In Colombia the Eurasian fungus is expanding its range into native, tropical forests.

To meet a global demand for timber, tree plantations were established in South America during the first half of the 20th century. Extensive plantings of non-native species now are found in Brazil, Chile, Argentina, and Uruguay. In Colombia, miscellaneous plantations were established in the 1950s, during a period of intensive local logging, when policies to limit deforestation in native forests were established. One unforeseen consequence of planting non-native trees was the simultaneous introduction and subsequent persistence of ectomycorrhizal fungi. We sought to document the origins and spread of the introduced found in Colombian plantations of the Mexican species , North American species , and Australian species and . In Colombia, is establishing a novel association with native and has spread to local forests. According to a Bayesian phylogeny and haplotype analysis based on the nuclear rDNA internal transcribed spacer region ITS1-5.8-ITS2 (ITS barcode), individuals found in four exotic plant species, and those colonizing roots, have a Eurasian origin and belong to two Eurasian haplotypes. This is the first time the spread of an introduced mutualist fungus into native Colombian forests is reported. To arrest its spread, we suggest the use of local inocula made up of native fungi, instead of inocula of introduced fungi.