RT Journal Article T1 Data fusion and integrated species distribution models for three endangered ferns (Culcita macrocarpa, Diplazium caudatum, and Pteris incompleta) in a Mediterranean biodiversity hotspot. A1 Ruiz-Valero, Ángel A1 Pereña-Ortiz, Jaime Francisco A1 Salvo-Tierra, Ángel Enrique K1 Fitogeografía - Modelos matemáticos K1 Biogeografía K1 Helechos K1 Plantas en vías de extinción K1 Análisis de datos K1 Biodiversidad - Mediterráneo (Región) AB Introduction: Accurately modeling the distribution and abundance of rare and threatened species is considered critical for informing conservation strategies under increasing environmental pressures. Three threatened paleomediterranean relict ferns, Culcita macrocarpa, Diplazium caudatum, and Pteris incompleta, are restricted to climatically stable microhabitats within Los Alcornocales Natural Park (southern Spain), rendering them particularly vulnerable to environmental change. Methods: A joint-likelihood framework was employed within Integrated Species Distribution Models (ISDMs) to estimate spatiotemporal abundance of the three fern species. Structured abundance data (2014–2023) from the Andalusian Fern Recovery Plan were integrated with opportunistic presence-only records obtained from Global Biodiversity Information Facility (GBIF). Twenty-two model configurations were tested to evaluate the benefits of multi-species modeling and data-fusion strategies. Results: Predictive performance was improved by multi-species modeling, with shared ecological and spatial structures being captured more effectively. Spatiotemporal random effects were found to be more influential than fixed effects, reflecting local-scale heterogeneity in fern distributions. Spatiotemporal patterns were captured most effectively by the model excluding GBIFdata fusion. Signs of overfitting were observed in the model incorporating data fusion, with GBIF inclusion failing to consistently improve predictive performance due to limited observations and spatial biases. Population trends were indicated to be generally stable, with localized increases and limited declines documented in two C. macrocarpa populations. AB Discussion: The value of ISDMs in leveraging complementary data sources is demonstrated by these findings, providing an effective framework for conservation planning in data-limited systems facing environmental change. PB Frontiers YR 2025 FD 2025-12-02 LK https://hdl.handle.net/10630/40977 UL https://hdl.handle.net/10630/40977 LA eng NO Ruiz-Valero A ´, Pereña-Ortiz JF and Salvo-Tierra A ´E (2025) Data fusion and integrated species distribution models for three endangered ferns (Culcita macrocarpa, Diplazium caudatum, and Pteris incompleta) in a Mediterranean biodiversity hotspot. Front. Plant Sci. 16:1650159. doi: 10.3389/fpls.2025.1650159 DS RIUMA. Repositorio Institucional de la Universidad de Málaga RD 21 ene 2026