Tuber borchiiis an edible ectomycorrhizal mushroom of considerable economic value. Its cultivation has become popular in recent years, but there are few studies on the factors affecting its productivity. In this work, the ascoma production and the ectomycorrhizal (ECM) community of aT. borchiiplantation, established in an intensive farming area where this truffle is not naturally present, were studied.Tuber borchiiproduction drastically declined from 2016 to 2021, and ascomata of otherTuberspecies (T. maculatumandT. rufum) were found from 2017. Molecular characterization of ectomycorrhizae carried out in 2016 identified 21 ECM fungal species, of whichT. maculatum(22%) andTomentella coerulea(19%) were the most abundant.Tuber borchiiectomycorrizae (16%) were almost entirely confined to the fruiting points. The diversity and structure of the ECM community onPinus pineawere significantly different from those observed on hardwood trees. The obtained results suggest thatT. maculatum(a native of the study site) tends to replaceT. borchiithrough a mechanism of competitive exclusion. AlthoughT. borchiicultivation is possible in suboptimal environments, particular care should be taken to limit competition with ECM fungi more suitable for local conditions.