Background and aims – Intense agriculture phases on old plant communities, such as Mediterranean steppes, can lead to low resilience. Two main obstacles to the spontaneous recolonization of these plant communities are often the low dispersal of target species and the high dispersal and establishment potential of unwanted species. The aim of the study is to find the most efficient restoration treatments to restore these plant communities. Methods – After the rehabilitation of an herbaceous sheep-grazed community on a formerly intensively cultivated orchard in the last French Mediterranean steppe (La Crau, Provence, France), four experimental restoration treatments were applied to restore the steppe plant community: (i) topsoil removal to lower ruderal species seed banks and soil trophic levels, (ii) nurse species seeding to rapidly occupy niches, and then to provide safe sites for target species once sheep grazing is reintroduced, (iii) hay transfer to provide local species seeds, and (iv) soil transfer to provide local species propagules with associated microorganisms. One year later, plant species richness, composition and diversity are compared. Results – Although the communities developing on areas seeded with nurse species and where topsoil was removed differed most widely from the reference ecosystem, i.e. steppe, these restoration treatments succeeded in achieving their goal by significantly lowering the abundance of unwanted dominant species. While hay transfer did not have a significantly higher species richness than that of the rehabilitated area, it showed promising results, as some germinations of target species were observed. One year only after the treatment was applied, soil transfer provided a community richness and composition very close to that of the reference ecosystem, but not with the same vegetation structure. Conclusion – In order to restore plant community composition, the more the treatment strengthens community dispersal, the more efficient it is. The gain in efficiency is closely linked with the cost of the treatment.

FORMER AGRICULTURAL LAND; GRASSLAND; HAY TRANSFER; NURSE SPECIES SEEDING; PLANT COMMUNITY COMPOSITION; SOIL TRANSFER; SPECIES RICHNESS; TOPSOIL REMOVAL