The spontaneous recovery of plant communities after severe anthropogenic disturbances has often to face two main obstacles: the reduced propagule pressure of target species and the high dispersal and establishment potential of unwanted species, particularly due to the increased soil fertility. An experiment was carried out 10 years ago to address the question: what are the most efficient restoration treatments to restore such plant communities? After the rehabilitation of an herbaceous sheep- grazed habitat in a formerly intensively cultivated orchard in a Mediterranean steppe in France, four experimental techniques were applied to restore the plant community: i) topsoil was removed to lower ruderal species seed banks and soil trophic levels, ii) nurse species were seeded to rapidly occupy niches, and then to provide safe sites for target species once sheep grazing has been reintroduced, iii) hay was transferred to provide local species seeds and iv) soil was inoculated to provide local species propagules with associated microorganisms and to lower soil trophic levels. Four years later, above-ground vegetation physiognomy was rehabilitated, and some treatments had great results: species richness was restored and community structure was half restored by soil transfer and topsoil removal. Ten years later they did not improve more but the other treatments, including the control, have greatly improved in diversity and structure, reaching the restoration level of the latter treatments. These results will be discussed, as well as the merits of having good results at the very beginning of a restoration project but with no better dynamics after.
Audio/Video, Conference Presentation, SER2019
Pre-approved for CECs under SER's CERP program
Society for Ecological Restoration