Modeling the distribution of bryophytes threatened according to the European Red List in Türkiye under climate change

Introduction Climate change is expected to become one of the greatest threats to bryophyte diversity; therefore, predicting the future distributions of species is vital for effective conservation planning. However, the absence of a national bryophyte Red List and threat assessments in Türkiye represents a major shortcoming in terms of biodiversity conservation. To address this gap, we modeled the current and future potential distributions of bryophyte taxa naturally occurring in Türkiye that are classified as “Vulnerable” (VU), “Endangered” (EN), or “Critically Endangered” (CR) on the European Red List. Methods From among the 73 threatened taxa identified in Türkiye, 36 species with at least five (≥5) recorded occurrences were selected for modeling. Species distribution models were developed using MaxEnt v3.4.4 under current climate conditions and projected to 2021–2040 and 2081–2100 under two climate scenarios (SSP1-2.6 and SSP5-8.5) and two global climate models with contrasting climate sensitivities (HadGEM3-GC31-LL and MIROC6). Results Precipitation-related variables, particularly precipitation seasonality (BIO15), were the most important predictors for most species, whereas temperature-related variables predominated for the species of the continental interior and mountain regions. Projections for 2081–2100 under the SSP5-8.5 scenario indicate that 15 bryophyte taxa (14 mosses and one liverwort (Scapania verrucosa)) will experience substantial reductions in their climatically suitable areas, consistently under both climate models, and some species are projected to lose nearly all of their climatically suitable areas. The moss species at highest risk of extinction were predominantly acrocarps and small taxa (with the exception of Brachythecium geheebii and Palamocladium euchloron). Discussion Our findings present the first climate-based conservation assessment for threatened bryophytes in Türkiye and provide a scientific foundation for the creation of a National Bryophyte Red List, the identification of priority bryophyte conservation areas, and the development of evidence-based conservation planning under future climate change conditions.