Spatial Patterns and Associations of Tree Species in a Temperate Forest of National Forest Park, Huadian City, Jilin Province, Northeast China

Analyzing the spatial patterns and associations among tree species may help to elucidate the importance of the ecological processes behind population formation and the mechanisms of species coexistence. To explore this mechanism, we mapped and studied eight dominant tree species in Korean pine broad-leaved mixed forests in a temperate forest region in Jilin Province, Northeast China. The spatial distribution patterns and spatial associations of the eight dominant tree species at different life history stages and spatial scales were analyzed using the second-order spatial point pattern method based on pair correlation functions. The results indicated the following: (1) The diameter class structure of all individuals in the plots showed an obvious "L" shape, indicating that the community was well regenerated and belonged to a growing stand. (2) The distribution of trees was affected by scale, size, and habitat heterogeneity. The degree of aggregation decreased as the diameter class increased. (3) Out of the 56 pairs of individuals, a small number showed a significant correlation, while most were negatively correlated. It is concluded that seed dispersal limitations, competitive ability, and topography and light requirements may influence the spatial distribution and association of species to maintain species coexistence and diversity in Korean pine broad-leaved mixed forests. The results can provide insights into the ecological processes of population assembly, the mechanisms of species coexistence, and the relationship between forest management and restoration.