Potholes - USPOT002 Heyerdahl, Emily K.; Falk, Donald A.; Loehman, Rachel A. Dating method: crossdated Sample storage location: USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, 5775 US W Highway 10, Missoula, MT 59808, Emily K. Heyerdahl (eheyerdahl@fs.fed.us, 406-829-6939) Reference: Heyerdahl, E.K., R.A. Loehman, D.A. Falk 2014. Mixed-severity fire in lodgepole-dominated forests: Are historical regimes sustainable on Oregon's Pumice Plateau, USA?. Canadian Journal of Forest Research. 44:593–603. DOI doi 10.1139/cjfr-2013-0413. Abstract: In parts of central Oregon, coarse-textured pumice substrates limit forest composition to low-density lodgepole pine (Pinus contorta Douglas ex Loudon var. latifolia Engelm. ex S. Watson) with scattered ponderosa pine (Pinus ponderosa Lawson & C. Lawson) and a shrub understory dominated by antelope bitterbrush (Purshia tridentata (Pursh) DC.). We reconstructed the historical fire regime from tree rings and simulated fire behavior over 783 hectares of this forest type. For centuries (1650-1900), extensive mixed-severity fires occurred every 26 to 82 years, creating a multi-aged forest and shrub mosaic. Simulation modeling suggests that the historical mix of surface and passive crown fire were primarily driven by shrub biomass and wind speed. However, a century of fire exclusion has reduced the potential for the high-severity patches of fire that were common historically, likely by reducing bitterbrush cover, the primary ladder fuel. This reduced shrub cover is likely to persist until fire or insects create new canopy gaps. Crown fire potential may increase even with current fuel loadings if the climate predicted for mid-century lowers fuel moistures, but only under rare extreme winds. This study expands our emerging understanding of complexity in the disturbance dynamics of lodgepole pine across its broad North American range. Establishment data from this site are available at: http://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/establishment/northamerica/uspot002.dat NOAA/IMPD web landing page for this fire history site is available at: http://ncdc.noaa.gov/paleo/study/18097 FHX filename: uspot002.fhx IMPD code: USPOT002 Name of site: Potholes Site code: POT Contributors: Heyerdahl, Emily K.; Falk, Donald A.; Loehman, Rachel A. Latitude: 43.730972 (WGS84) Longitude: -120.942639 (WGS84) Mean elevation: 1486 (meters) Country: United States State: Oregon Region: central Oregon First year: 1490 AD Last year: 2009 AD Species name : Pinus ponderosa [PIPO], Pinus contorta Douglas ex Loudon [PICO] Common name : ponderosa pine, lodgepole pine Funding agency names and grant numbers: National Fire Plan, Rocky Mountain Research Station, Central Oregon Fire Management Service (Deschutes and Ochoco National Forests, Crooked River National Grassland, and Prineville District Bureau of Land Management), Forest Service Region 6, The Nature Conservancy, and The University of Arizona Comments: This site was sampled as part of a project to reconstruct historical fire regimes in central Oregon. Ring-boundary fire scars were assigned to the preceding calendar year. Several metadata files are provided with the FHX file. -999 in any file indicates no data. Ring-boundary fire scars were assigned to the preceding calendar year. Several metadata files are provided with the FHX file. -999 in any file indicates no data. Four supplemental information files are located at URL - http://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/northamerica/supplemental/ : (1) uspot002-plot-data.csv provides information on the plots. (2) uspot002-saplings.csv provides information on small trees that we did not attempt to remove wood samples from. These trees were tallied in each plot by species and diameter class (measured at breast height, 1.4 m) in 5.6-m radius plots. Diameter classes: 2.5 (0-5 cm), 7.5 (5-10 cm), 15 (10-20 cm). (3) uspot002-scarred-tree-info.csv provides information on fire-scarred trees, including ones we also sampled for recruitment date. (4) uspot002-undatable-trees.csv provides information on trees from which it did not appear that we could obtain intact wood samples. Fire History Graphs: Fire History Graphs illustrate specific years when fires occurred and how many trees were scarred. They are available in both PDF and PNG formats. The graphs consist of 2 parts, both of which show the X axis (time line) at the bottom with the earliest year of information on the left and the latest on the right. The Fire Index Plot is the topmost plot, and shows two variables: sample depth (the number of recording trees in each year) as a blue line along the left Y axis, compared with the percent trees scarred shown as gray bars along the right Y axis. Below, the Fire Chronology Plot consists of horizontal lines representing injuries by year on individual sampled trees. Symbols are overlain that denote the years containing the dendrochronologically-dated fire scars or injuries. The sample ID of each tree is displayed to the right of each line. The Composite Axis below represents the composite information from all individual series. The symbols used to represent the fire scars or injuries, and the filters used to determine the composite information, are shown in the legend. These graphs were created using the Fire History Analysis and Exploration System (FHAES). See https://www.frames.gov/partner-sites/fhaes/fhaes-home/ for more information.