Document Type

Thesis - University Access Only

Award Date

2011

Degree Name

Doctor of Philosophy (PhD)

Department / School

Geospatial Science and Engineering

Abstract

Wildfire disturbance patterns and processes have been relatively well-studied in many geographic regions. Some of these studies demonstrate that forest roads and wildfires directly or indirectly influence the forest vegetation structure, composition and function. However, the influence of forest roads on fire regimes has received relatively little attention. Therefore, this dissertation focuses on a unique set of landscapes in the Okanogan - Wenatchee National Forests and their surrounding areas in the east Cascade Mountains, and more specifically addresses the degree to which the spatial patterns of wildfire ignitions, wildfire cessation, and bum severity patterns are influenced by forest roads and biophysical factors. I used geographical information systems and spatial analysis to explain the relative importance of forest road effects on the spatial patterns of human and lightning-caused ignitions, wildfire boundaries, and bum severity. I found that wildfire ignition was greater near gravel roads, wildfire boundaries occurred near roads, and bum severity was lower near roads for most of the fires. Three road effect mechanisms could explain these results: roads influence human access, roads act as a barrier, and roads create edge effects. This research suggests that recognizing road effects is important not only for wildfire management activities but also to emphasize the effects of fragmentation on road-interface fuel characteristics and conditions. I conclude that roads and their edge effect areas should be more widely acknowledged as a unique type of landscape effect because they influence fire regimes, and roads should be more rigorously studied and incorporated into wildland fire management and planning.

Library of Congress Subject Headings

Forests and forestry -- Fire management -- Cascade Range

Forests and forestry -- Fire management -- Washington (State)

Forest roads -- Environmental aspects -- Cascade Range

Forest roads -- Environmental aspects -- Washington (State)

Wildfires -- Prevention and control

Fire ecology

Format

application/pdf

Number of Pages

162

Publisher

South Dakota State University

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