melanosporum brules contain a constant mixture of horizons due to the continuous digging that the harvesters, their dogs, and wildlife engage in to extract the ascocarps.
Macroscopic studies of the characteristics of the ascocarps, and microscopic studies of the morphological characteristics of the ascospores and mycorrhizas, permitted a clear identification of Tuber species located in the brules studied.
rufum ascocarps have been collected in soils with a greater concentration of TOC and total carbonate than T.
Garcia-Montero LG, Diaz P, Martin-Fernandez S, Casermeiro MA (2008) Soil factors that favour the production of Tuber melanosporum ascocarps over other truffle species: a multivariate statistical approach.
2006, 2007a, 2007b) report that the annual ascocarp production of Tuber melanosporum increases with the size of the brule, which explains 38% of the variance in its productivity; they also indicate that a high content of active carbonate (calcium carbonate extractable with ammonium oxalate) accounts for up to 51% of the variance in T.
Garcia-Montero LG, Casermeiro MA, Hernando I, Hernando J (2007a) Effect of active carbonate, exchangeable calcium, and stoniness of soil on Tuber melanosporum ascocarp production.