Conventional detection methodology is limiting our ability to understand the roles and functions of fine roots

Authors

  • Alain Pierret,

    Corresponding author
    1. INRA – Climat, Sol & Environnement, Domaine St Paul, Site Agroparc, 84914 Avignon cedex 9, France;
    2. Present address: IRD-IWMI-NAFRI, BP 06, Vientiane, Laos
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  • Christopher J. Moran,

    1. Centre for Water in the Minerals Industry, Sustainable Minerals Institute, University of Queensland, Brisbane 4072, Australia;
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  • Claude Doussan

    1. INRA – Climat, Sol & Environnement, Domaine St Paul, Site Agroparc, 84914 Avignon cedex 9, France;
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Author for correspondence: Alain Pierret Tel: +856 20 550 2680 Fax: +856 21 41 2993 Email: pierret@ird.fr; apierret@gmail.com

Summary

  • • We lack a thorough conceptual and functional understanding of fine roots. Studies that have focused on estimating the quantity of fine roots provide evidence that they dominate overall plant root length. We need a standard procedure to quantify root length/biomass that takes proper account of fine roots.
  • • Here we investigated the extent to which root length/biomass may be underestimated using conventional methodology, and examined the technical reasons that could explain such underestimation. Our discussion is based on original X-ray-based measurements and on a literature review spanning more than six decades.
  • • We present evidence that root-length recovery depends strongly on the observation scale/spatial resolution at which measurements are carried out; and that observation scales/resolutions adequate for fine root detection have an adverse impact on the processing times required to obtain precise estimates.
  • • We conclude that fine roots are the major component of root systems of most (if not all) annual and perennial plants. Hence plant root systems could be much longer, and probably include more biomass, than is widely accepted.

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