The warm Mediterranean climate influences the region. However, 400 metres above sea level tempers the heat, bringing cool nights, which impart natural acidity to the grapes. The Mistral winds breeze through the vineyards, helping to keep the vines healthy. These conditions are favourable for sustainable viticultural practices which respect the environment and biodiversity. Treatments are conventional but minimal and mostly copper. The remarkable variation in terroirs enables the varieties to thrive in a particular soil type, with Syrah and Grenache flourishing in soils distinguished by the round pebbles in plots bordering the Rhone River and on the karst limestone of the Plateau des Gras, which forms the AOC Cotes du Vivarais. The AOC specifies how the vines are cultivated; the Guyot pruning method is forbidden, instead Cordon de Royat is preferred, along with foliage wires. Old Grenache vines are pruned into Gobelet bush vines. The vines are planted at a density of 4,000 per hectare, and the grapes are hand-harvested at dawn to preserve their freshness.