The protection and propagation of rare and endangered species are key to the preservation of their population development; however, due to the scarcity of individuals, the potential effects and status of rare and endangered species in the whole forest ecosystem are still poorly understood. Using data from a 60 × 140 m forest dynamic monitoring sample of the Carpinus tientaiensis (Betulaceae) species in Zhejiang of Southeast China. We assessed the population distribution and diameter at breast height (DBH) structure of the Carpinus tientaiensis species, which was a rare and endangered species, as well as intra- and interspecific correlation with other species. The results show that saplings (1 cm ≤ DBH < 5 cm) and juveniles (5 cm ≤ DBH < 10 cm) were more aggregated than larger individuals (DBH ≥ 20 cm) of Carpinus tientaiensis. The DBH size structure of all the trees shows an obvious inverted “J” distribution. With an increase in the DBH size category, the number of individuals gradually decreases. Due to the diffusion limitation, the spatial distribution patterns of all the tree individuals and roof geese in the sample land are increased at a small spatial scale, and as the spatial scale increases, the degree of aggregation decreases gradually. The relationship between different diameter stages of the population of Carpinus tientaiensis showed a consistent general trend. The spatial distribution of individuals with a large diameter on a small scale was significantly positively correlated (p < 0.001). With an increase in the scale, there was no significant correlation (p > 0.05) between individuals with a large diameter and individuals with a small diameter. There was no significant correlation (p > 0.05) between the population of Carpinus tientaiensis and other species in the sample, and the strong unidirectional competition of other species in the sample can be seen by the competition index. We found that interspecific competition restricts the growth and expansion of Carpinus tientaiensis, and it has adopted different ecological strategies to coexist with a population of common tree species occupying a similar living space.

Studying the factors influencing ecosystem regulation services in southwestern Zhejiang is of great significance for formulating reasonable pricing strategies for forest ecosystem regulation services and optimizing ecological security. This study constructed a theoretical framework for analyzing forest ecosystem regulation services and assessed the spatiotemporal evolution and influencing factors of forest ecosystem regulation services using InVEST model calculations and spatial autocorrelation analysis. The results showed that all ecosystem services of forests in the study improved from 2000 to 2019, with the exception of soil conservation. The water conservation function increased significantly from 2000 to 2019, with an overall increase of 3.53%. The biodiversity conservation function in 2019 also increased significantly, with an average increase of 2.16% compared with 2000. The synergies mainly occurred between water source regulation and soil conservation, soil conservation and biodiversity, and forest recreation and carbon storage. Forest Reserve was precipitation, canopy closure, elevation, and soil texture, and their driving forces differed at different time scales. The trade-offs mainly occurred between soil conservation and forest recreation, forest recreation and biodiversity, and carbon storage and biodiversity. The research results provide a reference for achieving ecological protection and high-quality development in the southwestern region of Zhejiang.