In the wine-making heart of the northern Rhone hills in southeastern France, one of Pierre-Jean Villa's plots is a curiosity.

In the wine-making heart of the northern Rhone hills in southeastern France, one of Pierre-Jean Villa's plots is a curiosity.

Winemakers across France are experimenting with the ancient practice of "vitiforestry" – growing trees alongside vines – to tackle the modern issue of climate change, and many are…