Contemporary Environmental Drivers of European Plant Distributions

Aim: Understanding the contemporary environmental conditions determining plant species distributions is crucial. Here, we quantified the relative importance of climatic, edaphic, hydrological, topographic, and land use drivers of the European vascular flora and tested whether driver hierarchies vary across species groups and ecological characteristics, spatial scales and bioregions. Location: Europe and adjacent areas. Time Period: 1990–2022. Main Taxa: Vascular plants. Methods: We compiled > 20 million occurrence records from GBIF, EVA and other databases for ~11,500 vascular plant species, mapped onto a 1 km × 1 km grid. Gradient boosted decision trees were fitted with 36 uncorrelated variables and evaluated through spatial block cross-validation. Variable contributions were assessed using SHAP (SHapley Additive exPlanations) values at continental and bioregional scales. Using SHAP profiles, we also clustered species with similar environmental responses and tested how these groups relate to life history, growth form, habitat and CSR ecological strategies. Results: At the continental scale, climate and soil emerged as the dominant environmental drivers of plant distributions. Six response groups were identified, which showed that less dominant drivers—hydrology, topography and land use and cover— strongly influenced certain species. Groups were significantly associated with ecological characteristics such as growth form. Beyond group-level differences, we also found clear geographical patterns and scale-dependent shifts in variable importance: within bioregions, local drivers gained importance relative to continental constraints. Main Conclusions: Plant species distributions in Europe are primarily shaped by climate and soil among contemporary environmental drivers, but species-specific ecological characteristics, scale and spatial context modulate the hierarchy of drivers. Recognizing response diversity is essential to avoid oversimplified generalizations. A multi-scale framework that integrates climatic gradients with context-dependent drivers and dispersal limitations will improve predictions of plant biodiversity responses to global change.