Litter and Duff Bulk Densities in the Southern United States
 Final
Report to the Joint Fire Science Program [.pdf]
The organic layer (litter and duff) in forest, shrub,
and grasslands can represent the bulk of the fuels consumed during wildland
fires in southern ecosystems; it is imperative that organic layer depth
measurements can be converted to mass as managers often measure the
depth of the litter and organic duff layers. In order to convert depth
measurements to mass, a bulk density is required for each layer. Also,
the DMM600 Duff Moisture Meter developed through collaboration between
Campbell Scientific, Inc. and the USDA, Forest Service, Rocky Mountain
Research Station and Missoula Technology and Development Center measures
volumetric moisture of forest floor materials. These volumetric moisture
contents can be converted to gravimetric moisture content if duff bulk
density values are known.
Organic layer mass and duff moisture are critical variables
when estimating fuel consumption and potential fire effects such as
tree and shrub mortality, and smoke production during wildland fire.
Some field research has been conducted to quantify organic layer bulk
densities in the southeastern part of the United States, although it
has generally been limited to less productive sand pine and sand hill
sites at Eglin Air Force Base. The objective of this research proposal
was to quantify bulk density for litter and duff layers in 6 forest,
shrub, and grassland fuelbed types. The data was compiled and analyzed
to provide bulk density values for use in specific vegetation types.
Related Publications
Ottmar, Roger D.; Vihnanek, Robert E..; Wright Clinton
S. 2003. Stereo photo series for quantifying natural fuels in
the Americas. Abstract. In: Kush, John S., comp. Longleaf pine:
A southern legacy rising from the ashes, proceedings of the Fourth Longleaf
Alliance Regional Conference. Longleaf Alliance Report No. 6.
Full text
[.pdf]
Team Lead: Roger
Ottmar
Collaborators: Tall Timbers Research
Station, National Park Service, U.S. Fish and Wildlife Service
We
acknowledge funding from the Joint
Fire Science Program under Project JFSP 04-2-1-49.
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