A combination of restoration techniques results in high value grasslands.
In grassland restoration actions two contrasting approaches are used most often worldwide: technical reclamation or spontaneous succession. Technical reclamation in most cases means the addition of seeds of target species by hay transfer or seed sowing. An alternative approach is spontaneous succession, where no seeds are added and the grasslands are left to recover naturally. Costly technical reclamation is preferred worldwide despite several promising examples of spontaneous recovery of grasslands; this is especially true when there is an urgent need to heal landscape scars, prevent erosion or suppress weeds.
In our recent paper we pointed out the cost-effectiveness of spontaneous recovery processes in grassland restoration, studying recovery of loess grasslands in extensively managed lucerne (Medicago sativa) fields. Our results suggest that the recovery of initial loess grasslands does not require technical reclamation methods in lucerne fields if nearby native grasslands are present as a seed source. We found that lucerne fields were transformed into loess grasslands dominated by native perennial grasses by regular. Similar results were found under the more common and costly technical reclamation method of sowing low diversity seed mixtures. The full recovery of the species richness of loess grasslands requires longer time and/or should be facilitated by the introduction of some of the target species. The transfer of hay and/or low intensity grazing combined with continued mowing can be an option to facilitate the establishment of desirable species.
Our study provides a promising example of the combination of spontaneous succession and technical reclamation in grassland restoration. Sowing lucerne in abandoned fieldsand following this with extensive management offers a cost-effective solution from both agricultural and conservation point of view.
In particular, there is (i) no weed dominated stage, (ii) no intensive litter accumulation, (iii) Lucerne gradually decreases in abundance once re-sowing and/or fertilizing stop so we there will be a lower microsite limitation rate compared to technical reclamation only where competitor grasses are sown (iv) finally, combination of succession andtechnical reclamation is cheaper than technical reclamation only, and providesa high value hay harvest especially for the first few years in lucerne fields.
References:
Török P, A Kelemen, O Valkó, B Deák, B Lukács & B Tóthmérész. 2011. Lucerne dominated fields recover native grass diversity without intensive management actions. Journal of Applied Ecology 48: 257-264.
