Forest Ecosystems: Current Research

Regional Fire/Climate Relationships in the Pacific Northwest and Beyond



Fire exerts a strong influence on the structure and function of many terrestrial ecosystems. In forested ecosystems, the factors controlling the frequency, intensity, and size of fires are complex and operate at different spatial and temporal scales. Since climate strongly influences most of these factors (such as vegetation structure and fuel moisture), understanding the past and present relationships between climate and fire is essential to developing strategies for managing fire-prone ecosystems in an era of rapid climate change. The influence of climate change and climate variability on fire regimes and large fire events in the Pacific Northwest (PNW) and beyond is the focus of this project.

There is mounting evidence that a detectable relationship exists between extreme fire years in the West and Pacific Ocean circulation anomalies. The El Niño/Southern Oscillation (ENSO) influences fire in the Southwest (SW) and the Pacific Decadal Oscillation (PDO) appears to be related to fire in the PNW and Northern Rockies (NR). However, there are reasons to expect that processes driving fire in PNW, SW, and NR are not constant in their relative influence on fire through time or across space and that their differentiation is not stationary through time or across space.

Research Questions

A simple model of climate–fire-vegetation linkages

Figure 1 A simple model of climate–fire-vegetation linkages. This project emphasizes the mechanisms and variability indicated by (1).

Selected References

For publications on climate impacts on PNW forest ecosystems, please see CIG Publications.

Gedalof, Z. 2002. Links between Pacific basin climatic variability and natural systems of the Pacific Northwest. PhD dissertation, School of Forestry, University of Washington, Seattle.

Littell, J.S. 2002. Determinants of fire regime variability in lower elevation forests of the northern greater Yellowstone ecosystem. M.S. Thesis, Big Sky Institute/Department of Land Resources and Environmental Sciences, Montana State University, Bozeman.

Mote, P.W., W.S. Keeton, and J.F. Franklin. 1999. Decadal variations in forest fire activity in the Pacific Northwest. In Proceedings of the 11th Conference on Applied Climatology, pp. 155-156, Boston, Massachusetts: American Meteorological Society.