Sniffing for fungi: Use of a conservation dog uncovers high regional truffle diversity

Heather A Dawson, Jonathan L. Frank, Carolyn Delevich, Bitty A. Roy, Hilary Rose Dawson 

Hypogeous aromatic fungi (‘truffles’) contribute significantly to overall fungal diversity but are difficult to find using traditional survey methods because they fruit underground, leading to under-documentation and a lack of understanding of truffle ecology. Truffles evolved to emit strong aromatic compounds to attract mycophagists for spore dispersal, a trait that culinary truffle harvesters exploit using trained truffle dogs. We trained a conservation dog to recognize a broad range of truffle aromas across diverse fungal lineages to increase efficiency in finding these cryptic fungi. In this case-study, we demonstrate the value of using a ‘truffle diversity dog’ in the floristically diverse Cascade-Siskiyou National Monument (CSNM), located on the southwestern Oregon and northwestern California border, U.S.A. The dog uncovered high biodiversity in this region, locating 103 truffle species in 34 genera across 23 families. We found that this trained dog was particularly valuable for locating species that are visually difficult to distinguish from the substrate and species that produce few fruiting bodies. Fewer than half of the unique taxa matched public sequence records, and many are likely new to science. We found high species turnover between oak and conifer habitats, suggesting high host specificity in truffles. The wide range of fungal taxonomic diversity found in this study by a conservation dog demonstrates the value of training dogs to generalize to all types of truffle aroma, providing a promising method to efficiently describe understudied fungal biodiversity.