Bark beetle - A stress factor of spruce forests in the Bohemian Forest

Historical review of land use displays a long-time lasting human interferen ce in natural forests in Bohemian Forest, often resulting in evenly aged No rway spruce plantations, covering recently extended areas of forest stands. The study proves that bark beetle, Ips typographus (L.), who is usually a permanent component of forest ecosystems, can become a significant stress f actor in highly man-influenced forests. Forest status, resulting from image ry processed time series of satellite Landsat 5 TM data (1987-1998), docume nts rapid increase of heavily damaged and declined spruce class in the whol e region after 1992 (from 8% in 1992 to 16% in 1998). Even more dramatic si tuation occurred in the "Modrava" region, where the bark beetle outbreak af ter 1995 reached a scale of serious calamity (9% of highly damaged and decl ined spruce class in 1992, 24% in 1995, and 39% in 1998).