In Switzerland most of the forest fires occur in the southern part, a small region of 397,000 ha with 44% forest cover (176,000 ha). During the period 1973-1992, 60% (1,840) of all wildfires recorded in Switzerland occurred in this region, covering 88% (16,375 ha) of the total burnt surface. The highest frequency of fires in the southern Alps is recorded in winter and spring along the colline-submontaneous belt between 200 and 1000 m a.s.l. (chestnut forest belt). During the dormant period, high loads of highly flammable downed woody fuels and meteorological conditions (low precipitation, north wind, low relative humidity) favour the start and spread of forest fires. The causes of these fires are all anthropogenic. Natural fires are less important and are caused by lightnilg in summer (July, August).