Ectomycorrhizal fungal inoculations in Patagonia: the past, the present and ideas for the future

For more than a century, foresters have understood the critical role of soil biota in the growth and survival of trees. Pinaceae trees are a clear example of this, where foresters used to transport potted trees instead of seeds to secure the survival and growth of the species. This method of soil inoculation enabled the successful introduction of numerous tree species globally, but inadvertently introduced some undesirable fungi. We examine the case of Isla Victoria, Patagonia, Argentina, the first attempt in southern South America to establish forestry with non-native trees, introducing over 100 species from every continent except Antarctica. Isla Victoria became the primary seedling source for Pinaceae commercial plantations in Patagonia, leading to the spread of both the trees and their associated mycorrhizal fungi from the island. Many of these introduced fungi are now recognized as highly invasive (mainly Suilloids), enabling tree invasions, a significant environmental concern that is growing with deep economic and environmental impacts. Based on current knowledge, we propose strategies for more effective and precise ectomycorrhizal inoculation of Pinaceae trees in areas lacking yet established plantations. We suggest a focus on fungal species with limited dispersal but high growth and health-promoting abilities for a more sustainable forestry.