Monitoring the fate of a 30-year-old truffle orchard in Burgundy: from Tuber melanosporum to Tuber aestivum

Truffles, i.e. tree root-associated fungal fruiting bodies, clearly range among the world's most exclusive delicacies. Despite the quite restricted natural geographic occurrence of one of the most renowned fungal species, namely Tuber melanosporum, the development of inoculation procedures in the late 1960s made it possible to enlarge its production area in different countries. This was achieved by planting orchards with host tree seedlings colonized by the fungus. In the present work, we investigate the behavior of one of the earliest T. melanosporum orchards planted in Burgundy (France) over a long-term scale (more than 30 years). A picture of the orchard evolution was obtained by recording truffle yields and fungal morphotypes over the seasons and relating them to host-tree development and climate data. The most relevant results include the time-delayed, but rather fast replacement of inoculated T. melanosporum by naturally occurring T. aestivum and the key role of climate in the inter-annual variability of truffle production.