Treesearch

Observed fire spread rates from 240 laboratory fires in horizontally-oriented single-species live fuel beds were compared to predictions from various implementations and modifications of the Rothermel rate of spread model and a physical fire spread model developed by Pagni and Koo. Packing ratio of the laboratory fuel beds was generally greater than that observed in natural stands of chaparral. Fuel bed moisture content was greater than that in Rothermel's or in Wilson's data. Correlation between observed and predicted spread rate was 0 for Rothermel's original model and ranged from 0.07...

We examine the Esperanza fire, a Santa Ana-driven wildland fire that occurred in complex terrain in spatially heterogeneous chaparral fuels, using airborne remote sensing imagery from the FireMapper thermal-imaging radiometer and a coupled weather-wildland fire model. The radiometer data maps fire intensity and is used to evaluate the error in the extent of the simulated fire perimeter and to reveal dynamically active regions of the fire fronts, their intensity, and their depth. The simulations use a numerical weather prediction model tied to a fire behavior model to simulate fire growth,...

Residents’ trust in the managing agency has been heralded as a necessary precursor to success in preventing wildland fire losses in the wildland–urban interface. Trust, however, is a complex concept. Homeowners’ specific fire wise actions may not be easily linked to general measures of trust. This article uses two distinct trust indices to predict residents’ intention to do fire wise actions to their house and adjacent site. Results of structural equation models using a survey of Colorado Front Range residents (n=456) revealed strong explanatory power: 85% (house behaviours) and 72% (site...

In the last decade, increases in fire activity and suppression expenditures have caused budgetary problems for federal land management agencies. Spatial forecasts of upcoming fire activity and costs have the potential to help reduce expenditures, and increase the efficiency of suppression efforts, by enabling them to focus resources where they have the greatest effect. In this paper, we present statistical models for estimating 1–6 months ahead spatially explicit forecasts of expected numbers, locations and costs of large fires on a 0.1258 grid with vegetation, topography and hydroclimate...

In November 2003, the National Marine Fisheries Service received a petition from Homer T. McCrary to redefine the southern extent of the Central California Coast Coho Salmon Evolutionarily Significant Unit (CCC Coho Salmon ESU) to exclude populations that spawn in coastal watersheds south of the entrance to San Francisco Bay (i.e., the Golden Gate). The petitioner’s primary premise is that the coho salmon populations inhabiting this region for the last century are the result of introductions of nonnative stocks from locations north of San Francisco. The petitioner presented four main lines...

Most forestry property in Andalusia is privately held. One of the most important possibilities for economic development of rural areas is the use of pasture lands (dehesa in Spanish). During the spring–summer season, swine grazing takes advantage of grasses between the trees, and during winter (harsher times), they use Quercus tree fruit. Swine production has a direct economic impact on the rural areas' activities. Wildfires are the most significant disturbance in the Mediterranean ecosystems therefore; it is important to study the potential negative impact of wildfires on the swine...

Molecular evaluations of successful invaders are common, however studies of introduced species that have had limited invasion success, or have died out completely, are rare. We studied an introduced population of speckled dace (Rhinichthys osculus) from northern California, USA that has rapidly increased in abundance but remained restricted to a 25-km stretch of river since its introduction in the mid-1980s. Field and laboratory analyses indicate that invasion success of speckled dace is constrained by the combined effects of multiple predators. The role of bottleneck effects associated...

Habitat fragmentation is widely assumed to have negative effects on populations and communities, but some effects of fragmentation are subtle, difficult to measure and not always negative. For stream fish, barriers to upstream passage, such as waterfalls or culverts with perched outlets, are a common cause of fragmentation. We explored the effects of barriers on a virtual stream trout population occupying a network of reaches in the inSTREAM individual-based trout population model. The model includes daily habitat selection by individual fish, with barriers represented by assuming trout...

Simulation experiments using the inSTREAM individual-based brown trout Salmo trutta population model explored the role of individual adaptive behaviour in food limitation, as an example of how behaviour can affect managers’ understanding of conservation problems. The model includes many natural complexities in habitat (spatial and temporal variation in characteristics such as depth and velocity, temperature, hiding and feeding cover, drift-food supply and predation risk), fish physiology (especially, how food intake and growth vary with hydrodynamics, cover, fish size and temperature) and...

Over the past four decades teh contingent valuation method (CVM) has become a technique frequently used by economists to estimate willingness-to-pay (WTP) for improvements in environmental quality and prot3tion of natural resources. The CVM was originall applied to estmate recreation use values (Davis, 1963; Hammack and Brown, 1974)and air quality (Brookshire et al. 1982; Randall et al. 1974). In the second decade the CVM was extended to valuing the general public's option and existence values of environmental improvements (Walsh et al, 1984). As part of this evolution. the overall design...