Sierra Nevada Fire Severity Monitoring 1984-2004
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United States Department of Agriculture Sierra Nevada Forest Service Pacific Southwest Fire Severity Monitoring Region R5-TP-027 1984-2004 August 2008 The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410, or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. Sierra Nevada Fire Severity Monitoring 1984 – 2004 Lead Agency: USDA Forest Service, Pacific Southwest Region Authors: Jay D. Miller Remote Sensing Specialist Fire, Fuels and Aviation Management Pacific Southwest Region Hugh D. Safford Regional Ecologist Pacific Southwest Region August 2008 This page has no content. Sierr a Nevada Fire Sever it y Monitoring 1984 – 2004 Table of Contents Executive Summary..............................................................................................................1 Background......................................................................................................................1 Objectives........................................................................................................................1 Approach.........................................................................................................................1 Findings...........................................................................................................................2 Discussion........................................................................................................................3 Applications.....................................................................................................................5 Introduction..........................................................................................................................6 Background......................................................................................................................6 Objectives........................................................................................................................8 Approach.........................................................................................................................8 Spatial Extent and Time Period Covered......................................................................9 Wildland Fire Use fires.............................................................................................10 Ecological Stratification for Reporting.......................................................................11 Remot e Sensing and Field Calibrat ion Dat a................................................................12 Fire Severity Ratings Based on the Composite Burn Index..........................................13 Fire Severity Ratings Based on Tree Mortality............................................................15 Stratification by Vegetation Type..............................................................................16 Fire Regime Concept ................................................................................................18 Results ................................................................................................................................21 Summary of Fires Mapped..............................................................................................21 Fires from 2000 through 2004.........................................................................................21 Severity by Vegetation Type...........................................................................................22 Comparison of 1984-2004 fires with SNFPA FEIS analysis.........................................23 Current versus pre-settlement patterns in severity.......................................................25 Severity in Wildland Fire Use (WFU) vs. Wildfires (WF) .................................................26 Trend Analysis...............................................................................................................28 Trend in Severity by Vegetation Type 1984-2004.......................................................29 Trend in Fire Size and High Severity Patch Size 1984-2004........................................37 Trend in Fire Size and Burned Area 1908-2006..........................................................41 Fire Correlations with Climate...................................................................................44 Applications of Fire Severity Data ......................................................................................49 Appendix A: Methods.........................................................................................................51 Appendix B: Severity by Vegetation Type...........................................................................62 Appendix C: Individual Fire Results...................................................................................79 References...........................................................................................................................97 i Sierr a Nevada Fire Sever it y Monitoring 1984 – 2004 List of Tables Table 1. Number of acres by ownership in mapped fires................................................................................................................................10 Table 2. Number of fires within each latitudinal zone....................................................................................................................................12 Table 3. CBI based severity categories..............................................................................................................................................................14 Table 4. CALVEG dominance type groupings.................................................................................................................................................16 Table 5. Historic fire regime types for SNFPA vegetation types (adapted from Sugihara et. al. 2006)................................................20 Table 6. Number and percent acres burned 2000 through 2004 for conifer vegetation types by severity category............................22 Table 7. Number of acres from mapped 1984-2004 fires analyzed by regional vegetation type on U.S. Forest Service administered lands..........................................................................................................................................................................................23 Table 8. The average percent of acres burned by regional vegetation type, fires 1984-2004 vs. percentages used for the SNFPA FEIS..................................................................................................................................................................................................................25 Table 9. Fires used in WFU vs. WF comparison..............................................................................................................................................27 Table 10. Number and percent of acres burned for conifer vegetation types by severity category in WFU and WF fires on Forest Service administered land.............................................................................................................................................................................28 Table 11. Regression statistics for results of ARIMA time series modeling of trends in high severity fire and high severity patch size, 1984-2004...............................................................................................................................................................................................31 Table 12. Contiguous high severity conifer patches greater than 1000 ac. on U.S. Forest Service administered lands in 1984-2004 mapped fires....................................................................................................................................................................................................41 Table 13. Fire-climate regression results...........................................................................................................................................................47 ii Sierr a Nevada Fire Sever it y Monitoring 1984 – 2004 List of Figures Figure 1. Comparison of BAER soil burn severity map to vegetation based severity map.......................................................................7 Figure 2. Location and time period of fires with respect to Landsat path/row location.............................................................................9 Figure 3. Stratification of fires corresponding to latitudinal ecological zones...........................................................................................12 Figure 4. Example field plot photos of CBI based severity