skip to main content


Title: Climate, soil and plant functional types as drivers of global fine-root trait variation

Ecosystem functioning relies heavily on below-ground processes, which are largely regulated by plant fine-roots and their functional traits. However, our knowledge of fine-root trait distribution relies to date on local- and regional-scale studies with limited numbers of species, growth forms and environmental variation. We compiled a world-wide fine-root trait dataset, featuring 1115 species from contrasting climatic areas, phylogeny and growth forms to test a series of hypotheses pertaining to the influence of plant functional types, soil and climate variables, and the degree of manipulation of plant growing conditions on species fine-root trait variation. Most particularly, we tested the competing hypotheses that fine-root traits typical of faster return on investment would be most strongly associated with conditions of limiting versus favourable soil resource availability. We accounted for both data source and species phylogenetic relatedness. We demonstrate that: (i) Climate conditions promoting soil fertility relate negatively to fine-root traits favouring fast soil resource acquisition, with a particularly strong positive effect of temperature on fine-root diameter and negative effect on specific root length (SRL), and a negative effect of rainfall on root nitrogen concentration; (ii) Soil bulk density strongly influences species fine-root morphology, by favouring thicker, denser fine-roots; (iii) Fine-roots from herbaceous speciesmore » are on average finer and have higher SRL than those of woody species, and N 2-fixing capacity positively relates to root nitrogen; and (iv) Plants growing in pots have higher SRL than those grown in the field. Synthesis. This study reveals both the large variation in fine-root traits encountered globally and the relevance of several key plant functional types and soil and climate variables for explaining a substantial part of this variation. Climate, particularly temperature, and plant functional types were the two strongest predictors of fine-root trait variation. High trait variation occurred at local scales, suggesting that wide-ranging below-ground resource economics strategies are viable within most climatic areas and soil conditions.« less
ORCiD logo [1] ;  [2] ;  [1] ;  [3] ;  [4] ;  [1] ;  [5] ;  [2] ;  [1] ; ORCiD logo [6] ;  [7] ;  [8] ;  [9] ;  [10] ;  [11] ;  [12] ;  [13] ;  [14] ;  [15] ;  [16] more »;  [17] ;  [18] ;  [19] ;  [20] ;  [21] ;  [22] ;  [23] ;  [1] « less
  1. Univ. de Montpellier (France). Centre d'Ecologie Fonctionnelle et Evolutive; Univ. Paul-Valery Montpellier (France)
  2. Kent State Univ., Kent, OH (United States). Dept. of Biological Sciences
  3. Jonah Ventures, Manhattan, KS (United States)
  4. Univ. of Minnesota, St. Paul, MN (United States). Dept. of Plant Biology
  5. Univ. de Montpellier (France). Centre d'Ecologie Fonctionnelle et Evolutive; Univ. Paul-Valery Montpellier (France); Centre de recherche de Toulouse, Castanet-Tolosan Cedex (France)
  6. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Climate Change Science Inst. and Environmental Sciences Division
  7. Univ. of Rennes, Rennes (France). ECOBIO Unit
  8. US Dept. of Agriculture (USDA)., Fort Collins, CO (United States). Agricultural Research Service (ARS), Water Management Research Unit
  9. Vrije Univ., Amsterdam (Netherlands). Systems Ecology, Dept. of Ecological Sciences
  10. Hangzhou Normal Univ., Hangzhou (China). Key Lab. of Hangzhou City for Ecosystem Protection and Restoration, College of Life and Environmental Sciences
  11. Chinese Academy of Sciences (CAS), Beijing (China). Key Lab. of Ecosystem Network Observation and Modeling, Inst. of Geographic Sciences and Natural Resources Research
  12. Univ. of Minnesota, St. Paul, MN (United States). Dept. of Ecology, Evolution and Behavior
  13. Landcare Research, Lincoln (New Zealand)
  14. Univ. of Quebec, Montreal, QC (Canada). Dept. des sciences biologiques
  15. Kyoto Univ. (Japan). Graduate School of Agriculture
  16. Moscow State Lomonosov Univ., Moscow (Russia). Dept. of Geobotany
  17. Institut National de la Recherche Agronomique (INRA), Clermont-Ferrand (France)
  18. Univ. of Minnesota, St. Paul, MN (United States). Dept. of Forest Resources; Western Sydney Univ., Penrith, NSW (Australia). Hawkesbury Inst. for the Environment
  19. Univ. de Cordoba (Spain). Area de Ecologia
  20. Norwegian Univ. of Science and Technology, Trondheim (Norway)
  21. Leiden Univ. (Netherlands). Conservation Biology Dept., Inst. of Environmental Sciences
  22. Western Sydney Univ., Penrith, NSW (Australia). Hawkesbury Inst. for the Environment
  23. Swedish Univ. of Agricultural Sciences (SLU), Umea (Sweden). Dept. of Forest Ecology and Management
Publication Date:
Grant/Contract Number:
AC05-00OR22725; 14-50-00029
Accepted Manuscript
Journal Name:
Journal of Ecology
Additional Journal Information:
Journal Volume: 105; Journal Issue: 5; Journal ID: ISSN 0022-0477
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); European Union (EU); Russian Science Foundation (RNF)
Country of Publication:
United States
54 ENVIRONMENTAL SCIENCES; climate; database; fine roots; functional biogeography; functional traits; N2-fixation; phylogeny; plant growth form; plant resource economics; soil properties
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1375087