Fig. 2

Diagram of the fire history of Catoctin Mountain Park, Maryland, USA, from 1652 to 2018, created from data collected in our fire history study in 2018. Each horizontal line represents the years covered by an individual tree sample (three-digit number starting with CAT, given at right), while vertical tick marks indicate fire years and vertical rectangles indicate injuries. Slanted lines at the beginning or end of a sample represent missing pith or bark, whereas a vertical line represents intact pith or bark. The composite timeline at the bottom shows the dates of fires that scared at least two trees in the same year. In the graph at the top, the blue line indicates the sample depth (number of samples that cover any given year), while the vertical black lines represent the percentage of our samples that were scarred in that year