Document


Title

Ignition and burning characteristics of organic soils
Document Type: Conference Proceedings
Author(s): Roger D. Hungerford; William H. Frandsen; Kevin C. Ryan
Editor(s): Susan I. Cerulean; R. Todd Engstrom
Publication Year: 1995

Cataloging Information

Keyword(s):
  • black spruce
  • combustion
  • duff
  • duff moisture
  • fire
  • fuel moisture
  • heat transfer
  • ignition
  • moss
  • organic soils
  • peat
  • Picea mariana
  • soils
  • wetlands
Region(s):
Record Maintained By:
Record Last Modified: January 19, 2016
FRAMES Record Number: 2531

Description

Surface fires in wetland ecosystems frequently ignite smoldering ground fires. Ground fires often create and maintain open, shallow marshes that contribute to ecosystem diversity. Fire exclusion, drainage, deforestation, and other human activities have altered the landscape patterns and ecosystem processes in wetlands. Land managers who recognize the ecological role of fire want to use it as a management tool in wetlands. Conflicts between concerns such as air quality and ecosystem management objectives limit the range of acceptable fire prescriptions. Land managers need information on ignition and burnout of organic soils to successfully use fire in wetlands and to make decisions about allocating resources for wildfires. In this paper we review the current state of knowledge on the ignition and burnout of organic soils and present initial results of laboratory ignition and smoldering experiments with soils samples collected from North Carolina pocosins and Alaska black spruce boreal forests. Initial results from a prescribed burn in Alaska area also presented and contrasted with duff from the Northern Rocky Mountains. Ignitions tests were applied to black spruce and pocosin soil samples to determine the effect of soil moisture and mineral content on limits to ignition. Initial results for a range of inorganic contents indicate that pocosin soils will ignite at moisture contents from 25% to 100% higher than for peat moss and for feather moss from Alaska. The data suggest that bulk density and moisture content of organic materials may influence ignition and temperatures more than does soil origin. Temperatures observed in the combustion zone of prescribed fires and in laboratory burns of undisturbed soil cores are quite similar even for different organic materials. Soil temperature profiles (depth and magnitude of heating) are related to the duration of heating and the amount of organic material consumed. Lab and field data presented here are being used to validate and modify existing physical models that predict consumptions of organic material and heat transfer into the soil.

Citation:
Hungerford, Roger D.; Frandsen, William H.; Ryan, Kevin C. 1995. Ignition and burning characteristics of organic soils. Proceedings of the Annual Tall Timbers Fire Ecology Conference. Fire in wetlands: a management perspective. No. 19. Tallahassee, FL: Tall Timbers Research Station. pp. 78-91.