Endangered delicacy: Italy's white truffles

White truffles are so valuable because they're extremely rare. They grow naturally in the earth in just a few regions of Italy and central Europe. The unique flavor and aroma of white truffles cannot be artificially reproduced. And, unlike varieties of black truffle, they cannot be cultivated.

What adds to the mystique of white truffles is how difficult it is to get a hold of them. White truffles can only be found from autumn until late February. And it's incredibly hard to spot them - only trained dogs can recognize their scent.

The Piedmont region in northwestern Italy is famous for its delicious white truffles. Also known as "white gold" or "white diamonds," the expensive mushrooms have an unmistakable earthy flavor. But white truffles are becoming even rarer, and may even be threatened with extinction.

Climate change plays a major role in endangering white truffles. Truffles need constant humidity during the summer - but the region's once well-distributed annual rainfall pattern has changed, and is now more extreme. Violent rainfall in November 2016 led to dangerous flooding.

Another factor affecting truffle production is the flourishing wine industry. Piedmont produces some of Italy's finest wines - such as Barolo, Nebbiolo and Dolcetto. In recent years, historic woodland areas have been cleared for new vines. What's needed to save the truffles is to maintain the biodiversity of the hills, allowing truffles to grow alongside vineyards, says naturalist Edmondo Bonelli.

Also the presence of nonnative, invasive species is helping push the white truffle to the brink. The American black locust, pictured above, pushes out native species, preventing them from flourishing. And the Chinese tree of heaven produces a toxin in its roots that acts as poison for the rare truffle.

In order to protect the world-famous luxury mushroom from extinction, a group of truffle lovers and environmentalists has launched a crowdfunding campaign. They aim to raise 50,000 euros ($54,000) by the end of the year to finance an ambitious environmental project to protect existing truffle-growing areas, and create new truffle beds.