Treesearch

Forest thinning and prescribed fires are the main practices used by managers to address concerns over ecosystem degradation and severe wildland fire potential in dry forests of the Western United States. There is some debate, however, about treatment effectiveness in meeting management objectives as well as their ecological consequences. This study assesses the effectiveness of thinning and prescribed fire treatments, alone and combined, for modifying forest structure and potential fire behavior in the Eastern Cascade Mountains of Washington State. Treatments were applied to 12 management...

The objective of this paper is to present recommendations for fuels treatments in ponderosa pine forests in the Southwest, Colorado Front Range, and Black Hills of South Dakota. We have synthesized existing knowledge from the peer-reviewed literature and administrative studies and acquired local knowledge through a series of discussions with fuels treatment practitioners. We describe specific treatments, the circumstances under which they can be applied, and treatment effects. We provide recommendations related to where, how, and how often fuels treatments may be prescribed to achieve...

The conditions necessary for the combustion of canopy fuels are not well known but are assumed to be highly influenced by the volume through which the canopy fuels are dispersed, known as canopy bulk density (CBD). Propagating crown fire is defined as a continuous wall of flame from the bottom to the top of the canopy, implying crown fire propagation is actually independent of the vertical fuel distribution. We hypothesize that all foliar canopy fuel is available for the propagation of canopy fire. Therefore, we focus our effort on simplifying Van Wagner’s (1977) canopy fire propagation...

The FireLine Assessment MEthod (FLAME) provides a fireline-practical tool for predicting significant changes in fire rate-of-spread (ROS). FLAME addresses the dominant drivers of large, short-term change: effective windspeed, fuel type, and fine-fuel moisture. Primary output is the ROS-ratio, expressing the degree of change in ROS. The application process guides and instills a systematic methodology, utilizing a simple worksheet. The information developed provides a basis for safety judgments and for applying Lookouts, Communications, Escape routes, Safe zones (LCES). The ROS-ratio can be...

Data demonstrate the effect of slope on heading and backing fires burning through woody fuels. The data indicate that the upper limit of heading fire rate of spread is defined by the rate of spread up a vertical fuel array, and the lower limit is defined by the rate of spread of a backing fire burning downslope. The minimum spread rate is found to occur at nominally --16 degrees slope.

Canadian mixedwood forests have a high compositional and structural diversity. It includes both hardwood (aspen, balsam poplar, and white birch) and softwood (balsam fir, white spruce, black spruce, larch, and white cedar) species that can form pure stands or mixed stands. This heterogeneity results in a variety of vertical structural strata that can potentially interact with fire behaviour. Fourteen fire impact maps including information on preburn stand composition and structure were gathered in a Geographical Information System. The relative influence of prefire forest composition,...

This report highlights accomplishments achieved by USDA Forest Service National Fire Plan Research and Development projects from 2004 through 2005 in four key areas: firefighting, rehabilitation and restoration, hazardous fuels reduction, and community assistance. These highlights illustrate the broad range of knowledge and tools introduced and generated by the National Fire Plan Research and Development program.

We describe the efficacy of prescribed fires after two wildfires burned through and around these fires located in eastern Montana within the Missouri River Breaks. The objectives of the prescribed fires were to decrease tree density and favor increased herbaceous cover, thus decreasing the potential for crown fire. Our objective was to evaluate post-fire tree density, herbaceous cover, soil surface, and burn severity to determine if the prescribed fires fulfilled management objectives and if they affected post-wildfire outcomes. Because there is no information available on pre-fire...

Mastication has become a popular fuels treatment in the Western United States, but predicting subsequent fire behavior and effects has proven difficult. Fire behavior and effects in masticated fuelbeds have been more intense and erratic in comparison with model predictions. While various particle or fuelbed characteristics in these fuels may contribute to the inaccuracy of model predictions, an increase in particle surface area to volume ratio by the mastication process may affect moisture dynamics. The prediction of fuel moisture is critical to predicting fire behavior and effects in...

The 2nd Fire Behavior and Fuels Conference: Fire Environment -- Innovations, Management and Policy was held in Destin, FL, March 26-30, 2007. Following on the success of the 1st Fire Behavior and Fuels Conference, this conference was initiated in response to the needs of the National Wildfire Coordinating Group -- Fire Environment Working Team.