Species composition, structure, and spatial distribution of shrubs in broad-leaved Korean pine (Pinus koraiensis) mixed forest in Changbai Mountains

Based on the shrub census of 600 quadrats (5 mx5 m) in a 25 hm ² plot of broad-leaved Korean pine mixed forest in Changbai Mountains, this paper analyzed the species composition, structure, and spatial distribution of shrubs in the forest. A total of 18 shrub species, including 6435 shrub individuals and 11369 stems, were found in the census, with Philadelphus schrenkii, Corylus mandshurica, and Acer barbinerve being the dominant species. P. schrenkii had the highest amounts of individuals and stems, occupying 40. 6% and 33. 4% of the total, respectively. There existed great differences in the clumpy ratio, stem number per clump, crown size, and basal diameter among the shrub species, and the height of different shmb species also varied significantly, with obvious vertical stratification observed in the community. The dominant species P. schrenkii had a wide distribution, while Sorbaria sorbifolia, Spiraea chamaedrjfolia, S. salicifolia, and Euonymus pauciflorus had obvious heterogeneous distributions.