Comparative Analysis of the Volume Growth of Oaks (Quercus) Across Regions of China

Abstract

Oaks (Quercus) are a widely distributed and ecologically important genus in forests globally. However, their growth varies considerably across regions that vary in climate and soil conditions. Here, we systematically analyze the dynamics and regional differences in the volume growth of oaks, with the aim to provide scientific evidence useful for the sustainable management and ecological stewardship of oak forests. The results show that: (1) There are significant differences in the volume growth of oaks among regions of China. The southwestern region has the highest volume growth, with an average of 122.90 m³∙hm⁻², which is significantly higher than that of other regions, including the northeast (104.06 m³∙hm⁻²), northwest (92.19 m³∙hm⁻²), southeast (91.13 m³∙hm⁻²), north central (53.47 m³∙hm⁻²), and south central region (49.26 m³∙hm⁻²). The observed differences are mainly attributed to the varying age group structures across regions, with a higher proportion of near-mature and mature forests in the southwestern, northeastern, and northwestern regions, while other regions have a larger proportion of young and middle-aged forests. (2) The volume growth of oak trees is significantly age dependent. In the early growth period (e.g., the first 100 years), they exhibit rapid growth, before entering a relatively stable growth phase. The southeastern region shows the highest growth, with the north central regions had slower growth. Notably, oaks in the northwestern region exhibit clear signs of early aging. (3) Climate and site conditions have a decisive impact on the growth of oak trees. The warm and humid climate of the south, along with diverse site conditions, provides a favorable environment for oak growth, whereas the cold and dry climatic conditions in the north somewhat limit their growth potential. Based on this, we recommend developing differential forest management strategies according to the climatic and site conditions of the regions, optimize stand structures, and promote the sustainable development of oak resources.