RECONSTRUCTION OF STAND FLUCTUATIONS, SOI L DEVELOPMENT AND FIRE HISTORY OVER 7000 YEARS BP BY MEANS OF CHARCOAL ANALYSIS

Charcoal fragments were found in a podsolic soil profile in a slope ab ove Intragna, canton of Ticino, Switzerland. Through species and genus analysis as well as C-14 dating it was found that soil development am ounted to +/- 100 cm in about 7000 years. The appearance of chestnut-t rees (Castanea sativa) since the Roman epoch as revealed by pollen ana lysis corresponds to the charcoal of this species present in the upper layer down to a depth of 20 cm. This diagnosis suggests that the soil must have developed around 20 cm during approximately the last 2000 y ears. The coniferous part of the stand (Abies alba, Pinus sp.) which w as continuously present until 7000 BP disappeared before approximately 2000 BP. The mean fire interval (MFI) amounts to 1800 years disregard ing of the last two fires in 1945 and 1987. It is possible that some f ire events were overlooked. The human influence of the fire frequency is not apparent on this particular site, though regional traces of hum an activity have already been detected.