Abstract: Fire is one of major factors in forest ecosystem. This paper presents results of charcoal and pollen analysis on Early Holocene sediments in Lake Barrine, Australia. Time series analysis and mathematical modeling were used to infer patterns of forest fire, relationship between fire and major vegetation elements and the roles forest fire played in forest changes. The analysis shows that in Early Holocene fire frequencies in this area decreased from one major fire in less than 50 years in the early Eucalyptus forest stage (zone S1) to one in 230 years in the later stage (zone S2). After the establishment of rainforest, fire activities were much weaker. The effects of fire on three major elements of Eucalyptus forest varied according to their different fire adaptive traits. In process of the change from Eucalyptus, forest to rainforest, fire protected-the former and delayed.the establishment of the later.

Key words: Forest ecology, Fire, Charcoal, Pollen analysis