Ectomycorrhizal community dynamics of Pinaceae invasions in Patagonian Nothofagus forests

NUÑEZ MARTIN A; POLICELLI NAHUEL; MUJIC ALIJA BAJRO; SMITH MATTHEW E.

Athens, Georgia

Congreso; 85th Meeting of the Mycological Society of America ?Translational Mycology: Putting Fungal Diversity to Work?; 2017

Mycological Society of America

Nothofagus species are the only widespread ectomycorrhizal (ECM) host trees native to Southern South America (SSA). Invasion of ECM Pinaceae that are native to Western North America is a growing problem in the area and represents a threat to the biological diversity and stability of Nothofagus forests. Recent research has demonstrated that Pinaceae invasions in SSA are facilitated by a community of exotic co-invasive ECM fungi. Given the evolutionary isolation of Nothofagus species and their associated ECM fungi in SSA, the introduction of invasive ECM taxa may have unpredictable effects upon the structure and composition of native Nothofagus ECM fungal communities. To address this concern, we sequenced the ITS1 region of all fungi in the rhizosphere of Nothofagus antarctica and Nothofagus dombeyi within invaded sites and along a spatial gradient extending into adjacent Nothofagus stands without Pinaceae. The native fungal community of the Nothofagus rhizosphere was dominated in all treatments by non-mycorrhizal Mortierella species and while the prevalence of these species is unaffected by invasion of Pseudotsuga menziesii, they show reduced abundance where Nothofagus antarctica is invaded by Pinus contorta. Invasion of both Pseudotsuga menziesii and Pinus contorta into Nothofagus stands alters native ECM community composition and Pinus contorta also reduces native Nothofagus antarctica ECM species richness. This study presents the first metagenomic data that details the response of native Nothofagus ECM fungal communities in SSA to co-invasion of Pinaceae trees and their fungal symbionts.