Comparison of fire history estimates between open-scarred and intact Quercus douglasii

Fire scars in 181 scarred Quercus douglasii cross sections were dated from 2 different stands in the Sierra Nevada foothills, California. In the stand with no fires for the last 35 yr, open-scarred trees revealed a shorter fire history, 90% fewer fire dates, and a mean fire interval (MFI) that was shorter than determined from intact trees. In the stand with no fires for the last 15 yr, MFI and length and length of record were comparable but open-scarred trees accounted for 27% fewer fires than intact trees. Open-scarred trees were twice as likely to scar as intact trees, but the average number of scars tree^-1 were similar. Time since last fire is critical, as scars may heal before sampling. This suggests that fire history estimates will be most affected by sample restriction in areas with long periods of fire suppression. -from Author