Ecological Role of Fire in Forest Ecosystems 1. Reduces probability of catastrophic fire 2. Nutrient input into soils 3. Control of insect pests 4. Control of tree pathogens 5. Maintains species diversity This project supported in part by the National Science Foundation. Opinions expressed are those of the authors and not necessarily those of the Foundation.

Fire reduces the probability of catastrophic fire Historical fire regime Historical fire regime Altered with fire suppression Altered with fire suppression Increased tree density and ladder fuels Increased tree density and ladder fuels “Staircase effect” “Staircase effect” Crown fires Crown fires

US Forest Service

Nutrient input into soils after fire NCSR

Nutrient input into soils Soil nutrients are usually tied up in organic matter Soil nutrients are usually tied up in organic matter Released in a pulse after fire Released in a pulse after fire Increased availability to plants and soil microorganisms Increased availability to plants and soil microorganisms Blackened soil increases rates of absorption of solar energy Blackened soil increases rates of absorption of solar energy High fire temperatures can volatilize some nutrients (e.g., nitrogen at >200 °C) High fire temperatures can volatilize some nutrients (e.g., nitrogen at >200 °C)

Control of insect pests USDA Forest Service

Control of insect pests Some insect populations are apparently controlled by fire Some insect populations are apparently controlled by fire High temperatures and smoke directly kill adults, larvae and eggs High temperatures and smoke directly kill adults, larvae and eggs Reduced tree density decreases susceptibility to insect attack Reduced tree density decreases susceptibility to insect attack Insect pests can also influence fire regimes Insect pests can also influence fire regimes

USDA Forest Service, Joseph O’Brien, Bugwood.org

Control of tree pathogens Spore germination inhibited by smoke in some fungi (e.g., annosus root rot) Spore germination inhibited by smoke in some fungi (e.g., annosus root rot) Spread of Phellinus weirii (laminated root rot) inhibited by fire Spread of Phellinus weirii (laminated root rot) inhibited by fire Spores of Port Orford cedar root rot are killed by fire and fire spaces trees making transmission from one tree to another less likely Spores of Port Orford cedar root rot are killed by fire and fire spaces trees making transmission from one tree to another less likely Dwarf mistletoe infestations are reduced by fire Dwarf mistletoe infestations are reduced by fire Some pathogens are promoted by fire (e.g., Rhizina undulata) Some pathogens are promoted by fire (e.g., Rhizina undulata)

Maintain species diversity Some forest types are fire-adapted Some forest types are fire-adapted

The Nature Conservancy: Ronald L. Myers, PhD

Plant adaptations to fire Serotinous cones Resin production Thick bark Rapid growth from roots Rapid colonization Virginia Tech University: College of Natural Resources National Park Service

National Park Service: Jim Peaco

National Park Service; Bryan HarryInset: University of Wisconsin: Jean-Michel Ane, Ph.D.

Forestry Images: Dale Wade, Rx Fire Doctor, Bugwood.org

Maintain species diversity Some forest types are fire-adapted Some forest types are fire-adapted Impacts on wildlife Impacts on wildlife

National Park Service: Jim Peaco Impacts of Fire on Wildlife Yellowstone Fires of 30,000 elk (1%) 350 of 30,000 elk (1%) 9 of 2500 bison (0.4%) 9 of 2500 bison (0.4%) Impacts of Fire on Wildlife Yellowstone Fires of 30,000 elk (1%) 350 of 30,000 elk (1%) 9 of 2500 bison (0.4%) 9 of 2500 bison (0.4%)

NCSR Forestry Images: Terry L Spivey US Fish and Wildlife Washington Biodiversity project

NCSR

USDA Agricultural Research Service: Scott Bauer

Kirtland’s warbler, jack pine and fire Federally endangered species Federally endangered species Limited range in northern Limited range in northern Michigan in young jack pine Michigan in young jack pine forests forests Habitat maintained historically Habitat maintained historically by fire by fire Jack pine is fire-adapted Jack pine is fire-adapted Decreased habitat due to Decreased habitat due to fire suppression fire suppression

The White House US Geological Survey

Washington Department of Fish and Wildlife Washington Department of Fish and Wildlife Forestry Images: Michael Mengak Forestry Images: Michael Mengak USFWS: John and Karen Hollingsworth

Maintain species diversity Some forest types are fire-adapted Some forest types are fire-adapted Impacts on wildlife Impacts on wildlife Insect specialists Insect specialists

Insect specialists Melanophila beetle (flat-head borers) breed in fire-damaged pines breed in fire-damaged pines eggs deposited below bark eggs deposited below bark larvae feed on cambium of newly larvae feed on cambium of newly killed trees adults are attracted by adults are attracted by heat and smoke heat and smoke Flybrain online Forestry Images: Petr Kapitola, State Phytosanitary Administration, Bugwood.org

National Park Service

Maintain species diversity Some forest types are fire-adapted Some forest types are fire-adapted Impacts on wildlife Impacts on wildlife Insect specialists Insect specialists Habitat diversity Habitat diversity

The mosaic nature of wildfire creates habitat diversity Biscuit Fire Southwest Oregon and Northern California Did not burn – 19% Did not burn – 19% Low intensity – 41% Low intensity – 41% Moderately burned – 23% Moderately burned – 23% Severely burned – 16% Severely burned – 16%

Preliminary Burn Severity Assessment Biscuit Fire Summer 2002 US Forest Service

Mosaic nature of wildfire is determined by several factors Variations in moisture levels of soil and fuel Variations in moisture levels of soil and fuel Vagaries of wind and weather Vagaries of wind and weather Past land use history Past land use history Past fire history Past fire history

Maintain species diversity Some forest types are fire-adapted Some forest types are fire-adapted Impacts on wildlife Impacts on wildlife Insect specialists Insect specialists Habitat diversity Habitat diversity

Ecological Role of Fire in Forest Ecosystems 1. Reduces probability of catastrophic fire 2. Nutrient input into soils 3. Control of insect pests 4. Control of tree pathogens 5. Maintains species diversity

Flybrain Online Flybrain Online Forestry Images: Various Photographers Forestry Images: Various Photographers National Park Service: Various Photographers National Park Service: Various Photographers NCSR – Wynn W. Cudmore PhD NCSR – Wynn W. Cudmore PhD Ron Austing, U.S. Fish and Wildlife Service Ron Austing, U.S. Fish and Wildlife Service The Nature Conservancy: Ronald L. Myers, PhD The Nature Conservancy: Ronald L. Myers, PhD The White House The White House University of Wisconsin: Jean-Michel Ane, Ph.D. University of Wisconsin: Jean-Michel Ane, Ph.D. US Fish and Wildlife: Various Photographers US Fish and Wildlife: Various Photographers US Forest Service US Forest Service US Geological Survey US Geological Survey USDA Agricultural Research Service: Scott Bauer USDA Agricultural Research Service: Scott Bauer USDA Forest Service USDA Forest Service Virginia Tech University: College of Natural Resources Virginia Tech University: College of Natural Resources Washington Biodiversity Project Washington Biodiversity Project Photo Credits