关键词: 凹叶厚朴, 年龄结构, 更新特征, 幼苗生长动态, 更新障碍

Abstract:

Magnolia officinalis subsp. biloba is an endangered plant species that has been categorized as one of the second grade state protection wild plants of China. The overexploitation of this species due to its high medicinal value has resulted in resource reduction, population declining, and community recession. This research was undertaken to explore the regeneration characteristics of M. officinalis subsp. biloba and the factors that may limit the process. A field survey of the species was undertaken and the age structure, seedling characteristics, and obstacles to regeneration were identified. The frequency distribution of sizes of M. officinalis subsp. biloba individuals was found to be a typical J-type, suggesting that the population would maintain stability over a relatively long time. Sprouts occupied a large proportion of three communities studied and the proportion increased as the canopy density increased. The sprouts showed no significant difference in average branch number, height, and diameter at breast height (DBH) over various densities while the seedlings decreased in height and DBH as the canopy density increased. The age structure of seedlings and sprouts displayed great variability in different communities. Seedling regeneration was common under the coniferous and broad-leaved mixed forest. Regeneration of this species under various forest canopy varies in the order of broad-leaved forest

Key words: Magnolia officinalis subsp. biloba, age structure, regeneration characteristics, seeding dynamics, regeneration obstacle