邻体密度和生境异质性共同驱动高黎贡山中山湿性常绿阔叶林幼苗多度OA

To understand the crucial dependency factors of seedling abundance with a diameter at breast height(DBH)<1 cm in a mid-montane moist evergreen broad-leaved forest of 4 hm2 Gaoligong Mountains,the generalized linear mixed models were used to analyze whether neighbor density and habitat factors shaped seedling abundance at the community and species level,and whether the strength of them varied with temporal.The results showed that:(1)The effect of neighbor density and habitat factors on all seedling abundance were significant and gradually strengthen at the community level.The positive correlation of common species with heterospecific neighbor density increased significantly,while no correlation with environmental factors.The seedling abundance of rare species reflected non-significant with neighbor density and environmental factors.(2)At species level,the seedling abundance of Psychotria morindoides was only slightly and significantly negatively associated with elevation in 2022.Neighborhood density and environmental heterogeneity had significant positive effects on seedling abundance of Myrsine semiserrata in 2020-2023,indicating that there was a positive density dependence.The seedling abundance was higher in higher canopy opening,elevation and soil potassium.However,these correlations were non-significant on the seedling abundance of Symplocos stellaris var.aenea in the four periods.This study indicated that the seedling abundance is driven by both neighbor density and habitat heterogeneity.The strength of neighbor densities and habitat factors differs greatly among community,species and temporals,which relative importance of variables can maintain the community diversity in the plot.