为探究小区域尺度下闽西常绿阔叶林区壳斗科（Fagaceae）物种丰富度的空间分异格局及关键环境影响因子驱动机制，采用二次多项式回归模型、Jaccard相似系数等对3 km×3 km网格单元的壳斗科植物进行分析。结果表明：随着海拔升高，该区域壳斗科物种丰富度呈单峰型变化趋势，峰值位于海拔>600~900 m区域，并且，海拔梯度差距越大，Jaccard相似系数越小。在水平空间上，该区域壳斗科物种丰富度以北纬25.2°、东经117.0°附近最高。根据Spearman秩相关系数和一元线性回归分析结果，壳斗科物种丰富度与海拔、年降水量、最湿月降水量、最干月降水量、干燥指数、距道路距离及降水量空间差异呈显著（P＜0.05）或极显著（P＜0.01）正相关，与地形湿度指数、年均温、最热月均温、最冷月均温、气温年较差、降水季节性、实际蒸散量、土壤质地、景观生态风险指数、景观干扰度指数、夜间灯光指数及气温空间差异呈显著或极显著负相关。层次分割分析结果显示：剔除共线性较强的环境因子后，筛选出的11个环境因子对壳斗科物种丰富度的独立贡献率合计13.58%，其中，最热月均温、气温空间差异和景观干扰度指数的独立贡献率较高。分段结构方程模型显示：能量因子、水分因子、人为驱动因子、生境异质性因子对壳斗科物种丰富度有直接影响，地形因子和土壤因子对壳斗科物种丰富度有间接影响，人为驱动因子和生境异质性因子还起到枢纽作用。综合分析认为，闽西常绿阔叶林区壳斗科物种丰富度的垂直分异格局符合中域效应理论，其水平空间分异格局呈随机分布状态。该区域壳斗科物种丰富度主要受水分-能量平衡机制调控，同时受生境异质性和人为驱动介导，其他环境因子则通过该路径产生间接效应。

To investigate the spatial differentiation patterns of Fagaceae species richness and the driving mechanisms of key environmental impact factors in evergreen broad-leaved forest region of western Fujian at a small regional scale, the analyses of Fagaceae plants in 3 km×3 km grid units were conducted by using quadratic polynomial regression models, Jaccard similarity coefficient, etc. The results show that with the increase of elevation, Fagaceae species richness in this region exhibits a unimodal variation tendency, and the peak value is in >600-900 m elevation zone, in addition, the larger elevation gradient differences, the smaller the Jaccard similarity coefficient. In the horizontal space, the Fagaceae species richness in this region is the highest near N25.2°, E117.0°. According to the Spearman rank correlation coefficients and simple linear regression analysis results, Fagaceae species richness shows significant (P<0.05) or extremely significant (P<0.01) positive correlations with elevation, annual precipitation, precipitation of the wettest month, precipitation of the driest month, aridity index, distance to road, and precipitation spatial difference, while demonstrating significant or extremely significant negative correlations with topographic wetness index, mean annual temperature, mean temperature of the warmest month, mean temperature of the coldest month, annual temperature range, precipitation seasonality, actual evapotranspiration, soil texture, landscape ecological risk index, landscape disturbance index, nighttime light index, and temperature spatial difference. The hierarchical partitioning analysis result shows that after removing environmental factors with strong collinearity, 11 selected environmental factors collectively explained 13.58% of the independent contribution rate in Fagaceae species richness, among which, the independent contribution rates of mean temperature of the warmest month, temperature spatial difference, and landscape disturbance index are relatively high. The piecewise structural equation model indicates that energy factor, water factor, anthropogenic driven factor, and habitat heterogeneity factor have direct effects on Fagaceae species richness, terrain factor and soil factor have indirect effects, and anthropogenic driven factors and habitat heterogeneity factors additionally serve as pivotal mediators. Comprehensive analysis suggests that the vertical differentiation pattern of Fagaceae species richness in evergreen broad-leaved forest region of western Fujian conforms to the mid-domain effect theory, while its horizontal spatial differentiation pattern exhibits random distribution characteristics. Fagaceae species richness in this region is mainly regulated by mediated water-energy balance mechanisms, and simultaneously regulated by habitat heterogeneity and anthropogenic driven factors, while other environmental factors exert indirect effects through this pathway.