Don Falk, University of Arizona. Restoration and Ecological Resilience in a Changing World

Transcription

1 Don Falk, University of Arizona Restoration and Ecological Resilience in a Changing World Healthy Headwaters, Phoenix, AZ April 2012

2 The iconic images of our time are expressions of rapid, global change in the Earth system NASA-Goddard GFDL Model; IPCC 2007

3 Arguably the central scientific and management question of our time: How will ecosystems and organisms adapt to rapid reorganization of the Earth system?

4 Central questions: 1. What are the trajectories of ecosystems under current and emerging climate conditions? 2. What are our adaptive responses for current and future ecosystem management?

5 Fires are naturally very frequent in many SW ecosystems Fires at > 25% of recording sites, Valles Caldera National Preserve, NM (Dewar 2011)

6 Widespread fire years V. SAN ANTONIO V. SAN ANTONIO V. TOLEDO V. TOLEDO V. SECO V. SECO ALAMO BOG V. JARAMILLO ALAMO BOG V. JARAMILLO V. GRANDE V. GRANDE EL CAJETE EL CAJETE

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9 The ongoing focus on suppression is an expensive pathway Adapted from Holmes et al

10 Trend in annual area burned Significance of trend, Mann-Kendall Test

11 Projected change in climate ( vs ), A1B Projected percent change in annual area burned ( vs ) A1B JFM temperature AMJ temperature JAS temperature R 2, models P<0.05 Last day of permanent snow

12 Are we keeping up with the challenges of fuels and climate? Conver et al., in prep.

13 Interactions between climate change, disturbance, and other stressors may be leading ecosystems in new trajectories Cochiti Canyon, Jemez Mountains, NM, following the 2011 Las Conchas Fire

14 Large contiguous highseverity patches (10 4 ha) Interactions with previous events (e.g ) fires Tipping-point system behavior into new ecosystems Figure: A. Thode, NAU

15 Is there a better alternative? Fire suppression costs alone $500-1,000/ac, not including burned area rehabilitation, insurance and property losses Investing just 10% of the $1.2 billion suppression budget in restoration would treat more than a million acres per year and employ thousands of people Restoration must be redefined as an investment, not a cost to be avoided

16 Miller Fire: An important reference fire that demonstrates what happens when fire is allowed to stay in the system Preliminary burn severity in the Miller Fire, Gila Wilderness

17 Corta Alloza, Spain Pune, India Costa Rica Port Elizabeth, South Africa

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19 Classic restoration paradigm Predictability Resilience ecology paradigm Stochasticity Target species Equilibrium Persistence Stasis Hot spots Sites Mean Composition Past-present reference Populations, communities Complexity Resilience Adaptability Dynamics Connectivity Landscapes Variance, higher moments Process, function Past-present-future continuity Ecosystems, fluxes

20 FireScape: Restoring fire and ecosystems at large scales in the Sky Islands bioregion?

21 Five principles for monitoring and restoring ecosystems in a changing world 1. Manage for resilience and adaptive capacity, not steady state 2. Allow for the natural range of variability, understand history 3. Emphasize restoration of ecosystem processes 4. Focus on the landscape and regional scales 5. Monitor change across scales of space and time

22 Thanks: Craig Allen and Julio Betancourt, US Geological Survey Erica Bigio, Josh Conver, Jacquie Dewar, Matt Hall, Tom Swetnam, University of Arizona Peter Brown, Rocky Mountain Tree-Ring Research Cal Farris, National Park Service Thomas Kitzberger, Universidad Nacional del Comahue, Argentina Bob Parmenter, VCNP Elaine Sutherland, US Forest Service Tony Westerling, University of California Merced FACS contributors

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25 Are species range shifts an example of adaptation, or a problem to be addressed? Now Overall prediction: PIPO abundance declines 13% by % of 2090 distribution is in new areas not currently occupied 27 36% of current stands remain in situ Most lost area is in southern limit of range Rehfeldt et al. Int. J. Plant Sci., 2006

26 Fire and Climate Synthesis (FACS): A major new network for continental paleoecology 1,248 sites 64 contributors 3,248 years (1248 CE 2011 CE) Fire-scar based, focused on frequent-fire systems 7 primary forest types > 15,000 fire site-years Falk et al. 2010, 2011, in prep.