首页 > 分享 > 附生维管植物多样性及其与宿主特征的相关性: 以哀牢山中山湿性常绿阔叶林为例

附生维管植物多样性及其与宿主特征的相关性: 以哀牢山中山湿性常绿阔叶林为例

花匠小妙招
2025-01-11 11:18

摘要：

附生维管植物对维持森林生态系统的生物多样性、碳储量、生态水文和养分通量有重要贡献。评估附生植物的多样性格局可以为其群落构建机制以及全球变化背景下附生植物的保护和资源利用提供依据。本文以哀牢山中山湿性常绿阔叶林1.44 ha塔吊样地中的附生维管植物为研究对象, 综合分析了6种优势乔木宿主植株上附生维管植物的物种丰富度(S)、系统发育多样性(PD)、系统发育结构及其与宿主胸径、树高和物种的相关性。结果表明: 哀牢山中山湿性常绿阔叶林311株优势乔木上共调查到26科44属62种附生维管植物。附生植物物种丰富度和系统发育多样性与宿主胸径和树高均呈极显著正相关(P < 0.001)。标准化的系统发育多样性(SES.PD)与附生植物物种丰富度无显著相关关系, 随宿主胸径的增加而显著增加(P < 0.05), 随宿主树高的增加而显著减小(P < 0.05)。折柄茶(Stewartia pteropetiolata)上附生植物的物种丰富度与PD极显著低于其他宿主物种(P < 0.001), 但6种宿主物种上附生植物的SES.PD无显著差异(P > 0.05)。变色锥(Castanopsis wattii)和多花含笑(Michelia floribunda)上的附生植物系统发育结构呈发散状态, 木果柯(Lithocarpus xylocarpus)和折柄茶上的附生植物系统发育结构呈聚集状态, 其余宿主上的附生植物系统发育结构不明显。综上所述, 宿主特征包括宿主大小和物种的差异是维持附生维管植物多样性格局的关键, 这一结果可为今后从多维度、多角度解析附生维管植物多样性的格局及其维持机制奠定坚实基础。

关键词: 附生植物, 生物多样性, 系统发育, 宿主大小, 林冠塔吊, 亚热带森林

Abstract

Aims: Vascular epiphytes have a significant contribution to maintaining biodiversity, carbon storage, ecological hydrology and nutrient flux in a forest ecosystem. Assessing the diversity pattern of epiphytes thus can provide a basis for community assembly mechanism, conservation and resource utilization of epiphytes in the context of global change. In this context, we aimed to analyze the species and phylogenetic diversity including the phylogenetic structure of vascular epiphytes, and their correlations with host characteristics in the subtropical evergreen broad-leaved forest in the Ailao Mountains, Southwest China.

Methods: Using a built-in canopy crane, we observed 311 individuals of dominant host trees in the 1.44 ha permanent plot and recorded the occurrence of vascular epiphytes including host tree identity, diameter at breast height (DBH) and tree height. Afterward, species richness (S), phylogenetic diversity (PD) and phylogenetic structure (net nearest taxa index (NTI) and net relatedness index (NRI)) of vascular epiphytes and their correlation with DBH, height and species of host trees were evaluated.

Results: A total of 62 species of vascular epiphytes belonging to 26 families and 44 genera were found. Remarkably, significant positive correlations were found between the epiphyte species richness and PD with the host DBH and height (P < 0.001). No significant correlations were detected between standard phylogenetic diversity (SES.PD) and species richness. The species richness and PD of epiphytes in Stewartia pteropetiolata were significantly lower than in other host species (P < 0.001). However, SES.PD significantly increased with the increase in host DBH (P < 0.05) and decreased with the increase in host height (P < 0.05). The phylogenetic structures of epiphytes on the Castanopsis wattii and Michelia floribunda were divergent, while epiphytes on the Lithocarpus xylocarpus and Stewartia pteropetiolata were clustered. Epiphytes on the other host trees did not show any phylogenetic structural pattern.

Conclusion: Host tree characteristics, including host size and host species differences, are the key factors that maintain the diversity pattern of vascular epiphytes. These results can provide a solid foundation for future analysis of the pattern and maintenance mechanism of epiphyte diversity from multiple dimensions and perspectives.

Key words: epiphytes, biodiversity, phylogeny, host size, canopy crane, subtropical forest