Data from: Phylogenetic signal in diatom ecology: perspectives for aquatic ecosystems biomonitoring

Diatoms include a great diversity of taxa and are recognized as powerful bioindicators in rivers. However using diatoms for monitoring programs is costly and time consuming because most of the methodologies necessitate species-level identification. This raises the question of the optimal tradeoff between taxonomic resolution and bioassessment quality. Phylogenetic tools may form the bases of new more efficient approaches for biomonitoring if relationships between ecology and phylogeny can be demonstrated. We estimated the ecological optima of 127 diatom species for 19 environmental parameters using count data from 2119 diatom communities sampled during 8 years in eastern France. Using uni- and multivariate analyses, we explored the relationships between freshwater diatom phylogeny and ecology (i.e. the phylogenetic signal). We found a significant phylogenetic signal for many of the ecological optima that were tested, but the strength of the signal varied significantly from one trait to another. Multivariate analysis also showed that the multidimensional ecological niche of diatoms can be strongly related to phylogeny. The presence of clades containing species that exhibit homogeneous ecology suggests that phylogenetic information can be useful for aquatic biomonitoring. This study highlights the presence of significant patterns of ecological optima for freshwater diatoms in relation to their phylogeny. These results suggest the presence of a signal above the species level, which is encouraging for the development of simplified methods for biomonitoring survey.硅藻类群多样性极高，被公认为河流生态系统中极具效力的生物指示物（bioindicators）。然而，将硅藻应用于环境监测项目往往成本高昂且耗时耗力，这是因为绝大多数检测方法均要求开展物种水平的鉴定。这一现状引出了分类分辨率与生物评估质量间最优权衡的核心议题。若能证实生态学特征与系统发育（phylogeny）之间的关联，系统发育工具便可成为新一代更高效的水生生物监测方法的核心支撑。本研究依托法国东部地区8年间采集的2119个硅藻群落的计数数据，针对19项环境参数，估算了127个硅藻物种的生态最适值。通过单变量与多变量分析，本研究探究了淡水硅藻的系统发育与生态学特征之间的关联，即系统发育信号（phylogenetic signal）。研究发现，多数被测的生态最适值均存在显著的系统发育信号，但信号强度因性状不同而存在显著差异。多变量分析还表明，硅藻的多维生态位（ecological niche）与系统发育存在较强的相关性。包含生态学特征均一的物种的演化支（clades）的存在，提示系统发育信息可用于水生生物监测工作。本研究证实了淡水硅藻的生态最适值存在与其系统发育相关的显著模式。上述结果表明，物种水平之上的系统发育信号确实存在，这为开发简化的生物监测调查方法提供了有力支撑。