濒危植物闽楠幼苗更新及环境解释

为了更好地理解濒危植物闽楠幼苗天然更新与微环境的关系,以广西富川县蚌贝村闽楠天然林胸径5.0 cm以下的更新个体为研究对象。基于0.64 hm₂^{固定监测样地调查数据,采用Pearson相关系数、冗余分析等方法对幼苗更新密度与样地微环境因子关系进行分析。结果表明：(1)闽楠小幼苗更新个体数最多,随龄级增加更新密度呈下降趋势；幼苗向幼树转化率低,小幼苗向中幼苗转化率是闽楠更新成功的关键阶段；(2)闽楠幼苗更新密度与样地灌木层高度、最近母树距离、灌木层覆盖度极显著正相关,与样地光照、草本层覆盖度显著负相关； (3)灌木层高度、最近母树的距离、灌木层覆盖度、叶面积指数、光照、草本层覆盖度、凋落物厚度、土壤盐分是影响闽楠幼苗更新的主要微环境因子,光照和草本层覆盖度是闽楠幼苗更新的限制因子。因此,降低光照强度、减少草本层的覆盖度、增大灌木层的覆盖度等有利于闽楠种群更新发展。}

Characteristics and environmental interpretation of seedling regeneration in the endangered species Phoebe bournei

In order to understand the relationship between the natural regeneration and the micro-environment of the endangered species Phoebe bournei seedlings; The research object is the regeneration individuals of Phoebe bournei natural forest with DBH<5.0 cm in Bangbei Village, Fuchuan County, Guangxi. Based on survey data of 0.64 hm2 fixed monitoring sample plots, Pearson correlation coefficient, redundancy analysis and other methods were used to analyze the relationship between seedling regeneration density and micro-environment factors of the sample plot. The results show that: (1) The largest number of small seedling recruit individuals of Phoebe bournei, the density decreased with the increase of age; Low transformation rate from seedlings to saplings, and the transformation rate from small seedlings to medium seedlings is the key stage of successful regeneration of Phoebe bournei; (2) The seedling regeneration density of Phoebe bournei was significantly positively correlated with the shrub height, the distance from the nearest parent tree, and the shrub coverage of the plot, while it was significantly negatively correlated with the light intensity and the herb layer coverage of the plot; (3) Through redundancy analysis, it can be seen that the key factors affecting the regeneration of Phoebe bournei seedlings are shrub height, the distance from the nearest parent tree, shrub coverage, the leaf area index, light, herb coverage, litter thickness, and soil salinity. Light and herb coverage are the limiting factors for the regeneration of seedlings. Therefore, reducing the light intensity, reducing herb coverage, and enhancing shrub coverage are conducive to the regeneration and development of population.