Treesearch

Concerns about smoke from large high-intensity and managed low intensity fires have been increasing during the past decade. Because smoke from large high-intensity fires are known to contain and generate secondary fine particles (PM2.5) and ozone precursors, the effect of fires on air quality in the southern Sierra Nevada is a serious management issue. Various process-based models have been developed for forecasting PM and ozone levels in the presence and absence of fires. Although these models provide deterministic predictions, few of them give measures of uncertainties associated with...

Mixed-conifer forests of southern California are exposed to nitrogen (N) deposition levels that impair carbon (C) and N cycling, enhance forest flammability, increase the risk of fire occurrence and air pollution emissions in fire, and increase nitrate runoff and soil N emissions both pre- and postfire. N-deposition abatement policies and prescribed fire treatments have been proposed to mitigate the interactive effects of fire suppression, N deposition, and wildfire occurrence. To test the most effective management options for N-enriched forests, a simulation study was done using a...

The chapters in Section III of this book provide an overview of how components of climate change, including air pollution, are likely to interact with fire in modifying key ecosystem processes, whether those processes were demographic, successional, or elemental cycling. These chapters primarily discuss increased temperature, reduced available soil moisture, and pollutant deposition or exposure as the key climate change attributes. Most of the chapters suggest that changes in frequency and intensity of disturbance regimes, such as wildfire and insect infestation, will likely be the...

Wildland fire occurrence and behavior are complex phenomena involving essentially fuel (vegetation), topography, and weather. Fire managers around the world use a variety of systems to track and predict fire danger and fire behavior, at spatial scales that span from local to global extents, and temporal scales ranging from minutes to seasons. The fire management application determines the makeup of the planning tool, which usually incorporates one or more computer models. Advanced computing technology has spawned a new generation of fire planning tools to predict fire occurrence and fire...

The accident of the Chernobyl nuclear power plant (ChNPP) in 1986 was probably the worst environmental disaster in the past 30 years. The fallout and accumulation of radionuclides in the soil and vegetation could have long-term impacts on the environment. Radionuclides released during large, catastrophic vegetation fires could spread to continental Europe, Scandinavia, and Russia. The potential for large fires occurring in the Chernobyl Exclusion Zone (EZ) was assessed based on vegetation conditions. We reviewed the composition of radionuclides in the soil and vegetation and in the...

As one of the most populous and geographically largest countries, China faces many problems including industrial growth, economic sustainability, food security, climate change, and air pollution. Interwoven with these challenges, wildland fire is one of the natural hazards facing modern China, especially under a changing climate. From a national perspective, wildland fire information is a fundamental and yet challenging prerequisite for understanding forest ecology and hazards in China. In recent years, China has begun to use remote sensing (RS) as a tool for monitoring regional fire...

Much of Australia is seasonally hot and dry, and fuel beds can become very flammable. Biomass burning ranges from annual savanna fires in the north to sporadic but extensive forest fires in the south. In addition, prescribed burning (the controlled application of fire) is being used more frequently as a means of reducing fuel loads, for maintenance of plant and animal biodiversity and in forestry practices. Despite this and in comparison to the Northern Hemisphere, there are few Australian studies of the production or composition of smoke from biomass burning. There is also relatively...

A warmer climate in western North America will likely affect forests directly through soil moisture stress and indirectly through increased extent and severity of disturbances. We propose that stress complexes, combinations of biotic and abiotic stresses, compromise the vigor and ultimate sustainability of forest ecosystems. Across western North America, increased water deficit will accelerate the normal stress complex experienced in forests, which typically involves some combination of multi-year drought, insects, and fire. Four examples suggest how stress complexes are region-specific....

Every year tens of millions of hectares of forests, woodlands, and grasslands burn globally. Some are burned intentionally for land conversion, pasture renewal or hazard reduction, or wildlife habitat improvement, but most are burned by uncontrolled wildfire. Estimates of burned area available in the literature vary widely, but satellite-based remote sensing data are increasing the accuracy of monitoring active fire and estimating burned areas. Recent data suggest that global wildfire emissions vary substantially from year to year. Nonetheless, average annual carbon emissions from wildfire...

In wildland fire management, reliable fire intelligence is needed to direct suppression resources, maintain firefighter safety, predict fire behavior, mitigate fire effects in the environment, and justify and evaluate the effectiveness of fuel management. Fire intelligence needs to be synoptic, quantitative, consistent, and timely. Airborne remote sensing with specialized infrared radiometers is now providing an unprecedented level of information on fire behavior and effects. The temperature, radiant intensity, carbon and sensible heat fluxes, and fuel consumption associated with the...