regional networks was viewed as essential and involving experienced practitioners in new projects helps to avoid common pitfalls.
Conclusion
In addition to technical expertise, the success of grassland restoration relies on strong regional networks. Collaboration between conservation, agriculture, and local authorities is key to addressing future restoration challenges. Research can play a vital role in facilitating knowledge exchange and counselling project partners.
We are grateful to the practitioners that shared their experiences and insights with us. The original study can be found here: Sommer, L., Castro Campos, B., Harvolk-Schöning, S., Donath, T. W., Kleinebecker, T., & Klinger, Y. P. (2023). Grassland restoration with plant material transfer – bridging the knowledge gap between science and practice. Global Ecology and Conservation, 47, e02638.
