Forecasting Habitat Shifts in Euro-Mediterranean Orchids Protected Under Directive 92/43/EEC

While the main diversification centers of Orchidaceae Juss. are located in neotropical-like climates, Europe, and particularly the Mediterranean basin, has remarkable orchid biodiversity. The present study aims to model the habitat suitability of Mediterranean orchid species listed under the Directive 92/43/EEC: Cypripedium calceolus L., Dactylorhiza kalopissii E.Nelson, Himantoglossum adriaticum H.Baumann, Himantoglossum jankae Somlyay, Kreutz & Óvári, Liparis loeselii (L.) Rich., Ophrys argolica H.Fleischm., Ophrys kotschyi H.Fleischm. & Soó, Ophrys lunulata Parl. and Spiranthes aestivalis (Poir.) Reich. The Bayesian Additive Regression Trees algorithm is employed to conduct automated variable selection and, subsequently, to model the current potential distribution. Solar radiation and the continentality index stand out as the most important distribution predictors. The Miller calibration slope is found to be inadequate (>2.0) for taxa with limited occurrences. Finally, the medium- (2051–2075) and long-term (2076–2100) viability under climate change scenarios SSP2-4.5 and SSP5-8.5 is assessed for high-prevalence orchids (Cypripedium calceolus, Himantoglossum adriaticum, Liparis loeselii and Spiranthes aestivalis). Our results reveal a marked contraction of suitable areas for Cypripedium calceolus (21–55%), Spiranthes aestivalis (29–60%), and, especially, Liparis loeselii (57–87%), which would reach the critically endangered status under the SSP5-8.5 scenario. Our findings underscore the urgent need to incorporate refined ecological modeling into conservation strategies, thereby informing management decisions and policy frameworks aimed at safeguarding one of Europe’s most emblematic and vulnerable plant lineages.