USDA Forest Service
Global warming and climate change are poised to become defining environmental issues of the 21st century. Although future outcomes for this unprecedented change is uncertain, climate change in forested landscapes is expected to make itself felt directly upon species through changes in growth, reproduction and mortality; indirectly through changes in co-evolved relationships with insects and diseases, and through changes in disturbance regimes and invasive species. These changes could manifest themselves across spatial and temporal scales through changes to species extent, habitat fragmentation and reorganization of trophic relationships.
Climate FVS
The Forest Vegetation Simulator (FVS) is one of the key tools used by the US Forest Service to manage federal forest lands. For the past 35 years the model has been developed and expanded, so that it can now simulate forest growth across all of the United States. The model can also accommodate the impacts of a wide variety of insect, disease and fire effects at the stand and landscape. In its current formulation FVS is a set of theoretically constructed component submodels that are empirically calibrated to historical field data. Its growth and mortality predictions therefore assume that future conditions will be the same as those of the past. These assumptions are unrealistic in the face of changing climate, and ESSA has been assisting USFS scientists as they grapple with alternative approaches for transforming FVS into a climate sensitive model. Workshops have been held in 2007 and 2008 to consider the possible benefit of physiologically based growth and mortality models, changing species ranges and the inclusion of genetic variation (provenances) in the model. USFS scientists are continuing to explore and develop alternative approaches to including all these processes in FVS.
ESSA Technologies Ltd. 2007. Development of a climate-driven Forest Vegetation Simulator: the Priest River Experimental Forest workshop results. Prepared by ESSA Technologies Ltd., for Rocky Mountain Research Station, USDA Forest Service, Moscow, ID and the Forest Management Service Center, USDA Forest Service, Fort Collins, CO. 14 p.
ESSA Technologies Ltd. 2008. Development of a Climate-Driven Forest Vegetation Simulator: the Priest River Experimental Forest 2008 Workshop Results. Prepared by ESSA Technologies Ltd., for Rocky Mountain Research Station, USDA Forest Service, Moscow, Idaho and the Forest Management Service Center, USDA Forest Service, Fort Collins, CO. 26 p.
Preparing for Climate Change in US Forests
One of the great challenges of anticipating climate-driven changes is the absence of prior experience to guide expectations of the range of possible future outcomes. ESSA has provided help to USFS scientists from the Western Wildlands Environmental Threat Assessment Center (WWETAC) as they develop strategic and tactical programmes to support other Forest Service personnel. In an opening scientific workshop we examined the possible range of responses for four example ecosystems: pinyon-juniper, spruce-fir, ponderosa pine and northern boreal. The participants were led through a review of the existing threats of each ecosystem (e.g., epidemic insect outbreaks, drought stress). Current and future IPCC climate scenarios were also presented and domain experts (pathologists, silviculturists and entomologists) held brainstorming sessions to consider what surprises might face each system. The participants concluded that in the near future endemic pest outbreaks might resemble current epidemic outbreaks; species replacements are likely for ecosystems functioning at the “edge” of their physiological range; that cascades of interactions are to be expected; and that some areas of extreme risk may already be identified.
In a second workshop ESSA reviewed 5 classes of simulation tools that might be useful for National Forest managers as they prepare their forest plans: statistical species-distribution models, gap models, landscape simulation models, biogeochemical models and dynamic global vegetation models. In addition to a detailed review and summary process, the strengths and weaknesses of each model class were presented to the participants by an invited model proponent. The workshop concluded with recommendations for the development of practical training materials to assist managers in preparing climate-aware plans that emphasize a range of possible outcomes and appropriate responses to climate shifts.
Beukema, S.J., D.C.E. Robinson and L.A. Greig. 2007. Forests, insects & pathogens and climate change: workshop report. Prepared by ESSA Technologies Ltd., for Western Wildlands Threat Assessment Center, USDA Forest Service, Prineville, OR. 39 pp.
Robinson, D.C.E., S.J. Beukema and L.A. Greig. 2008. Vegetation models and climate change: workshop results. Prepared by ESSA Technologies Ltd., for Western Wildlands Threat Assessment Center, USDA Forest Service, Prineville, OR. 50 pp.
Halofsky, J. 2009. Understanding models of climate change impacts on vegetation and wildlife. Presentation to Olympic National Forest and Olympic National Park staff. 30 April 2009.