Restoration of lowland meadows in Austria: A comparison of five techniques

European environmental policy mandates that biodiversity loss should be halted through restoration. However, knowledge about the efficacy of different restoration treatments for lowland meadows is still incomplete. Our study monitored two restoration projects in South-East Austria that served as compensation measures for the loss of species-rich grassland. We compared the efficacy of five restoration techniques: (1) sod transplantation, (2) natural colonization, (3) hay transfer and additions of seed mixtures for (4) wet and (5) bare soils. Over three years, we measured species richness, number of target species, Shannon diversity and similarity to reference sites. We asked: (A) What is the most effective technique for the restoration of lowland meadows? and (B) Is the applied restoration method more important than abiotic site conditions? We included 66 plots (reference and donor sites: 8 plots, restoration sites: 58 plots) in our study. We sampled data on species composition (4 m × 4 m plots) in three consecutive years since restoration initiation, estimated the slope inclination and analyzed soil parameters (K, P, pH). In general, species composition developed towards the reference vegetation for all techniques but sod transplantation produced by far the best result in terms of species richness and similarity to reference sites. By comparison, hay transfer and natural colonization produced intermediate results but performed better than seeding; the latter led to homogenous, species-poor swards. Soil preparation and abiotic site conditions played a minor role in this early stage of the restoration process, though these factors may gain importance in a longer time frame. We found sod transplantation to be a superior method for lowland meadow restoration in our study area but managers must consider its destructive nature and high costs, which might outweigh its benefits. In this light, hay transfer and natural colonization - or a combination of different techniques - could provide less destructive and more cost-effective alternatives.