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

作者：Nie Ming^*; Lu Meng; Bell Jennifer; Raut Swastika; Pendall Elise

来源：Global Ecology and Biogeography, 2013, 22(10): 1095-1105.

DOI：10.1111/geb.12062

• C sequestration
• CO2
• free-air CO2 enrichment
• meta-analysis
• open top chamber
• plant root

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. %26lt;br%26gt;Location North America, Europe, Oceania, Asia. %26lt;br%26gt;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. %26lt;br%26gt;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%). %26lt;br%26gt;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.

• 出版日期2013-10
• 单位复旦大学