Interrelationships Between Wild Boars (Sus scrofa) and Truffles

The European population of wild boars has increased considerably since the 1960s, leading to increased damage to agroecosystems. Their distribution coincides with the natural distribution of the most important commercial Tuber species. In this chapter, the truffle/wild boar interrelationships are discussed and include the importance of truffles in their diet, their role in spore dispersal, and their impact on cultivated truffières. Wild boars eat a wide variety of foods: plant matter, animals, fungi, bulbs, tubers, and roots. Analyses of their feces and stomach contents suggest they can be considered casual or opportunistic mycophagists, with fungal consumption simply dependent on the availability of other foods. The ingestion of hypogeous fungi is more frequent than that of epigeous mushrooms. Their rooting behavior primarily reduces plant cover and diversity, affects the first 15–70 cm of the litter layer, and can damage up to 80 % of the forest soil surface. Excavation may cause great economic losses to cultivated truffières, not only in terms of truffle predation but also through soil disturbance so that there can be significant increases in truffle production after fencing cultivated truffières damaged by wild boars. Because wild boars can move as much as 15 km in a day, they efficiently contribute to long-distance dispersal of truffle spores. Moreover, the action of the degradation of the digestive enzymes on asci and spore wall improves germination and the ability to form ectomycorrhizas and results in wild boars playing a pivotal role in truffle colonization of new habitats.