Fire and forest histories of central Oregon from tree rings
Central Oregon currently lacks the site-specific fire and forest histories that are necessary for scientifically based land-management planning in the region.
For a region with such extensive fire-adapted ecosystems, surprisingly few fire and forest histories have been reconstructed from tree rings, and these only at stand scales and in only a few of the region's forest types. In addition, climate change is recognized by the chief of the Forest Service as one of three critical new resource issues for the 21st century (http://www.fs.fed.us/climatechange). Anticipating the effects of climate change on future fire requires that we understand the effects of climate variation on past fires. It also requires that we bridge the past, present, and future by identifying the climate drivers of 20th-century fires from written archival records, and using this information to project future fire regimes. Finally, there is an urgent need to collect tree-ring evidence of past fires because modern prescribed burning and extensive, severe wildfires are rapidly and permanently consuming this evidence.
In cooperation with the Central Oregon Fire Management Service (Deschutes and Ochoco National Forests and the Prineville District of the Bureau of Land Management) and The Nature Conservancy, we began reconstructing fire and forest histories from tree rings in central Oregon in the summer of 2009. .
GOALS AND OBJECTIVES 1. Reconstruct annually accurate multi-century fire and forest histories from tree rings sampled systematically at 7 sites (approximately 1200 ac (500 ha) each). Of these, 5 sites will span a range of forest types but be centered on mixed-conifer forests (2 sites on the east-slope of the Cascades and 3 sites in the Ochocos); 1 site will be dominated by western juniper; and 1 site by lodgepole pine. 2. Identify the climate drivers of past regional-fire years in central Oregon from our tree-ring data, and for modern regional-fire years from written archival records of fire. Use these calibrations to project future fire regimes using regional climate scenarios.
Image: Location of sites with tree-ring reconstructed fire histories.