NCEAS Working Group Proposal – January 2008 PYROGEOGRAPHY - FIRE’S PLACE IN EARTH SYSTEM SCIENCE Short title: What is fire? PI contact information: David Bowman School of Plant Science The University of Tasmania Private Bag 55 Hobart TAS 7001 Australia Phone (Int): +61 3 6226 1943 Email: [email protected] Jennifer Balch Yale University School of Forestry and Environmental Studies 205 Prospect Street New Haven, CT 06511 USA Phone: 202-360-0923 Email: [email protected] Summary: It is time to rethink the place of fire on Earth. Megafires are currently overwhelming human control, despite huge budgets and mature fire-fighting technologies. There is mounting evidence that, beyond immediate destruction of life and property, landscape fires have long-term effects on global carbon stocks, biodiversity, climate, world economies, and human health. Despite fire’s pervasive influence in many disciplines, there is no uniting theory or paradigm concerning the role of biomass burning in Earth science. Moreover, fire has not been satisfactorily considered by global change policy and ecosystem management. We, therefore, propose a thought experiment addressing (i) whether fire would evolve where carbon-based life is present, (ii) how it would evolve, and (iii) how humans, their cultures, and fire may have coevolved. We will combine knowledge about biomass burning across fields to develop an integrative paradigm of ‘pyrogeography’ that addresses these fundamental questions. This synthetic exercise will inform and coordinate participant’s research to derive global products that highlight how and where shifting fire regimes will have consequences for human health, property, and ecosystem services—including global terrestrial carbon stocks. Our outputs will be a succinct review paper, an edited volume, and a concise book that collectively will: (i) provide a conceptual framework to account for the variation of fire types (intensity, frequency, and extent) in space, time, and amongst cultures, (ii) set out working hypotheses that will guide future work, and (iii) identify major omissions of fire's important role in Earth science and management. These outputs are a prerequisite for adaptation to the apparent recent intensification of fireclimate-vegetation feedbacks, which have been exacerbated by climate change, rapid land cover transformation, and exotic species introductions that challenge the evolutionary integrity of entire biomes. Proposed Start and End Dates: May 2008-June 2009; Deliverables expected to be complete by December 2009. Problem statement: Vegetation and fire are inextricably linked: plants create potential fuel from light, carbon, nutrients, and water, and fire consumes that fuel re-releasing those same elements. In geological time landscape fires occurred shortly after vegetation established (Scott 2000). A critical evolutionary event for our species was learning to use fire skillfully to achieve immediate utilitarian applications (Price 1995, Wrangham et al. 1999, Pyne 2001). More controversially, humans may have caused long-range environmental modification of landscapes, becoming ‘firekeystone species.’ Despite the intimate association of humans with fire, our understanding of the ecology of fire remains ambiguous and incomplete—advancing little beyond the ancient belief that fire is an elemental force along with air, water, and earth. The difficulty in answering ‘what is fire and why it is important?’ reveals fundamental and unaddressed gaps in knowledge. Framing these issues and operationalizing research questions lies at the heart of our proposal. Concern about global climate change and the recent spate of destructive fires on all vegetated continents has thrown a scientific spotlight on landscape fires. Recent ‘megafires’ in Southern California, Australia, Brazil, and other regions1, have placed fire management at the head of the political agenda and have stimulated scientists in disparate fields to recognize that landscape fire may be a considerably under-appreciated Earth system process. To bolster this claim we provide below a sketch of new perspectives that cut across disciplines from the humanities to hard sciences. First, fire has shaped the biosphere (Lenton 2001, Berner et al. 2003, Scott and Glasspool 2006). Geological evidence suggests that the advent of landscape fire was a direct consequence of the evolution of terrestrial vegetation (Scott 2000, In press). Fire has played a critical role in regulating Earth’s atmosphere via feedbacks with O2 and CO2, and the transfer of carbon into recalcitrant carbon pools (Kuhlbusch and Crutzen 1995). Falling CO2 levels and increased fire in the mid-Tertiary have been postulated as driving the evolution of the C4 photosynthetic pathway, thereby creating the novel, fire-adapted tropical savanna biome, which provided an evolutionary niche for large mammal grazers (Bond and Keeley 2005, Beerling and Osborne 2006). Moreover, Dynamic Global Vegetation Modeling (DGVM) has led to the radical hypothesis that fire is a primary determinant of Earth’s vegetation (Bond et al. 2005). Such fire-driven ecosystem dynamics could substantially alter terrestrial carbon stocks (Bird et al. 2000). Second, the ecological influence of prehistoric peoples’ landscape fire remains scientifically contentious, but has great relevance for fire management. Native American landscape burning is considered a negligible cause of past wildfires (Vale 2002), yet there are controversial claims that increased ignitions following human colonization in the late-Pleistocene caused the extinction of marsupial megafauna, triggered emergence of flammable Australian ecosystems, and changed climates (Johnson et al. 1999, Miller et al. 2005). This debate about prehistoric fire usage parallels concerns about the potential impact of current anthropogenic burning in humid tropical forests. Projected climate-driven replacement of part of tropical rainforests by savanna or grassland by the end of the 21st Century (Cox et al. 2004) could be exacerbated by wildfires of anthropogenic origin (Cochrane et al. 1999, Nepstad et al. 2001, Siegert et al. 2001). 1 Wood, D. B. 2007. California's age of megafires. Page 1 The Christian Science Monitor, USA.; Lean, G. 2007. More 'megafires' to come, say scientists. The Independent, London.; Ruffles, M. 2007. Megafires are the new reality of our summers. Page B05 The Canberra Times, Canberra. 2 Third, humans and fire may have coevolved. The controversial fireside hypothesis suggests that smoke pollution has influenced human evolution (Platek et al. 2002). Yet, there is far less doubt that air pollution generated from ‘megafires’ significantly affects human health (Sastry 2002, Mott et al. 2005, Sapkota et al. 2005, Chen et al. 2006, Jayachandran 2006, Moore et al. 2006). For example, the economic cost of haze from Southeast Asian fires in 1997-98 was between US$4.4-9.7 Billion, of which about US$1 Billion was attributable to short-term health costs (Lohman et al. 2007). In contrast to the above perspectives, the classic fire science and management paradigm has a far more narrow conception of fire. This paradigm treats landscape fire as: (i) a physical process that is amendable to predictive modeling (driven by the quest for ‘forecasting’), and (ii) an extrinsic ecological disturbance that demands human control. Inadequacies of the approach are apparent given the current failure to control fires—despite mature technologies and large operational budgets (Busenberg 2004). Clearly new ways of conceptualizing landscape fire are required (Pyne 2007), especially given the need to adapt to the increasingly frequent and intense fires that may be associated with climate change (Westerling et al. 2006). Proposed activities: While fire is increasingly recognized as integral to global ecology, it has not been effectively integrated into Earth systems science. Therefore we propose to undertake a thought experiment that addresses: Is fire a fundamental process on a planet with carbon-based life? And if so, what are the mechanisms by which fire develops and how would this influence evolution? Although thought experiments have rarely been used in ecology (Wilkinson 2006), their invented scenarios add to current knowledge by testing internal consistency of existing theory and by contextualizing across disjointed studies (Sorensen 1991). As such, thought experiments provide an ideal methodology for this working group (WG) to deconstruct and rebuild existing fire paradigms, evaluate current understanding of fire, and explore challenges to human adaptation to changing fire regimes. In order to engage the above questions we will conduct a broad synthesis that: (i) considers the co-evolution of life and fire and how fire structures biomes, (ii) gauges the evolutionary and ecological importance of prehistoric and contemporary human ignitions, and (iii) investigates human-fire thresholds, in terms of health and economic impacts, and greenhouse gas emissions. Specifically, we will: • Develop a framework (see Figure 1) for conceptualizing fire in Earth system science and outline a set of working hypotheses to direct future research and management. Participants have already been asked to outline key questions, readings, and gaps in understanding in their specific fields for a companion meeting sponsored by the Kavli Institute for Theoretical Physics (KITP). • Combine participant’s datasets and expert knowledge to: (i) develop a map of global fire hotspots—areas where shifting fire regimes are expected to have severe consequences for human health, property, and ecosystem services and (ii) determine the impact of fire on terrestrial carbon stocks and the balance between labile and recalcitrant carbon pools. • In conjunction with the working group, Balch (future NCEAS Postdoctoral Associate) will synthesize published data on fuel production, climate, and ignition sources with reconstructed fire histories in order to investigate the determinants of fire frequency across scales and ecosystems. Her results will provide mechanistic insights into historical fire patterns and bolster predictions of future fire regimes. 3 • Also, there is a unique opportunity to further expand on NCEAS capacity through collaboration with PI Moritz’s WG proposal, “The niche of fire and global pyrogeography.” The submission of two independent proposals is indicative of the surge in interest and pressing need to understand global fire. We see the two WG proposals as fundamentally different, but mutually beneficial. If both are funded, synergy would be created by having this WG provide framework and contextualized hypotheses, while Moritz’s WG would provide a statistical model of the conditions regulating global fire regimes. Balch would facilitate overall communication between groups as an NCEAS postdoc. Moreover, we would foster collaboration by: (i) conducting both WG meetings at the same time at NCEAS, and scheduling cross-over meetings on appropriate themes/tasks, and (ii) co-hosting a one-day symposium during the final WG meeting that would be open to the larger community. This ambitious program would not be possible without the unique opportunity afforded by NCEAS, which has earned a global reputation for fostering visionary reflection and synthesis in ecology. This proposal also offers a timely opportunity to take advantage of investments committed to Balch’s future work as an NCEAS Posdoctoral Associate, and to bring together our participants for the KITP Physics of Climate Change program. Timetable: The WG would meet three times, with six-month intervals between sessions. The first meeting, funded by KITP, is planned for May 26-June 8. We would hope to hold the second meeting in November 2008 and a third in June 2009, with product completion by December 2009. Moreover, to increase the impact of our outputs, we intend to time the release of some of our products with the United Nations climate change negotiations, which are expected to gain substantial momentum over the next two years. 4 Participants: All listed participants have confirmed their commitment to this WG. The group is composed of a diverse set of pure and applied researchers that includes women, international scientists and new and seasoned investigators with both theoretical and quantitative expertise in a broad set of fields (see Table 1). Table 1: Participant 1. David Bowman University of Tasmania, Australia 2. Jennifer Balch* Yale University, USA 3. Colin Prentice Bristol University, UK 4. Jean Carlson University of California-Santa Barbara, USA 5. Sandy Harrison Bristol University, UK 6. Michael Bird University of St. Andrews, UK 7. Jon Keeley USGS and UCLA, USA 8. Navjot Sodhi National University of Singapore, Singapore 9. Mark Cochrane South Dakota State University, USA 10. Ruth DeFries University of Maryland, USA 11. Paulo Artaxo Universidade de Sao Paulo, Brazil 12. Fay Johnston University of Tasmania, Australia 13. Stephen Pyne Arizona State University, USA 14. Thomas Swetnam University of Arizona, USA 15. William Bond University of Cape Town, South Africa 16. Guido Van Der Werf Vrije Universiteit, The Netherlands 17. Christian Kull Monash University, Australia 18. Andrew Scott University of London, UK 19. Reserved (Graduate Student) Expertise Pyrogeography of Australian forest ecosystems Tropical fire ecology Modeler of global carbon cycle Physics of fire behavior and emergent properties of complex systems Modeler of palaeo-Earth systems Palaeo-carbon processes using radio and stable isotopes Ecology of regeneration process and life-form spectra Tropical biodiversity and global environmental change Fire and tropical landscape change Global remote sensing and the interface with anthropogenic change Carbon, particulates, and climate Epidemiology and medicine of smoke particulates The cultural history of fire High resolution fire and climate records Ecology of the nexus of fire and herbivory Global biogeochemical cycles The politics of fire management Ancient fire records, fossil fuels, and new energy sources 20. Reserved (recommendations welcome) *Technical liaison responsible for NCEAS data policy 5 Anticipated results and benefits: Our WG will create a synthesis that establishes the place of fire in the evolution and functioning of the biosphere. To achieve this objective we intend to produce the following outputs from proposed activities: • • • Review/opinion piece of fire in Earth Systems science, suitable for a high-impact journal, An online special issue of Earth Interactions (editor already engaged and enthusiastic about publishing this collection) of collected papers from Balch and participant’s ongoing research that will provide up-to-date case studies and analyses that combined illustrate our proposed framework and hypotheses, and A brief review and synthesis appropriate for policymakers and the informed public that will be published in paperback and as an e-book (currently negotiating with WileyBlackwell). Overall, our work will provide new perspectives on landscape fire management in a changing world, clarify the importance of landscape fire in biological conservation and the global carbon cycle, and explore the nexus between landscape fire and human health and livelihoods. This working group will create an intellectual arena for consideration of fire in a global context (‘pyrogeography’), thus enabling currently fragmented scholars studying varied aspects of fire to value-add to each others’ work. Such a synergy of perspectives is crucial given the increasing evidence that the current fire management paradigm is unable to cope with the manifold challenges associated with (i) an expanding urban fringe into fire-prone wildland, (ii) increasingly severe fire weather associated with global climate change, (iii) more stringent air quality guidelines to regulate wildfire smoke, (iv) concern about the impact of fire on the global carbon balance, and (v) increasing disconnect between biodiversity conservation and fire management. How you heard about NCEAS: Balch, with momentum from recently awarded NCEAS postdoctoral fellowship, encouraged this submission to expand her future work at NCEAS. Initially, we heard about NCEAS from previous WG participants, Andy Dobson at Princeton University and Rob Whittaker at Oxford University, who highlighted the potential for a WG to create a synthesis of fire ecology. 6 Literature cited: Beerling, D. J., and C. P. Osborne. 2006. 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