Altered root traits due to elevated CO2: a meta-analysis

Ming Nie*, Meng Lu, Jennifer Bell, Swastika Raut, Elise Pendall

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

155 Citations (Scopus)


Aim Plant root traits regulate belowground C inputs, soil nutrient and water uptake, and play critical roles in determining sustainable plant production and consequences for ecosystem C storage. However, the effects of elevated CO2 on root morphology and function have not been well quantified. We reveal general patterns of root trait responses to elevated CO2 from field manipulative experiments.

Location North America, Europe, Oceania, Asia.

Methods The meta-analysis approach was used to examine the effects of CO2 elevation on 17 variables associated with root morphology, biomass size and distribution, C and N concentrations and pools, turnover and fungal colonization from 110 published studies.

Results Elevated CO2 increased root length (+26.0%) and diameter (+8.4%). Elevated CO2 also stimulated total root (+28.8%), fine root (+27.7%) and coarse root biomass (+25.3%), demonstrating strong responses of root morphology and biomass. Elevated CO2 increased the root:shoot ratio (+8.5%) and decreased the proportion of roots in the topsoil (-8.4%), suggesting that plants expand rooting systems. In addition, elevated CO2 decreased N concentration (-7.1%), but did not affect C concentration, and thus increased the C:N ratio (+7.8%). Root C (+29.3%) increased disproportionately relative to root N pools (+9.4%) under elevated CO2. Functional traits were also strongly affected by elevated CO2, which increased respiration (+58.9%), rhizodeposition (+37.9%) and fungal colonization (+3.3%).

Main conclusions These results suggest that elevated CO2 promoted root morphological development, root system expansion and C input to soils, implying that the sensitive responses of root morphology and function to elevated CO2 would increase long-term belowground C sequestration.

Original languageEnglish
Pages (from-to)1095-1105
Number of pages11
JournalGlobal Ecology and Biogeography
Issue number10
Early online date17 Apr 2013
Publication statusPublished - Oct 2013


  • C sequestration
  • CO2
  • free-air CO2 enrichment
  • meta-analysis
  • open top chamber
  • plant root
  • atmospheric carbon-dioxide
  • fine roots
  • deciduous forest
  • enrichment face
  • loblolly-pine
  • soil-microorganisms
  • N availability
  • responses
  • nitrogen
  • dynamics


Dive into the research topics of 'Altered root traits due to elevated CO2: a meta-analysis'. Together they form a unique fingerprint.

Cite this