The idea that forest trees can “talk” to each other, share resources with their seedlings—and even protect them—through a connective underground web of delicate fungal filaments is so intriguing, it’s taken root in popular media… but the science behind those ideas is unproven, cautions University of Alberta expert Justine Karst. In Nature Ecology & Evolution, Karst and two colleagues contest three claims about the capabilities of underground fungi known as CMNs. …While CMNs have been proven to exist, there is no strong evidence that they offer benefits to trees and their seedlings. …Karst and co-authors found that claims that CMNs are widespread in forests, isn’t supported by enough scientific evidence. …The claim that resources such as nutrients are transferred by adult trees to seedlings through CMNs and that they boost survival and growth, was found to be questionable. …The claim that adult trees preferentially send resources or “warning signals” of insect damage to young trees is not backed up by a single peer-reviewed, field study.
Additional coverage in Ole Miss – University of Mississippi News: Can Trees Communicate Underground? Maybe Not. UM biology professor debunks popular theory about soil fungal networks
Scientific American by Stephanie Pappas: Do Trees Really Support Each Other through a Network of Fungi? Not everyone is convinced.