A starting guide to root ecology: Strengthening ecological concepts and standardizing root classification, sampling, processing and trait measurements

Authors: FRESCHET, GREGOIRE - National Council For Scientific Research-Cnrs; PAGÈS, LOIC - Institut National De La Recherche Agronomique (INRA); IVERSEN, COLLEEN - Oak Ridge National Laboratory; Comas, Louise; REWALD, BORIS - University Of Natural Resources & Applied Life Sciences - Austria

Submitted to: HAL
Publication Type: Pre-print Publication
Publication Acceptance Date: 8/21/2020
Publication Date: 8/21/2020
Citation: Freschet, G., Pagès, L., Iversen, C., Comas, L.H., Rewald, B. 2020. A starting guide to root ecology: Strengthening ecological concepts and standardizing root classification, sampling, processing and trait measurements. HAL. 2020. hal-02918834

Interpretive Summary: More information on the belowground components in plant and ecosystem studies has been consistently called for in recent decades, but types of data and the methodology in collecting them has been variable among studies. This collection of root traits and methods, put together with the collective effort of a large team of experts, is to be used not only as starting point by students and scientists who desire working on belowground ecosystems but also by confirmed experts for consolidating and broadening their views on plant root measurements. In addition to compiling measurement protocols, we have synthesized the literature from root biology to provide key background useful for (i) defining root system components, (ii) considering root traits to measure to capture specific functioning, (iii) considering methodological steps for root handling, processing and storage, and (iv) gathering of meta-data necessary for the interpretation of results and their re-use. Importantly, all root traits presented have been introduced along a foundation for understanding their ecological meaning, their typical use, and some methodological and conceptual perspectives for future research.

Technical Abstract: In the context of a recent massive increase into research on plant root functions and their impact on the environment, root ecologists currently face many important challenges to keep on producing cutting edge, meaningful and integrated knowledge. Consideration of the belowground components in plant and ecosystem studies has been consistently called for in recent decades, but methodology is disparate and sometimes inappropriate. This handbook, based on the collective effort of a large team of experts, is to be used not only as starting point by students and scientists who desire working on belowground ecosystems but also by confirmed experts for consolidating and broadening their views on root ecology. Beyond the classical compilation of measurement protocols, we have synthesized recommendations from the literature to provide key background knowledge useful for (i) defining belowground entities and giving keys for their meaningful dissection, classification and naming beyond the classical fineversus coarse-root approach, (ii) considering the specificity of root research to produce sound laboratory and field data, (iii) describing typical but overlooked steps for studying roots, e.g. root handling, cleansing and storage, and (iv) gathering of meta-data necessary for the interpretation of results and their re-use. Most importantly, all root traits have been introduced with some degree of ecological context that will be a foundation for understanding their ecological meaning, their typical use and uncertainties, and some methodological and conceptual perspectives for future research. Considering all of this, we urge readers to not solely extract protocol recommendations for trait measurements from this monograph, but take a moment to sit down, read and reflect on the extensive information contained in this broader guide to root ecology, including parts I to VII and the many introductions to each section and root trait description. Finally, it is critical to understand that a major aim of this guide is to help break down barriers between the many subdisciplines of root ecology and ecophysiology, broaden researchers’ views on the multiple aspects of root study and create favourable conditions for the inception of comprehensive experiments on the role of roots in plant and ecosystem functioning.