Research on the construction mechanism of warm temperate deciduous broad-leaved forest communities based on plant functional traits in northern China，

The mechanism of community assembly has always been a core aspect of community ecology. Exploring the interspecific interactions and the distribution characteristics of different organ traits, as well as their main influencing factors, during community development is of great significance for community assembly, succession, and adaptation to climate change. However, artificial forests cannot compare with natural forests in terms of biodiversity conservation and ecosystem multifunctionality. Therefore, an in-depth exploration of the assembly mechanisms of natural forest communities is beneficial for maximizing their ecological, economic, and social benefits. Current research mostly focuses on single-organ, single-functional groups and their responses to single environmental variables. There is little exploration of the diversity of species and the distribution patterns of functional traits in different functional groups and organs during the assembly process of natural communities, as well as their environmental explanations. This study takes the Quercus wutaishanica as community in the warm temperate deciduous forest of northern China as an example. Community surveys were conducted in Quercus wutaishanica communities spanning five provinces from west to east in northern China, including different functional groups such as trees, shrubs, and herbs. Samples of leaves, twigs, and fine roots were collected, and their morphological and chemical functional traits were measured. Environmental factors including soil and topography were also measured. This study aims to deeply explore the interactions between functional traits and species in natural forest communities and their environmental explanations, elucidate the ecological processes involved in the assembly process of warm temperate deciduous broad-leaved forest communities in northern China, and reveal their community assembly mechanisms. The goal is to provide a theoretical basis for biodiversity conservation, the restoration and reconstruction of natural secondary forests, and responding to climate change.