长白山阔叶红松林乔木幼苗组成及多度格局的影响因素

以长白山原始阔叶红松林样地为平台,以样方中胸径小于1 cm的乔木幼苗为研究对象,基于2018年两次的幼苗调查数据,利用广义线性混合模型分析影响群落乔木幼苗多度的生物邻体和生境因素。结果表明:该样地所有幼苗样方共调查到10064株乔木幼苗,累计17个物种,分属9科9属,水曲柳幼苗多度极高,在乔木树种幼苗中占优势地位;在群落水平,幼苗多度与异种大树效应、草本密度和林冠开阔度呈显著正相关,与草本盖度和土壤含水量呈显著负相关;在物种水平,水曲柳和紫椴幼苗多度的影响因素与群落水平筛选后的结果一致,红松幼苗多度与异种大树效应呈正相关,与同种大树效应及林冠开阔度呈负相关。该研究证实了生物邻体和生境因素共同影响幼苗多度格局,并且生物邻体和生境因素的相对重要性随幼苗物种种类不同而变化。

Influencing factors of composition and abundance pattern of tree seedlings in broad-leaved Korean pine (Pinus koraiensis) mixed forest, Changbai Mountain, China

This research aimed to understand the importance of biotic neighborhood and habitat factors for tree seedling abundance in broad-leaved Korean pine (Pinus koraiensis) mixed forest in the Changbai Mountain, northeastern China. We examined the relative effect of biotic neighborhood and habitat factors on seedling abundance by using generalized mixed linear model over 2 times. The results showed that a total of 10064 seedlings were investigated in all seedling plots of this site, belonging to 9 genera, 9 families, and 17 species. The abundance of Fraxinus mandschurica seedlings is extremely high, occupying an important position in the seedling composition. At the community level, heterospecfic adult effect, canopy openness, and herb density exhibited significantly positive effects on seedling abundance, while herb cover and soil moisture exhibited significantly negative effects on it. At the species level, the factors influenced the seedling abundance of Fraxinus mandschurica and Tilia amurensis were consistent with the results after screening at the community level. Heterospecfic adult effect exhibited significantly positive effects on Pinus koraiensis seedling abundance, but conspecific adult effect and canopy openness exhibited significantly negative effects on it. This study showed that biotic neighborhood and habitat factors together affected seedling abundance pattern, and the relative importance of biotic neighborhood and habitat factors varied among different seedling species.