Mycorrhizal interactions alter plant carbon dioxide fertilization effect

November 01, 2016

A recent (July 2016) Science Research Report was highlighted in the Imperial College London News discussing the effects of mycorrhizal associations within elevated CO2 environments upon plant biomass.

Fig. 2. Overall effects of CO2 on plant biomass. (A to C) Effects on (A) total, (B) aboveground, and (C) belowground biomass for two types of mycorrhizal plants species (AM and ECM) in N-limited experiments (low N) or experiments that are unlikely N-limited (high N). Overall means and 95% confidence intervals are given; we interpret CO2 effects when the zero line is not crossed.

A recent (July 2016) Science Research Report was highlighted in the Imperial College London News discussing the effects of mycorrhizal associations within elevated CO₂ environments upon plant biomass. Climate change has increased CO₂ levels and currently plants are utilizing the elevated CO₂ decreasing the effects creating a “CO₂ fertilization effect”, however when looking to future impacts upon plants by climate change two hypotheses are considered: 1) plant biomass will be enhanced by the “CO₂ fertilization effect”, continuing to slightly decrease global impacts of climate change, 2) environmental nitrogen limitations will decrease the CO₂ fertilization effect, reducing plant CO₂ uptake. This study complied elevated carbon experiments from around the world to dissect these hypotheses in the light of mycorrhizal interactions and discovered a primary interaction between nitrogen level and mycorrhizal association in correlation with plant biomass. Overall, plants in elevated CO₂ experiments with ectomycorrhizal fungi (ECM) had larger biomass increases with high or low nitrogen levels, than plants with arbuscular mycorrhizal fungi (AMF) with low nitrogen treatments. Thus, the CO₂ fertilization effect from climate change may only pertain to plants with ECM associations in nitrogen limited areas, and these results should be considered when modeling effects of climate change upon global vegetation.

Source:

Dunning H. 2016. Plants’ ability to slow climate change depends on their fungi. Imperial College London. Accessed October, 19, 2016. Article.
Terrer, C., Vicca, S., Hungate, B. A., Phillips, R. P., Prentice, C. 2016. Mycorrhizal association as primary control of the CO₂ fertilization effect. Science. 353: 72-73.