Unraveling large-scale species richness patterns and drivers is central to ecology. While climate, soil, topography, and human activities are widely recognized as key drivers, their relative contributions to Pinus L. diversity (especially in Europe) remain inconclusive due to scale dependence and methodological variations. This study integrates distribution data for 17 European Pinus species along with climatic, soil, topographic, and anthropogenic variables and employs Random Forest and Structural Equation Modeling to analyze spatial patterns of overall, wide-ranged, and narrow-ranged species richness, quantifying factor importance and driving pathways. Additionally, diversity hotspots were identified using the complementarity algorithm and top 5% richness methods. Results indicate higher species richness in topographically complex western Europe. Climatic seasonality emerges as the primary direct driver of overall and wide-ranged species richness. Human activities exert strong positive direct effects on all species groups and produce substantial indirect effects by altering the environment, with a relatively prominent influence on narrow-ranged species richness patterns. Although existing European Pinus hotspots are generally well-protected, conservation gaps in southwestern Europe necessitate targeted strategies. This study elucidates the regulatory mechanisms of Pinus species richness patterns across different distribution ranges, highlighting the need for differentiated conservation under ongoing climate change and anthropogenic pressures.

Climate change has significantly affected the geographical distribution and richness patterns of plant species worldwide. Pinus is a major component of many temperate and montane forests in the Northern Hemisphere and is important for carbon storage, climatic buffering and timber production. Here, we utilized the MaxEnt model and integrated global occurrence records of 113 Pinus species, predicting climatic envelopes and diversity distribution patterns under three emission scenarios for the 2050s and 2070s, while also identifying diversity hotspots, high-decline regions, and conservation gaps. As global overheating and linked climatic variations intensify, climatically suitable areas for Pinus are projected to shift poleward. Using projected climatic envelope contraction as a screening criterion, 7.96%–44.25% of species qualified as climate-vulnerable across scenarios. Additionally, Pinus demonstrates high species richness in North America, the Mediterranean region, and mid-latitude mountainous regions of East Asia. Our predictions reveal that species richness distribution will be notably influenced by climate change, with impacts gradually intensifying as climate change progresses. Fortunately, the current coverage rate of protected areas in diversity hotspots exceeds 92.31%, and the conservation gaps primarily occur in Mexico. It is anticipated that over 86.46% of hotspot areas will remain protected in the future. However, new conservation gaps may arise in eastern North America and southeastern Europe; these regions should be prioritized in future conservation planning. Our research enhances current understanding of how species might respond to the challenges of climate change while also providing practical guidance for priority conservation planning targeting both biodiversity hotspots and high-decline regions.