Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Biodiversity and Conservation [23 p.] Red List Pre-assessments Islands Tracheophytes French overseas territories Endemics RÉUNION MAYOTTE GUADELOUPE MARTINIQUE NOUVELLE CALÉDONIE TAAF AMSTERDAN ILE KERGUELEN CROZET, SAINT PAUL ILE EPARSES ILES 2023 fdi:010087436 ENG Biodiversity and Conservation 0960-3115 ISI:000922729900001 10.1007/s10531-023-02544-8 https://www.documentation.ird.fr/hor/fdi:010087436 https://www.documentation.ird.fr/intranet/publi/2023-04/010087436.pdf [Early access] Horizon (IRD) Assessment methods have been developed to estimate a preliminary conservation status for species and subsequently to facilitate the building of Red Lists. Such pre-assessment methods could be particularly useful in the French Overseas Territories (FOTs) where Red Lists tend to be out-dated or absent and where a high number of endemic species face detrimental anthropogenic pressures. We first aimed to conduct a preliminary assessment (hereafter, pre-assessment) of the conservation status of endemic plants from Guadeloupe, Martinique, Reunion, Mayotte, French sub-Antarctic islands, New Caledonia, and Scattered Islands. We then compared the various methods used in conducting the pre-assessment and discussed ways to adapt these methods to small territories. We compiled occurrence data of endemic species identified thanks to a previous taxonomic work and pre-assessed their conservation status under Red List criteria A and B and the use of a Random Forest algorithm. We then measured the accuracy, specificity, and sensitivity of each method based on existing Red Lists. The Random Forest algorithm and a method based on range-size performed best at correctly attributing conservation status. Using these pre-assessment methods, we estimated that up to 60% of the endemic flora of the FOTs is potentially threatened. Range restriction but also anthropogenic pressures were key factors that explained these risks. Pre-assessment methods are useful tools to get a first measure of species conservation status. These methods should be adapted to the territories considered and their conservation issues in order to reach a good performance. 082 ; 076 UR232 / UR123 Barbade