Seeds from species-rich grasslands: Production patterns and use for ecological restoration

Biodiversity loss has become an impelling global concern and the restoration of degraded or damaged habitats, including agricultural semi-natural vegetation, is a vital aspect for its conservation. The species-rich grasslands are defined as one of the most important habitats with a high level of biodiversity connected with rural areas and their conservation is a goal of the “European Union biodiversity strategy to 2020” (EU, 2011). A big limitation of their recover is the lack of available native species seeds in the conventional market and locally harvesting of native ecotypes of grassland species is often necessary. This approach is in line with the conservation principles of the ecological restoration. The mixture of seed which can be collected from semi-natural meadows can have different characteristics in relation to the type of grassland management. The knowledge on the availability and characteristics of the seed of the main meadow species can facilitate the seed use for different agricultural and urban environments. A study of the fertilisation effects on the seed production was therefore performed with particular attention to the seed production of forbs, which are an important biodiversity component, often threatened by management intensification. Compared to grasses forbs increased less the viable seed production at higher level of fertilisation. The higher increase of seed production for light-seeded grasses was an important reason for higher grass competitivity in more fertilised grasslands. Grasses showed also higher dormancy which is an important feature affecting their annual presence in the grassland and their behavior in restoration. To study the success of grassland restoration with seed of native species in real situations, multi-years monitoring were carried out at two high-extent alpine ecological restoration. The study of the development of vegetation during the following years has shown that the use of the green grass technique allows to transfer a large number of species, even if the percentage of transfer efficiency tends to decrease with the increase of the number of species in donor meadows. The restored grasslands showed a botanical composition comparable to the standard vegetation of the meadow in the same geographical region, which is not necessarily the same as the donor's grassland.