Guided by the beam of a flashlight, Tino Marolo follows his dog Stella through the darkness of a Piedmont woodland, searching for one of Italy’s most prized culinary treasures hidden beneath the soil.

In the hills around Alba, home to the world’s most famous white truffles, hunters known as “trifolau” traditionally begin their season on Oct. 1. But increasingly, they are confronting a challenge above ground: climate change.

Months of heat and drought have raised concerns about the future of the prized white truffle, a fungus that depends on cool, moist soils and a delicate relationship with tree roots.

“The entire month of October was affected by the lack of rain in July and August and the high temperatures, so it was characterized by poor production and poor truffle shelf life,” said Antonio Degiacomi, president of Italy’s National Centre for Truffle Studies.

According to Degiacomi, dry and compacted soils have also produced smaller truffles this season.

The difficult harvest comes as Alba and the…