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.

硅藻拥有极高的类群多样性，被公认为河流生态系统中极具应用价值的生物指示物（bioindicator）。然而，将硅藻用于生态监测项目往往成本高昂且耗时，这是因为绝大多数检测方法都要求开展物种水平的鉴定。这一问题引出了核心议题：如何在分类学分辨率与生物评估质量之间实现最优权衡。若能证实生态学特征与系统发育之间存在关联，系统发育分析工具便可为构建更高效的水生生物监测新方法奠定基础。本研究依托法国东部地区8年间采集的2119个硅藻群落计数数据，估算了127个硅藻物种针对19项环境参数的生态最适值。通过单变量与多变量分析方法，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，硅藻的多维生态位与系统发育存在较强的关联。存在包含生态特征均一物种的演化支这一现象，说明系统发育信息可应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与其系统发育之间存在显著关联模式。上述结果表明，该系统发育信号存在于物种水平之上，这为开发简化的生物监测调查方法提供了有力支撑。