Ancient Fires on Southern Vancouver Island, British Columbia, Canada: A Change in Causal Mechanisms at about 2,000 ybp

Charcoal records were examined from seven sediment cores and two stratigraphic sections on southern Vancouver Island, Canada. Charcoal influx and climate trend regressions were established using high order polynomial functions. During the late-glacial (ca. 13,000–10,000 ybp), variations in the charcoal record suggest that fires likely responded to changes in fuel availability and climate. The high incidence of early-Holocene (ca. 10,000–7,000ybp) fires may have been partly modified by human activity, though it seems more likely that climate exerted the greatest control. A decrease in fires during the mid- and early late-Holocene from 7,000–4,000 and 4,000–2,000 ybp respectively is consistent with a regional moistening trend, implying that fires were climatically limited. In the late late-Holocene from 2,000 ybp–present, several sites record an increase in charcoal influx even though climate was continuing to moisten and cool, suggesting that non-climatic factors were responsible for the observed increase in fire activity. Estimates of native populations range up to thousands of people for southern Vancouver Island before the arrival of Europeans. These people were knowledgeable of fire, suggesting that humans were responsible for the increase in fires during the late late-Holocene cool, moist interval.