1. Accurate quantification of biodiversity can be demanding and expensive. Although environmental DNA (eDNA) metabarcoding can facilitate biodiversity assessments through non-invasive, cost-efficient and rapid surveys, the approach struggles to outperform traditional morphological approaches in providing reliable quantitative estimates for surveyed species (e.g. abundance and biomass).
2. We present an integrated methodology for improving biodiversity surveys that pairs eDNA metabarcoding with morphological data, following a series of taxonomic and geographical filters. We demonstrate its power by applying it to a new spatiotemporal dataset generated on an Iberian-wide distributed aquatic mesocosm infrastructure that spans a wide biogeographical gradient.
3. By building upon the strengths that these two approaches offer, our framework improved taxonomic resolution for 30% of the taxa and enabled species’ traits (e.g. body size) and abundance to be assigned to 85% of the taxa in hybrid datasets.
4. These results indicate that eDNA-based assessments can complement, but not always replace, conventional approaches. Integrating conventional and modern eDNA metabarcoding approaches, already available in the ecologist's toolbox, will greatly enhance biodiversity assessments.

中文翻译：

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微调生物多样性评估：将 eDNA 元条形码和形态学方法配对的框架

1. 生物多样性的准确量化可能要求高且成本高。尽管环境 DNA (eDNA) 元条形码可以通过非侵入性、具有成本效益和快速的调查促进生物多样性评估，但该方法在为被调查物种（例如丰度和生物量）提供可靠的定量估计方面难以胜过传统的形态学方法。
2. 我们提出了一种改进生物多样性调查的综合方法，该方法将 eDNA 元条形码与形态学数据配对，遵循一系列分类和地理过滤器。我们通过将其应用于跨越广泛的生物地理梯度的伊比利亚范围内的分布式水生中观基础设施生成的新时空数据集来展示其力量。
3. 通过建立在这两种方法提供的优势的基础上，我们的框架提高了 30% 的分类群的分类分辨率，并使物种的特征（例如体型）和丰度能够分配给混合数据集中 85% 的分类群。
4. 这些结果表明，基于 eDNA 的评估可以补充但并不总是取代传统方法。将生态学家工具箱中已有的传统和现代 eDNA 元条形码方法相结合，将大大加强生物多样性评估。