Elevated atmospheric CO(2) concentration changes ectomycorrhizal morphotype assemblages in Betula papyrifera

Area of Science:

• Ecology
• Mycology
• Plant Science

Background:

• Ectomycorrhizae are symbiotic fungi crucial for tree health, offering diverse benefits.
• Fungal species exhibit varied physiologies and morphologies, influencing host plant interactions.
• Atmospheric CO2 levels are rising, potentially impacting forest ecosystems.

Purpose of the Study:

• To investigate how elevated atmospheric carbon dioxide (CO2) affects the composition of ectomycorrhizal fungal communities.
• To test the hypothesis that increased CO2 concentrations alter ectomycorrhizal assemblages associated with trees.

Main Methods:

• Examined ectomycorrhizal morphotypes colonizing the roots of paper birch (Betula papyrifera) saplings.
• Saplings were grown under ambient or elevated (700 ppm) CO2 concentrations for 24 weeks.
• Quantified the number and frequency of different ectomycorrhizal morphotypes.

Main Results:

• Elevated CO2 significantly altered the ectomycorrhizal community composition.
• A shift towards morphotypes with more emanating hyphae and rhizomorphs was observed under elevated CO2.
• These changes indicate a potential for increased mycorrhizal investment by the host plant.

Conclusions:

• Paper birch saplings adapt their ectomycorrhizal associations in response to elevated CO2.
• Future high-CO2 environments may favor ectomycorrhizal fungi with more extensive structures.
• This suggests enhanced mycorrhization capacity for trees in a changing climate.