overarching problem
Various questions concerning grassland restoration are usually investigated in projects with a limited duration of 3 to a maximum of 5 years. Evaluation takes place at the end of this period – but are these relatively short timeframes sufficient for a sound assessment of this highly dynamic vegetation type? To answer this question, Dr. Silke Schaumberger, in her dissertation "Grassland restoration success – Comparison of initial and long-term evaluation," re-examined and evaluated two restoration projects at the HBLFA Raumberg-Gumpenstein 10 and 18 years after the initial setup, respectively. In both cases, the long-term results were compared with the initial evaluation, which proved to be very insightful. The results were published internationally.
Publication: “Successful transfer of species-rich grassland using green cuttings or threshed material: does the method make a difference in the long term?”
Based on the Central Europe project SALVERE (Semi-natural Grassland as a Source of Biodiversity Improvement, duration 2009-2011), a comparison between two different seed transfer methods for species-rich grassland was re-evaluated, and the results were published internationally. It was demonstrated that species-rich meadow seed can be transferred to different sites even in the long term, and that there are no significant differences between transfer via haymaking or green cutting. However, in the long term, undesirable species migrated into the new site, and the plant community adapted to the site conditions, which differed from those of the donor site. These developments were not yet apparent during the evaluation at the end of the official project period.
Publication “Long-term sustainable forest-pasture separations – a question of seed mixtures and management”
The second project, which was re-evaluated, involved a pasture established in 1998 on an acidic, montane site in the Eschwald forest near Mürzzuschlag as part of a forest grazing separation project. Repeated vegetation surveys showed that a single application of lime during establishment still resulted in significantly improved yield and vegetation parameters almost 20 years later. As expected, site-appropriate seed established itself better in the long term under the challenging site conditions than commercially available seed for more favorable locations; however, even here, undesirable species were able to establish themselves, especially without liming. The long-term deterioration of the overall plant population is attributable to the omission of any maintenance and management measures.
Conclusion
In summary, the dissertation underscores the great importance of long-term observations in grassland experiments, particularly in recultivated areas, as the dynamics and adaptability of the plant population often mean that reliable results are only obtained after extended observation periods. Even though long-term observations inevitably entail higher costs, they represent a significant contribution to research and can help us understand relationships in the future, the questions of which may not even be known today.
Dissertation by Dr. Silke Schaumberger
