Abstract: Deciduous oak forest is one of the typical vegetation types in temperate and subtropical mountain zones in China. However, the patterns and determinants of the structural characteristics of these forests remain poorly understood. We investigated 682 oak forest plots across China to characterize the community structures of the oak forests and analyze the underlying factors controlling their spatial patterns. Across all plots, the overall mean values were 13.7 cm, 10.0 m, 1468 stems/ha and 24.3 m²/ha for the diameter at breast height (DBH), height, stem density and total basal area (TBA) of trees, respectively. The average species richness was 6 species/600 m², 10 species/100 m² and 4 species/1 m² for the tree, shrub and herb layers, respectively. As latitude increased, the mean tree height, stem density, TBA, tree species richness and shrub species richness decreased, and the mean DBH did not show a significant trend, while species richness of herbs increased significantly. Climatic and anthropogenic variables could explain more variations in mean DBH, mean tree height, TBA, tree species richness, shrub species richness than those in stem density and herb species richness. Further analysis showed that precipitation-related climatic factors were major factors shaping the spatial patterns of community structures. Our findings provide a basis for recognizing the biogeographic patterns of oak forest structures and their responses to global change in China.

Key words: Quercus, deciduous oak forests, structural characteristics, climate, human disturbance, China