A 750-YEAR FIRE HISTORY BASED ON LAKE SEDIMENT RECORDS IN CENTRAL YELLOWSTONE-NATIONAL-PARK, USA

A 750-year fire history was reconstructed for the Central Plateau of Y ellowstone National Park from the deep-water sediments of five lakes. The charcoal record from a large lake provided a chronology of regiona l fires. Data from four small lakes were used to study local and extra local fires. The co-occurrence of abundant charcoal and high magnetic- susceptibility values at the same stratigraphic level was used as evid ence of a local catchment fire, and a charcoal peak without high magne tic susceptibility was ascribed to an extralocal fire or a local fire without a related erosion event. The fire history was compared with th e dendrochronologic fire record for the last 450 years, and the close agreement provided the justification to extend the chronology back in time. Large areas of the region burned in AD 1988, c. 1700, c. 1560, a nd c. 1440. From c. 1220 to 1440 and c. 1700 to 1987, intermediate to small areas burned. The near-absence of fires in the twentieth century prior to the large fires of 1988 is evident in the charcoal record.