We examined the expansion of Amanita muscaria into native protected Nothofagaceae
forests of Patagonian Argentina and documented its occurrence in pure stands of Nothofagus
dombeyi and Lophozonia alpina. We confirmed the ectomycorrhizal association between
A. muscaria and L. alpina root tips, representing the first verified record of this
symbiosis in Patagonia. We provided detailed morphological descriptions of the ectomycorrhizas
formed with N. dombeyi and L. alpina and compared them with those formed with the
most planted Pinus spp. These descriptions revealed diagnostic traits that allowed
us to reliably distinguish the new associations from previously known A. muscaria
morphotypes. Our results support the use of ectomycorrhizal morphotyping as a low-cost
and practical tool for monitoring invaded stands and for evaluating the impact and
effectiveness of forest management interventions across these native forests.
