School of Plant Science Yale University The University of Tasmania

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.
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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.
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•
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.
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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
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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.
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