Fire will be the proverbial eye-of-the-needle through which many western U.S. mountain, forest, and stream ecosystems will pass as the climate changes. Historic observations show increased dryness and temperatures accompanying more widespread fire and forest die-off. These events may punctuate gradual changes to ecosystems, or may be a mechanism driving stepwise changes in ecosystems. Most western ecosystems are strongly tied to cycles of fire and recovery, and the changing nature of fire will have profound consequences. There is no question that vulnerability assessments of western U.S. ecosystems need to account for fire in their calculus. The biophysical template of the forest, riparian, and stream ecosystems determines much of the response to fire. The degree of forest adaptation to fire, including fuel loading, fuel continuity, and species mixes are clear determinants of fire spread, fire severity, and the forest’s response. For aquatic systems the relative spatial scales of fire and connected fish habitats form another critical factor in longterm population persistence. Terrain, climate, and geology all exert controls on the hydrology of both forests and streams which sets much of the stage. Land and water management alter these contexts, sometimes dramatically, particularly those associated with scales of fuel continuity and aquatic fragmentation. Intertwined are the roles of invasive terrestrial and aquatic species and their roles in changing the scales of events and the connectivity and size of populations. Adaptation to climate change in the combined context of fire and climate change takes on greater dimensionality than management for either alone. Conceptually the detrimental contributions of prior human interventions provide substantial fodder for corrective action in anticipation of future severe events. However, an equally strong conceptual argument notes that restoration to historical conditions is itself an unstable solution at best. Despite clear knowledge that resistance, for example in the form of fire suppression, has built an unsustainable legacy of risk, resistive techniques will necessarily play future roles because the contexts are changing so fast. Sustainable approaches will rely on activities encouraging resilience in forests, riparian habitats, and streams alike, as opposed to those benefiting one ecosystem component at the expense of another. We also need to understand how human activities, even seemingly nurturing ones, can interfere with basic dynamic processes that form the foundation of resilience in fire adapted ecosystems. By understanding the processes reducing vulnerability to both severe disturbance and climate change, we can begin to envision many ways to facilitate more reliable positive outcomes for fire and related ecological dynamics. The future will likely require an increasing number of rapid decisions with a great deal of uncertainty about what will happen in the future, which would suggest that a present focus on reducing uncertainty about current resource conditions and limitations would be a wise investment. Adaptation taken in its most commonly used sense is about evolving, which is to say it is about learning; learning what works best. A principal goal of this GTR is to describe the framework of how we think that fire and climate change work together to affect fish communities. Learning will come from testing, probing, and pushing that framework to understand how it doesn’t work and then proposing new ideas. The western U.S. is a big place, with many diverse landscapes, defying generalizations and much learning must necessarily be local in implication. We present what we hope serves as a scaffold for that learning. This GTR comprises 2 parts: An overview document speaking to the breadth of processes interlinked by forests, fish, fire, and climate change, and a brief series of more specific and scholarly papers describing the biological interactions of fish, fire, and land management in more detail. 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. Background and Purpose Managing the balance between aquatic resources, wildfire, and fuel conditions has always been difficult, and is becoming further complicated by changes in climate that alter both aquatic ecosystems and wildfire characteristics. An important question is how we expect the changing nature of fire in the landscape and our shifting management responses to interact with the changing hydrologic and aquatic systems. Multiple federal agencies face this challenge and are looking for solutions. Several summaries of the effects of fire on aquatic ecosystems exist (Minshall et al., 1997, Gresswell, 1999, Rieman et al, 2003, Luce, 2005, Shakesby and Doerr, 2006). Since the last major summary, many results have come from National Fire Plan and Joint Fire Sciences Program funded studies. In addition a great deal has been recognized about the nature of climate change, how it affects fire, and how it directly affects aquatic systems. Finally, the fire management community has made dramatic changes in their approach to wildfire using Appropriate Management Response, giving fire a much larger role in landscape-scale vegetation management. Within hours of weather updates, decisions are now made that affect thousands to tens of thousands of acres. The stakes are higher and the decisions more complex. There is a need for an updated review and synthesis of how fire affects aquatic ecosystems, how it interacts with land, fuel, and fire management decisions, and how this all fits into the context of a changing climate. We prepared a synthesis and several focused papers highlighting recent research on fish and wildfire. We also conducted a workshop with line officers and specialists to to provide updated information and syntheses supporting management policies and decisions incorporating the best available science. Study description and location The project had two components: (1) a workshop with land and aquatic managers, (2) a synthesis of current research for managers. The purpose of the workshop was to gather insights about what was helpful from previous synthesis efforts, and what was needed from new synthetic work. Presentations from the workshop are included as deliverables. The written synthesis comprises four principle parts: (1) An overview and discussion of the different management concerns that come into play for managing for changing fire, (2) a multidisciplinary technical review of concepts and recent papers providing information about climate, fire, forests, riparian areas, hydrology, geomorphology, and fish, (3) several detailed papers on aspects of fish and fire interactions, and (4) management concepts including easily applied next steps. The more technical portions are intended to be relatively accessible outside of the disciplines and are meant to provide entry to the literature for specialists who may need more detailed information. The Endnote citation file is also included as a deliverable to assist in preparing NEPA specialist reports. Conceptual and technical figures will be made available separately to assist with public meetings. Key findings with one-two paragraph discussion of each From the workshop, it was clear that managers from all disciplines and line officers had a relatively clear understanding of the complexity of the issues facing them in managing for fish and fire in a changing climate. They had few questions about how to achieve results on the landscape, even where the fish, forests, and riparian areas were particularly sensitive. The managers were all familiar with the existing literature on fish and fire, and their purposes, goals, methods, and reasoning for their projects were largely in concordance with the recommendations from the synthesis team. They did express some concern and uncertainty about what changes in climate might mean for the success of the projects. The managers agreed that their primary problem was a lack of time and materials for explaining the complexity of the issues to the public (with varying levels of education) and being able to explain the technical reasons for the design choices made for projects. There was also interest in improving communications about technical issues across disciplines for similar reasons. They were interested in access to figures, references, and a brief summary of scientific results that could be brought to meetings or provided to the public to help explain why they were proposing the various projects. They were less interested in advice on how to proceed or design projects than in materials that would help them Generating the summary and synthesis of new research and further interaction with managers produced a few new ideas that were not covered at the workshop. Among these was the notion that many climate change projections have substantial uncertainty, and what that means for both forests and stream habitats is a great deal of uncertainty about how different threats may manifest. Another was that many managers were spending more of their time responding to fires, insect attacks, and other mortality events than actually planning and preparing. They noticed that the bottlenecks were preparing NEPA reports and reconciling emergency response actions with an outlook for the longerterm. The synthesis portion of the GTR addresses this apparent conflict and should help bolster and guide policy changes already occurring in the Forest Service, BLM, and Fish and Wildlife Service to provide decision support information for managers both responding to and planning for the consequences of climate change. Specifically, managers wanted faster access to information about conditions in their streams and forests and the known and projected vulnerabilities. They wanted to be able to summarize and display information about

Water plays a critical role in agriculture, energy, recreation, conservation, transportation, and indeed, life in the western United States. Water supply and variability in supply was paramount even before European settlers moved into the region. As demands on water have increased with time, all water related issues have also increased in importance to civilization. Water quantity issues drive western economics, politics, and demographics. Disturbance affects water quantity because precipitation and water use are controlled in part by land cover. The biogeochemical controls on water quality are closely tied to water quantity, but are also affected by landscape variability and both natural and anthropogenic disturbance. Slow recovery of forest vegetation may prolong the disturbance impacts on water quality in arid western basins compared to their relatively moist eastern counterparts. Sedimentation is a common cause of water quality impairment in actively managed landscapes. Riparian areas provide critical buffers to aquatic ecosystems from upland disturbances and may be integrators, magnifiers, or filters depending on the state of both the upland and riparian systems. Fisheries attract more attention than other aquatic resources and management of western water systems has had widespread impacts on fish habitat and populations. A general review of western issues with a Rocky Mountain and Fraser Experimental Forest focus is provided for water quantity, quality, fluvial, riparian and native fisheries issues. Headwaters of mid-latitude, western rivers systems are located in the Rocky Mountain cordillera, mountains of the basin and range region, Sierra Nevada, and coastal ranges. These physiographic features are particularly effective in producing the orographics that lead to higher precipitation rates than observed in nearby lowland regions. Northern hemisphere circulation produces moist westerly air mass flows from the Pacific that collide with these orographic barriers and the circulation is such that most of the precipitation comes as snowfall during the fall, winter and spring months. The end result is that the majority of annual precipitation for much of the region, as much as 75%, is stored in winter snowpacks in mountain regions. Potential evapotranspiration is also reduced at higher elevations due to cooler temperatures and limited growing seasons. These forested and alpine regions produce as much as 90% of the annual runoff as the snow melts in the spring and early summer. Because these source areas are largely federally managed, factors affecting the accumulation and subsequent ablation of the snowpack, as well as on-site consumptive use of water, place great pressure on agencies responsible for the source areas. As water resources become more limited due to increasing demand, the federal agencies managing the source areas are placed in a role of increasing conflict with multiple users with varied needs. Climate variability, recent prolonged droughts in particular, has accelerated both the demand and conflict in managing the resource. Management decisions must include consideration of downstream users' water rights, recreation, threatened and endangered species, in-stream flows, sedimentation, fire

Water plays a critical role in agriculture, energy, recreation, conservation, transportation, and indeed, life in the western United States. Water supply and variability in supply was paramount even before European settlers moved into the region. As demands on water have increased with time, all water related issues have also increased in importance to civilization. Water quantity issues drive western economics, politics, and demographics. Disturbance affects water quantity because precipitation and water use are controlled in part by land cover. The biogeochemical controls on water quality are closely tied to water quantity, but are also affected by landscape variability and both natural and anthropogenic disturbance. Slow recovery of forest vegetation may prolong the disturbance impacts on water quality in arid western basins compared to their relatively moist eastern counterparts. Sedimentation is a common cause of water quality impairment in actively managed landscapes. Riparian areas provide critical buffers to aquatic ecosystems from upland disturbances and may be integrators, magnifiers, or filters depending on the state of both the upland and riparian systems. Fisheries attract more attention than other aquatic resources and management of western water systems has had widespread impacts on fish habitat and populations. A general review of western issues with a Rocky Mountain and Fraser Experimental Forest focus is provided for water quantity, quality, fluvial, riparian and native fisheries issues. Headwaters of mid-latitude, western rivers systems are located in the Rocky Mountain cordillera, mountains of the basin and range region, Sierra Nevada, and coastal ranges. These physiographic features are particularly effective in producing the orographics that lead to higher precipitation rates than observed in nearby lowland regions. Northern hemisphere circulation produces moist westerly air mass flows from the Pacific that collide with these orographic barriers and the circulation is such that most of the precipitation comes as snowfall during the fall, winter and spring months. The end result is that the majority of annual precipitation for much of the region, as much as 75%, is stored in winter snowpacks in mountain regions. Potential evapotranspiration is also reduced at higher elevations due to cooler temperatures and limited growing seasons. These forested and alpine regions produce as much as 90% of the annual runoff as the snow melts in the spring and early summer. Because these source areas are largely federally managed, factors affecting the accumulation and subsequent ablation of the snowpack, as well as on-site consumptive use of water, place great pressure on agencies responsible for the source areas. As water resources become more limited due to increasing demand, the federal agencies managing the source areas are placed in a role of increasing conflict with multiple users with varied needs. Climate variability, recent prolonged droughts in particular, has accelerated both the demand and conflict in managing the resource. Management decisions must include consideration of downstream users' water rights, recreation, threatened and endangered species, in-stream flows, sedimentation, fire

The report comprises papers and abstracts from the Second Interagency Conference on Research in the Watersheds, May 16-18, Coweeta Hydrologic Laboratory, Otto NC. Authors from several agencies (e.g., USDA ARS, US-EPA, USFS) and the private sector contributed papers on topics ranging from new technology and analytical procedures, modeling, and hydrologic responses to disturbance. To ensure timely distribution, the report has been reproduced essentially as submitted by the authors. Papers received a minor amount of editing for consistency and formatting, but they have not been peer reviewed. The authors' views are their own and do not necessarily reflect those of the U.S. Department of Agriculture, the USDA Forest Service, the publisher, or the Coweeta Hydrologic Laboratory. Mention of trade names or commercial products in this report is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.