Despite its status as a highly-prized and coveted fungi in gastronomy, many aspects of the subterranean life cycle of the Burgundy truffle (Tuber aestivum) are still unknown, because in situ observations of the formation and maturation of truffle fruitbodies remain difficult. Here, we adopted a suite of archaeological fine-scale excavating techniques to provide unique spatiotemporal snapshots of Burgundy truffle growth at three sites in southern Germany. We also recorded the relative position, fresh weight, maturity level and genotype composition of all excavated fruitbodies. Varying by a factor of thousand, the fresh weight of 73 truffle ranged from 0.1 to 103.2 g, with individual maturity levels likely representing different life cycle stages from completely unripe to fully ripe and even decaying. While only a slightly positive relationship between fruitbody weight and maturity level was found, our results suggest that genetically distinct specimens can exhibit different life cycle stages at the same period of time and under the same environmental conditions. We therefore argue that truffles are likely able to grow, mature and ripe simultaneously between early summer and late winter of the following year. Our case study should encourage further eco-archaeological truffle excavations under different biogeographic settings and at different seasons of the year to gain deeper insights into the fungi's subterranean ecology. The expected cross-disciplinary findings will help truffle hunters and farmers to improve their harvest practices and management strategies.

Archaeological Heritage Office Saxony 01109 Dresden Germany

Chair of Forest Growth and Dendroecology University of Freiburg 79106 Freiburg i Br Germany

Department of Geography University of Cambridge Cambridge CB2 3EN UK

Department of Geography University of Cambridge Cambridge CB2 3EN UK; Global Change Research Institute of the Czech Academy of Sciences 8903 Birmensdorf Switzerland

Deutsche Trüffelbäume 78315 Radolfzell Germany

Global Change Research Institute of the Czech Academy of Sciences 603 00 Brno Czech Republic; Department of Geography Faculty of Science Masaryk University 611 37 Brno Czech Republic

Swiss Federal Research Institute 8903 Birmensdorf Switzerland

References provided by Crossref.org

Sustainable cultivation of the white truffle (Tuber magnatum) requires ecological understanding