Climate Change, Forests, Fire, Water, and Fish: Building Resilient Landscapes, Streams, and Managers
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Climate Change, Forests, United States Department Fire, Water, and Fish: of Agriculture Forest Service Rocky Mountain Building resilient landscapes, streams, Research Station and managers General Technical Report RMRS-GTR-290 September 2012 Charles Luce, Penny Morgan, Kathleen Dwire, Daniel Isaak, Zachary Holden, and Bruce Rieman Luce, Charles; Morgan, Penny; Dwire, Kathleen; Isaak, Daniel; Holden, Zachary; Rieman, Bruce. 2012. Climate change, forests, fire, water, and fish: Building resilient landscapes, streams, and managers. Gen. Tech. Rep. RMRS-GTR-290. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 207 p. ABSTRACT Fire will play an important role in shaping forest and stream ecosystems as the climate changes. Historic observations show increased dryness accompanying more widespread fire and forest die-off. These events punctuate gradual changes to ecosystems and sometimes generate stepwise changes in ecosystems. Climate vulnerability assessments need to account for fire in their calculus. The biophysical template of forest and stream ecosystems determines much of their response to fire. This report describes the framework of how fire and climate change work together to affect forest and fish communities. Learning how to adapt will come from testing, probing, and pushing that framework and then proposing new ideas. The western U.S. defies generalizations, and much learning must necessarily be local in implication. This report serves as a scaffold for that learning. It comprises three primary chapters on physical processes, biological interactions, and management decisions, accompanied by a special section with separately authored papers addressing interactions of fish populations with wildfire. Any one of these documents could stand on its own. Taken together, they serve as a useful reference with varying levels of detail for land managers and resource specialists. Readers looking for an executive summary are directed to the sections titled “Introduction” and “Next Steps.” ACKNOWLEDGMENTS This synthesis was funded by the Joint Fire Sciences Program. The authors wish to thank a large number of people who have participated in discussions on synthesizing these ideas. We would particularly like to thank three colleagues who joined us in a workshop in February 2009 but did not have the time to join in the preparation of this GTR: Matt Dare, Claire McGrath, and John Buffington. We would also like to thank the authors of the Advanced Topics papers: Robert Gresswell, Jason Dunham, Helen Neville, Amanda Rosenberger, Mike Young, and John Rinne. You may order additional copies of this publication by sending your mailing information in label form through one of the following media. Please specify the publication title and series number. Publishing Services Telephone (970) 498-1392 FAX (970) 498-1122 E-mail [email protected] Website http://www.fs.fed.us/rm/publications Mailing address Publications Distribution Rocky Mountain Research Station 240 West Prospect Road Fort Collins, CO 80526 Climate Change, Forests, Fire, Water, and Fish: Building resilient landscapes, streams, and managers Charles Luce, Penny Morgan, Kathleen Dwire, Daniel Isaak, Zachary Holden, and Bruce Rieman with Advanced Topics on Fish Populations and Fire by various authors United States Department of Agriculture Forest Service Rocky Mountain Research Station General Technical Report RMRS-GTR-290 September 2012 CONTENTS Introduction .............................................................................................................1 Key Debates ....................................................................................................................... 3 Framing Solutions ............................................................................................................... 4 Part I: The Physical System .......................................................................................8 A. Climate ................................................................................................................................... 8 Climate Change .................................................................................................................. 8 Fire ................................................................................................................................... 14 B. Hydrology ............................................................................................................................. 15 Climate Change ................................................................................................................ 15 Fire ................................................................................................................................... 21 Fire and Climate Change: Feedback and Cumulative Effects ............................................. 26 Implications for Aquatic Biota .......................................................................................... 27 C. Stream Temperature .............................................................................................................. 28 Climate Change ................................................................................................................ 28 Fire ................................................................................................................................... 30 Implications for Aquatic Biota .......................................................................................... 31 D. Geomorphology .................................................................................................................... 32 Climate Change ................................................................................................................ 32 Fire ................................................................................................................................... 33 Part II: Biological Systems ......................................................................................39 A. Forests, Climate Change, and Fire ......................................................................................... 39 We Live in a Fire Environment .......................................................................................... 39 Changing Fire Regimes ..................................................................................................... 40 Burn Severity .................................................................................................................... 42 Burn Severity Indicators Inferred From Satellite and Field Data ......................................... 45 Will Future Fires be Larger and More Severe, and If So, So What? .................................... 47 Fuel Treatment Effectiveness ............................................................................................. 47 Bark Beetles and Burn Severity ......................................................................................... 48 Key Uncertainties ............................................................................................................. 49 Fire Management Strategies .............................................................................................. 50 Summary .......................................................................................................................... 51 B. Riparian Forests, Climate Change, Fire .................................................................................. 51 Riparian Vegetation, Values, and Connection to Streams ................................................... 51 Disturbances in Riparian Areas ......................................................................................... 59 Flooding ........................................................................................................................... 60 Fire ................................................................................................................................... 61 Climate Change, Fire, and Riparian Values and Functions ................................................ 72 C. Fish, Fire, Forest Management, and Climate Change ............................................................. 74 The Responseo of Fish Populations to Fire ........................................................................ 76 Interaction With Land Management .................................................................................. 79 Interactions With a Changing Climate .............................................................................. 81 Connections to Conservation ............................................................................................ 85 Part III: Management Actions and Decisions ..........................................................87 A. Actions .................................................................................................................................. 87 Action Choices ................................................................................................................. 87 Effectiveness of Actions .................................................................................................... 88 B. Framing Issues and Decisions ................................................................................................ 90 The Broad Scope of Debate .............................................................................................. 90