Anticipating plant translocation in land-use projects: a case study of Helianthemum marifolium

ABSTRACT In the context of a land development project, we carried out an experimental translocation before the proposal of mitigation hierarchy related to the project. By doing this early, we obtained results on the experimental translocation and thus better inform the measure proposed as part of the project. This project is likely to impact a large population of the plant species Helianthemum marifolium, which has a national protected status in France. We present here the pre-translocation phase, proposing different methodologies to better understand and prepare for a translocation. First, we studied the potential future distribution based on climate factors. Then, we sought to improve our knowledge of the local populations studied. To do this, we carried out pollinator surveys and a study of reproductive success. Finally, we presented the results of germination and cultivation tests, which enabled us to determine the mechanism for breaking dormancy and the most favourable substrate for growing, and we compared potential host sites regarding soil analyses. These different aspects allowed us to determine a protocol to be followed for a more significant translocation of this species. This case study illustrates requirements of the pre-translocation planning and can be used to inform future translocations of Helianthemum marifolium. The case study also presents methods other translocation practitioners can use to improve their protocols in the future.