ABSTRACT
The Massif Central is an upland area of igneous origin in southern France (Figure 23.1) with a mean elevation of 800 m, from 300 m in the Limagne plain to 1,886 m in the Sancy Mountains and covers about 70,000 km2 (12.7% of France). Only the higher elevations will be considered here, as the low fertile plains are farmed (Figure 23.2). The climate is semi-continental, with low winter temperatures (≥−20°C), late spring frosts (until June), and high summer temperatures (≤30°C). A striking feature of the climate is the high amplitude of daily temperature variation, sometimes more than 25°C. Temperatures vary with elevation, about −0.6°C per+100 m elevation (Guitton 1986). Rainfall is about 800 mm per year but varies widely with exposure, from less than 600 mm in the rain shadow of hills to more than 1,500 mm in the west slopes of the mountains. Rainfall is fairly evenly distributed throughout the year (Figure 23.3), especially in areas benefiting from oceanic influences, but summer droughts occur about one year in every five (Balandier et al. 2003a).
