| Fig. 2. Fire-scar chronology for Monument Canyon Research Natural Area. The horizontal lines represent the life spans of individual trees, while fire-scar events are shown by short vertical bars. The longer vertical lines at the bottom indicate the dates of fire events in which at least 10% of the sampled trees recorded a fire. Note the cessation of spreading fires after 1892. For additional information on the fire history of ponderosa pine forests and on the use of fire scars to date fires, see the U.S. Geological Survey Biological Resources Division LUHNA (Land Use History of North America) website at http://biology. usgs.gov/luhna/southwest/southwest.html. | |
