Herbivore exclusion and water availability improve success across 76 translocations of 50 threatened plant species in a biodiversity hotspot with a Mediterranean climate

The ultimate goal of threatened plant translocations is to establish self-sustaining populations. Lessons learnt from plant translocations can inform future translocations and improve conservation outcomes via adaptive management. We assessed translocation success for 76 translocations of 50 species established as part of recovery programmes between 1998 and 2016 in the Southwest Australian Floristic Region (SWAFR), a biodiversity hotspot with Mediterranean-type climate. We used a series of Bayesian hierarchical models to assess translocation success as measured by plant survival, height growth, crown growth, and reproduction (flowering and fruiting). We found that fencing to prevent vertebrate herbivory improved survival, irrigating plants over the first two summer dry periods improved the likelihood of reproduction, and where the rainfall increased above the 30-year average in the two years following planting, it positively influenced survival, growth, and reproduction. We recommend that fencing to prevent herbivory should be broadly considered in threatened plant translocations, while irrigation to improve translocation success would benefit plant species in Mediterranean-type ecosystems and other dryland environments.