Possibilities of restoration of natural or seminatural grasslands

Abstract

The number of natural grassland restoration projects increased in the last decade in Hungary, and probably the area of restored grasslands will be significantly extended in the next years due to New National Rural Development Program. To contribute to the success of this activity, in this paper we review the most important theoretical and practical aspects of natural grassland restoration methods. In the course of grassland restoration, habitats dominated by grasses and/or sedges have been restored in place of arable lands. In order to perform “natural” restoration, we should consider the ecological conditions of the landscape, and reconstruct natural or seminatural grasslands including of native plant species. Essentially, rehabilitation of natural landscape is supported also by creating new seminatural grassland patches. The basic principles of the natural grassland restoration are:
 1. When a spontaneous secondary succession starts to proceed on an abandoned field without invasion of any alien plant species, the re-ploughing of the abandoned field has to be ignored.
 2. Generally, the old fields surrounded by species-rich natural or seminatural grassland pathes can succesfully be restorated. Then, as a consequence of newly restored vegetation patches the recovery of the whole landscape can be accelerated. Furthermore, by restoring isolated grassland patches surrounded by arable lands a more diverse landscape pattern could be developed.
 3. Spontaneous secondary succession of grasslands should be assisted.
 4. The development of typical species composition of a seminatural grassland can be promoted by methods of spreaded hay. For successful process the hay has to be cut in a habitat type similar to ones that will be restored.
 5. Applying seed-mix for sowing can be useful to prevent spreading weeds drastically in the early stages of succession.
 6. Ideally, the seed-mix is originated from own harvesting or gathering from similar (or the same) habitats. If it is not possible, commercially available seed-mix can be applied, in which the dominant species is the same as in the restored habitat, with similar proportion.
 7. Seed-mix consists of alien species has to be avoided.
 8. If the composition or structure of the restored grassland is not appropriate after some years, the renewal of the grassland could be necessary. During the improvement process the reploughing of the restored grassland is avoided, but spreading seeds or hay, and direct sowing can be applied.
 9. The loading of nutrient is not necessary in any stages of grassland restoration.
 10. Applying chemicals is avoided; any herbicides can be used only when extensive invasion of alien plant species occurs.
 11. The mechanical intrusions on soil are also avoided.
 12. The restored grasslands is required regular or continuous management, which could be a preserving mowing or moderate grazing. The aspects of nature conservation should be considered.