Objective Taking Liriodendron chinense natural forest in Hefeng county, Enshi Tujia and Miao Autonomous Prefecture, Hubei Province as the research object, to analyze the species composition and stand space structure were analyzed, and describe the forest structure characteristics of L. chinense.

Method Forty L. chinense plots of 20 m × 20 m were established in two typical distribution areas, respectively, each tree in the plots was positioned and measured. The Winkelmass software and R 3.5.1 were used to calculate the uniform angle index (W), dominance (U), mingling (M) and crowding degree (C) for trees with DBH ≥ 5 cm, the distribution of univariate distribution, the bivariate distribution and quadrivariate distribution characteristics were presented and analyzed.

Result There were a total of 251 species in the L. chinense community, including 88 species of trees, 61 species of shrubs, 77 species of herbs and 25 species of woody lianas, belonging to 172 genera of 76 families. L. chinense population was the dominant population in the community, but the dominance was not obvious. The uniform angle index of the L. chinense natural forest was 0.566, and the overall distribution was slightly aggregated. The tree growth was in a neutral state (U = 0.508), the tree species were in a highly mixed state (M = 0.742), the stand density was high, and the mean crowding degree was 0.865. The uniform angle index had a certain influence on the dominance, mingling and crowding degree, and the mixing state and stand density were mutually promoting.

Conclusion The species of L. chinense natural forest in the study area are highly mixed and estimated during the middle and late stage of natural forest succession. The competition relationships between individual trees should be adjusted in the process of forest management, in order to maintain the stability and sustainable development of the forest structure. It is necessary to reduce the phenomenon of the aggregation of same species, to selectively remove individual trees at absolute disadvantage and weak mixed degree, so as to improve the forest environment, and promote natural regeneration.