Ectomycorrhizal community dynamics of Pinaceae invasions in Patagonian Nothofagus forests

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

Berkeley, California

Congreso; MEETING OF THE MYCOLOGICAL SOCIETY OF AMERICA 2016 ?Sequencing the fungal environment: from populations to communities?; 2016

Mycological Society of America

Nothofagus species are the only widespreadectomycorrhizal (ECM) host trees native to SouthernSouth America (SSA). Invasion of ECM Pinaceae,native to Western North America, is a growingproblem in the area and represents a threat to thebiological diversity and stability of Nothofagus forests.Recent research has characterized the community ofECM fungi colonizing the roots of invasive Pinaceaetrees in SSA and demonstrated that Pinaceae invasionsin this region are facilitated by a community of exoticco-invasive ECM fungi. Given the evolutionaryisolation of Nothofagus species and their associatedECM fungi in SSA, the introduction of invasive ECMtaxa may have many unpredictable effects upon thestructure and composition of native Nothofagus ECMfungal communities. To address this concern, we haveemployed a metagenomic approach to characterize thefungal communities associated with Nothofagusrhizosphere soil in sites with Pinaceae invasions.Pinaceae invasions of Nothofagus antarctica andNothofagus dombeyi forests were studied in the regionof San Carlos de Bariloche, Argentina. Nothofagusantarctica is typically present in xeric sites whereinvasions of Pinus contorta are common. Nothofagusdombeyi is associated with mesic sites that arecommonly invaded by Pseudotsuga menziesii. TheITS1 region was sequenced from all fungi in therhizosphere of Nothofagus species within invaded sitesand along a spatial gradient into adjacent, uninvaded,Nothofagus stands without Pinaceae. This studycharacterizes the community compositional responseof Nothofagus ECM fungi to Pinaceae invasions andhelps to inform conservation efforts in SSA. This isthe first data available detailing the response of nativeNothofagus ECM fungal communities in SSA to coinvasionof Pinaceae trees and their fungal symbionts.