Climate change, disturbance regimes and forest resilience
Climate change, fire frequency, fire severity, forest resilience
Our early studies examining climate change focused on considering the potential consequences of climate change for forests or Greater Yellowstone (e.g., Graham et al. 1990, Romme and Turner 1991), and using simulation models to explore the landscape effects of altered fire regimes (e.g., Gardner et al. 1996, Schoennagel et al. 2006). Our ongoing studies consider how climate warming may affect fire regimes, forest structure and function, and carbon balance.
The frequency of large forest fires has increased in the western US since the mid 1980s in association with warmer temperatures and earlier spring snowmelt. Recent climate model projections suggest that, by the end of the 21st C, climate conditions like those of 1988 (the year of the large Yellowstone Fires) will represent close to the average year rather than an extreme year. The consequences of a climate shift of this magnitude for the fire regime, post-fire succession and carbon balance of western forest ecosystems are well beyond what scientists have explored to date. With recent funding from the JFSP New Initiatives program and in collaboration with Drs. Erica Smithwick (Penn State), Tony Westerling (UC-Merced), Mike Ryan (USFS) and Bill Romme (Colorado State), we extended our research to explore the implications of these current projections for fire in Greater Yellowstone. Key results of this work predict substantial increases in the frequency of large fires in Greater Yellowstone by the middle of the 21st Century (Westerling et al. 2012). We now strive to understand the ecological implications of such changes and how forested landscapes of the Rocky Mountains may change in coming decades.
With funding from an NSF Graduate Research Fellowship and an NSF Dissertation Improvement Grant, doctoral student Winslow Hansen is integrating field studies, experimentation, and process-based simulation modeling analysis to determine: (1) whether subalpine conifer forests of Yellowstone will remain resilient to projected changes in climate and fire and (2) the climatic and ecophysiological mechanisms that might underpin profound change in these forest ecosystems.
Gardner, R. H., W. W. Hargrove, M. G. Turner, and W. H. Romme. 1996. Climate change, disturbances and landscape dynamics. Pages 149-172 In: B. Walker and W. Steffen, editors. Global change and terrestrial ecosystems. Cambridge University Press, Cambridge, UK.
Graham, R. L., M. G. Turner, and V. H. Dale. 1990. How increasing atmospheric CO2 and climate change affect forests. BioScience 40:575-587.
Kashian, D. M., W. H. Romme, D. B. Tinker, M. G. Turner and M. G. Ryan. 2006. Carbon cycling and storage across coniferous landscapes: linking fire frequency, post-fire recovery, and ecosystem processes. BioScience 56:598-606.
Romme, W. H. and M. G. Turner. 1991. Implications of global climate change for biodiversity in the Greater Yellowstone Ecosystem. Conservation Biology 5:373-386.
Romme, W. H., M. S. Boyce, R. E. Gresswell, E. H. Merrill, G. W. Minshall, C. Whitlock and M. G. Turner. 2011. Twenty years after the 1988 Yellowstone fires: lessons about disturbance and ecosystems. Ecosystems 14:1196-1215.
Schoennagel, T., M.G. Turner, A. Fall and D. M. Kashian. 2006. Influence of fire regimes on lodgepole pine stand age and density across the Yellowstone National Park (USA) landscape. Landscape Ecology 21:1281-1296.
Smithwick, E. A. H., M. G. Ryan, D. M. Kashian, W. H. Romme, D. B. Tinker and M. G. Turner. 2009. Modeling the effects of fire and climate change on carbon and nitrogen storage in lodgepole pine (Pinus contorta) stands. Global Change Biology 15:535-548.
Turner, M. G. 2010. Disturbance and landscape dynamics in a changing world. Ecology 91:2833-2849.
Turner, M. G., D. C. Donato and W. H. Romme. 2012. Consequences of spatial heterogeneity for ecosystem services in changing forest landscapes: priorities for future research. Landscape Ecology (In press).
Westerling, A. L., M. G. Turner, E. A. H. Smithwick, W. H. Romme and M. G. Ryan. 2011. Continued warming could transform Greater Yellowstone fire regimes by mid-21st century. Proceedings of the National Academy of Sciences 108:13165-13170.