Forest damage in the Ore Mountains caused mainly by the air pollution, mainly sulphur dioxide, can be observed within the region from the late fifties. Northern Bohemia, where the Ore Mts. are situated, was the main source of the total amount of sulphur dioxide emissions (about 50%) in the Czech Republic during the last decades. The total sulphur dioxide emission has culminated in mid-eighties. From that time the concentrations of sulphur and partly also of other pollutants are permanently decreasing. However, simple lowering of the sulphur dioxide emissions does not mean automatically also the improvement of the forest ecosystem, even when it would be the only harmful agent. The stability of the forest ecosystem has been disturbed due to long-term effect of several destructive agents. Teh result of the negative impact of mainly silphur dioxide can be observed only after several years. Also the dynamics of the forest ecosystem reaction is usually slower than the dynamics of the environment changes. During the winter period of 1995/96 vast acute damage of forest stands in NE part of the Ore Mts. ridge have been caused by longt-term extreme rime, high SO2 concentrations, and unfavourable climatic conditions. This situation has confirmed that even comparatively low concentrations of sulphur dioxide emissions, when connected with some other negative factors, can be devastating for the forest ecosystems.
