GIS analyses of paleo-fire regimes in ponderosa pine (Pinus ponderosa) forests: Extending spatial approaches in ecological interpretation.
Date of Graduation
Fire is an inherently spatial process that is tightly coupled to spatial patterns in climate and topography. This is particularly true in the dry western United States, where confounded by the legacy of fire suppression and the trend in global warming, large high severity fires are increasingly frequent. Recent work has integrated space and time analyses of fire regimes through the application of geographic information science (GIS). GIS was developed for spatial studies, and it can be effective in multi-dimensional interpretations of fire ecology in many vegetated ecosystems. In order to examine the role of fire in dry ponderosa pine (Pinus ponderosa) forests of Eastern Washington State, I developed a novel approach for integrating spatial variability and traditional temporal measures of fire return interval, evaluated the role of regional drought on the spatial properties of fire and evaluated the effect of fuel age on spatiotemporal fire dynamics. Dendrochronological data collected by the United States Forest Service on several sites on the east slope of the Cascade Range were used in these analyses. I thoroughly edited and converted this secondary data to a format suitable for GIS applications. My work suggests that GIS can enrich and supplement traditional, statistical studies that emphasize temporal variability. Spatially explicit, visual representations of fire frequency can reveal relationships between fine-scale topographic features and fire. Spatial patterns of fire, particularly area burned and patchiness, appear to be directly related to annual drought. A spatially explicit, short-term relationship between fuel age and fire recurrence was also revealed. These results demonstrate that new insights can be gained through a spatiotemporal GIS-based analysis of fire variability, which through its visual nature is readily accessible to users with a wide range of expertise.
Kernan, James T., "GIS analyses of paleo-fire regimes in ponderosa pine (Pinus ponderosa) forests: Extending spatial approaches in ecological interpretation." (2009). Graduate Theses, Dissertations, and Problem Reports. 9168.