Treesearch

Most prescribed fire plans focus on reducing wildfire hazards with little consideration given to effects on wildlife populations and their habitats. To evaluate effectiveness of prescribed burning in reducing fuels and to assess effects of fuels reduction on wildlife, we began a large-scale study known as the Birds and Burns Network in 2002. In this paper we analyze changes in downed wood and forest structure (trees and snags) measured within one year after prescribed fire treatments that were completed in ponderosa pine (Pinus ponderosa) forests in Arizona and New Mexico (Southwest...

Surface and crown fuels were measured in 186 stands ranging in age from 0 years after clearcutting to old-growth forests > 300 years old in Douglas-fir (Pseudotsuga menziesii) – western hemlock (Tsuga heterophylla) – western redcedar (Thuja plicata) – dominated forests in southwestern British Columbia. Indexes of surface fire hazard based on woody debris loads, and of crown fire hazard based on 5 factors (canopy foliar bulk density, height to live crown, woody debris loads, ladder fuels, and snag quantities), were developed. Using the indexes developed, surface fire hazard followed a...

Understanding and calculating fire behaviour in various fuel types is essential for effective fire management, including wildfire suppression and fuels management. Fire spread in grassland fuel is affected by the curing level, the amount of dead fuel expressed as a percentage of the total (live and dead fuel combined). The influence of live fuel is included in various fire models in different ways. U.S. fire behavior prediction systems are based on Rothermel’s fire spread model, which uses the load of live and dead fuel and the moisture content of each. Dynamic fuel models include a...

Foliar moisture content (FMC) is a primary factor in the canopy ignition process as surface fire transitions to crown fire. In combination with measured stand data and assumed environmental conditions, reasonable estimates of foliar moisture content are necessary to determine and justify silvicultural targets for canopy fuels management strategies. FMC values reported in research publications are best used for this purpose. This paper summarizes the results of 11 studies on the FMC values and trends for 16 North American conifers. FMC values ranged from 73 to 480 percent but varied by...

Fire risk is an ever present management concern in many urban interface regions. To mitigate this risk, land management agencies have expanded their options beyond prescribed fire to include vegetation mastication and other mechanical fuel treatments. This research project examined fire severity and intensity in masticated and unmanipulated units that were burned in spring in a Northern California mixed shrub woodland. Mastication treatments significantly altered the fuel profile, resulting in an approximate 200 percent average increase in woody fuel cover for 1-hr and 1000-hr TLFM size...

We compared the accuracy and precision of digital hemispherical photography and the LI-COR LAI-2000 plant canopy analyzer as predictors of canopy fuels. We collected data on 12 plots in western Montana under a variety of lighting and sky conditions, and used a variety of processing methods to compute estimates. Repeated measurements from each method displayed considerable variability, but hemispherical photography proved to be the more precise method. To evaluate the accuracy of the different methods, we correlated measurements with allometrically derived estimates of canopy bulk density...

Resource managers need spatially explicit fuels data to manage fire hazard and evaluate the ecological effects of wildland fires and fuel treatments. For this study, fuels were mapped on the Okanogan and Wenatchee National Forests (OWNF) using a rule-based method and the Fuels Characteristic Classification System (FCCS). The FCCS classifies fuels based on their combustion properties, producing unique “fuel beds,” each of which represents a distinct fire environment. Managers on the OWNF identified 187 fuel beds which were consolidated into 40 general fuel beds representing the major...

The objective of this study is classification of fuel type and calculation of fuel loading to assess forest fire hazard by fuel characteristics at Uiseong-gun, Gyeongbuk located in the central interior of Korea. A database was constructed of eight factors such as forest type and topography using ArcGIS 9.1 GIS programs. An on-site survey was conducted for investigating vegetation and fuel loading. Forest distribution of Uiseong-gun is composed of mixed forest, about 43.7%, of coniferous trees such as Pinus densiflora, approximately 43.5%, and of broad-leaved trees like Quercus variabilis,...

Measuring success of fuels management is improved by understanding rates of litter accumulation and decay in relation to disturbance events. Despite the broad ecological importance of litter, little is known about the parameters of accumulation and decay rates in Ozark forests. Previously published estimates were used to derive accumulation rates and combined litter measurements, model estimates, and fire scar history data were used to derive a decay constant (k = 0.38). We used accumulation equations to demonstrate temporal changes in litter loading. For example, after a fire event that...

Masticated fuel treatments that chop small trees, shrubs, and dead woody material into smaller pieces to reduce fuel bed depth are used increasingly as a mechanical means to treat fuels. Fuel loading information is important to monitor changes in fuels. The commonly used planar intercept method however, may not correctly estimate fuel loadings because masticated fuels violate the assumption that fuel particles are round. A sampling method was developed for estimating masticated fuel bed loadings using percent cover, average depth, and bulk density in three vegetation types: Jeffrey...