Document Type

Thesis - University Access Only

Award Date

2011

Degree Name

Master of Science (MS)

Department / School

Biology and Microbiology

Abstract

Anthropogenic influences following European settlement have contributed to overgrowth of ponderosa pine (Pinus ponderosa) forests leading to increases in extreme wildfire behavior and mountain pine beetle (MPB; Dendroctonus ponderosae) epidemics. Forest managers at Custer State Park, SD are using solar treatments, cutting and chunking of beetle-killed trees, to mitigate the ongoing MPH-epidemic and to try to reduce the concomitant increase in wildfire risk. Significant increases in 1-, 10-, 100-, and 1000-h sound, timelag surface fuel loads, among others, remain 4-5 years post-treatment compared to untreated, Black Elk Wilderness tree mortality. Fire modeling using the FlamMap system predicts that these treatments prevent extremes in fire spread rates (>97 m/min and < 3 m/min) by changing the bimodal distribution to a more normal distribution, thereby increasing predictability at the cost of increasing crown fire frequency as much as 60%. After two years, differences in crown fire frequency between treated and untreated areas diminish by up to 40%. Four years post-mortality, crown fire frequency differences are less than 5%, and average spread rates are reduced up to 18% by solar treatment. The ecological impacts of fire burning in recently solar treated areas are likely larger than untreated mortality due to increased crown and ground fire frequency. Management must be aware of the tradeoffs involved when prescribing solar treatments to MPB-affected areas, but the decrease in MPB populations and subsequent tree mortality due to treatment may be worth the temporarily increased risk of greater fire severity.

Library of Congress Subject Headings

Ponderosa pine -- Diseases and pests -- Control -- Black Hills (S.D. and Wyo.)

Forests and forestry -- Fire management -- Black Hills (S.D. and Wyo.)

Mountain pine beetle -- Control -- Black Hills (S.D. and Wyo.)

Wildfires -- Black Hills (S.D. and Wyo.) -- Prevention and control

Format

application/pdf

Number of Pages

87

Publisher

South Dakota State University

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