How can we ensure the survival of a rare and threatened plant in degraded coastal environments? This is the question being studied for Astragalus tragacantha, a spiny shrub found mainly on the Mediterranean coast of southeastern France. Nearly 90% of the recorded individuals are located in the Calanques National Park, south of Marseille, where populations face significant human pressure.
As part of the European LIFE Habitats Calanques project, transplantations were carried out at ten sites within the National Park to strengthen existing populations or reintroduce them along its coastal distribution.
Published in the journal Ecological Engineering, a study led by Lucie Miché and her colleagues reveals, after 53 months of monitoring, an average survival rate of 26%, with significant differences between sites.
Plants survive better in rocky microhabitats, while richer soils promote their growth. However, competition from herbaceous plants in these richer soils appears to limit their survival.
These findings underscore the importance of considering ecological conditions at a very local scale to ensure successful transplantation operations. Beyond plant survival, the choice of microhabitats must also promote their development and reproduction to sustainably contribute to the conservation of this threatened species.
This fruitful collaboration between scientists, managers, and decision-makers has provided essential indicators for better targeting ecological restoration operations and enhancing the effectiveness of conservation actions for threatened plants.
