Figure 7

Relationship between fire occurrence and reconstructed temperature and precipitation for ponderosa pine and grand fir sites in the Blue Mountains of the Malheur National Forest, Oregon, USA. Top panels show annual precipitation and temperature reconstructions between 1706 and 1900 as small hash marks on the y-axis and x-axis, respectively (fire histories were reconstructed to 1650, but precipitation reconstructions only extend to 1706). The position of points on the y-axis and x-axis correspond to the reconstructed precipitation and temperature value in a year in which fire was recorded in a ponderosa pine (orange point) or grand fir (green point) site. The bottom panels show the density of years in fire was recorded in ponderosa pine (lower left) and grand fir (lower right) sites.