Data from: Reproductive traits as predictors of assembly chronosequence patterns in epiphyllous bryophyte metacommunities

1) Understanding the mechanisms underlying species assembly is a central focus of plant ecology and is crucial to revealing how plant communities are structured. However, the temporal limitations of most terrestrial plant communities preclude collection of species assembly data in a tractable time-frame. 2) The aim of this study is to investigate the importance of dispersal potential, as estimated by inter-specific variation in sexual and asexual expression, as a predictor of patch chronosequence assembly for epiphyllous (leaf-inhabiting) bryophytes. Secondarily, we investigate whether spatio-temporal patterns in patch turnover and compositional variation infer evidence of local (within-patch) population processes. The frequency and distribution of 55 epiphyllous bryophytes across five leaf age classes were studied on an understory shrub Piper grande (Piperaceae) in pre-montane Panamanian tropical forest. Logistical models were used to test whether inter-specific variation in dispersal-related life history traits predicts assembly order. Beta diversity and ordination analyses were employed to examine nestedness versus turnover, and probe for repeatable patterns in patch chronosequence assembly, respectively. 3) Our results emphasize the importance of dispersal potential on species assembly patterns as earlier arrivals exhibit greater probabilities of sexual and specialized asexual expression. High turnover coupled with temporal convergence in species composition also point to evidence of within-patch biotic filtering. 4) Synthesis: Epiphylls are locally diverse in humid tropical forests worldwide; however, the mechanisms which maintain their high local diversity are unknown. This study suggests that inter-specific variation in dispersal capacity in combination with diffuse indirect effects are the principal contributors to the high alpha-diversity of these ephemeral metacommunities.1) 理解物种组装（species assembly）的内在机制是植物生态学（plant ecology）的核心研究议题之一，对于揭示植物群落（plant communities）的构建规律至关重要。然而，多数陆地植物群落（terrestrial plant communities）存在时间维度上的局限，使得在可操作的时间框架（tractable time-frame）内收集物种组装数据变得难以实现。 2) 本研究旨在探究以物种间有性与无性繁殖表现（sexual and asexual expression）差异估算得到的扩散潜力（dispersal potential），作为叶附生苔藓植物（epiphyllous bryophytes）斑块时间序列（patch chronosequence）组装的预测因子的重要性。次要研究目标为：检验斑块周转（patch turnover）与组成变异（compositional variation）的时空格局（spatio-temporal patterns）是否能够推断局域（斑块内部）种群过程（local population processes）的相关证据。研究在巴拿马山地前带热带森林（pre-montane Panamanian tropical forest）中，以林下灌木大胡椒（Piper grande，胡椒科Piperaceae）为宿主，调查了55种叶附生苔藓植物在5个叶龄组中的出现频率与分布格局。采用逻辑斯蒂模型（logistical models）检验物种间与扩散相关的生活史性状（life history traits）差异是否能够预测物种组装顺序；分别运用β多样性（beta diversity）分析与排序分析（ordination analyses），考察斑块时间序列组装中的嵌套性（nestedness）与周转模式，并探究其可重复的组装格局。 3) 本研究结果强调了扩散潜力对物种组装格局的重要性：早期定殖的物种展现出更高的有性繁殖与特化无性繁殖概率。高斑块周转与物种组成的时间趋同现象，同样指向了斑块内部生物过滤（biotic filtering）存在的证据。 4) 综合分析：叶附生苔藓植物在全球湿润热带森林中具有较高的局域多样性；然而，维持其高局域多样性的机制仍未明确。本研究表明，物种间扩散能力的差异与弥散性间接效应的共同作用，是造就这些短命集合群落（ephemeral metacommunities）高α多样性（alpha-diversity）的核心驱动因素。