Data for US wildfire activity analyses are typically acquired from archival summary reports of the federal or interagency fire organisations; incident-level wildfire reporting systems of the federal, state and local fire services; and, increasingly, remote-sensing programs. This paper provides an overview of these sources and highlights major reporting biases, inconsistencies and uncertainty within each.

Very large fires (VLFs) have important implications for ecosystems, air quality and fire suppression expenditures. Climate change projections suggest an increase in conditions conducive to VLF potential across most historically fire-prone regions of the US as well as changes in the seasonality of such conditions.

Associating daily National Fire Danger Rating System (NFDRS) indices with daily metrics of ongoing fire activity reveals that as fire danger increases there is a corresponding but seasonally dependent increase in both the average and variability in the daily number and daily growth of active incidents burning in the northern Rocky Mountains, USA.

Five severe wildfires between 2000 and 2008 provided a unique opportunity to study how burning influences plant communities across Appalachian landscapes. This study assessed how plant community structure, composition, cover, richness and diversity in unburned areas differed from areas burned once or twice.

We investigated the effects of fire on a climate-sensitive mammal, namely the American pika. Despite loss of canopy cover and understorey vegetation as a result of the fire, pikas were widely distributed and abundant after the fire. The fire did not alter microclimates relevant to pikas, highlighting the value of talus as a thermal refuge.

We explored post-wildfire nutrient ratios of soil and dominant plant species leaves and soil fungi : bacterial ratios in alpine meadows on the Qinghai-Tibet Plateau. The results indicated that wildfire reduces the supply capacity of nitrogen for plants relative to phosphorus and potassium in soils, and affects micro-organism composition by the change of multiple nutrient ratios.

This study uses spectral measurements to examine the reflectance characteristics associated with cellulose and lignin near 2100 nm and develops an index for dead grass fuel. We found that the regression functions based on the dead grass fuel index can be applied to estimate the amount of dead grass fuels.

Mechanical fuel treatments differ significantly between treatment types, yet all types alter fuel structure in shrub-dominated chaparral by transforming live-canopy fuels to a compacted layer of dead surface fuels. The effectiveness of these treatments, however, is short term due to the rapid regrowth of shrubs, and is compromised by the increase in herbaceous fuels.

Survival analysis methods are described and applied to demonstrate how to model the control time of wildland fires as functions of predictors. Historical forest fire data from Ontario, Canada are used for illustration, and models for lightning and people-caused fires are fit and compared.

We develop a method to value wildfire-potential information as a fire suppression decision-support tool. We demonstrate the method by calculating expected suppression expenditures for ‘with’ and ‘without’ information cases for a hypothetical management unit. The value of this information is defined as the difference in expected wildfire suppression expenditures.

Air transport sector and wildfires are considered relevant contributors to greenhouse gas emissions. We calculate the carbon footprint from a company owning 20 helitankers. We discuss the influence of the method, its implications and future actions for the reduction of greenhouse gas emissions. Our experience provides a useful pilot study.

We analysed the relationship between burned fraction and wind speed at the global scale. In contrast to findings of local-scale studies we found no increase in burned fraction with increasing wind speed. We conclude that fire spread equations based on local-scale observations need to be modified for use in global models.

F. Morandini and X. Silvani reported experimental heat fluxes and fire behaviour variables for five fires in Mediterranean shrub. They concluded that the calculated dimensionless variables for their two wind-driven fires did not satisfy previously reported criteria for identifying modes of heat transfer during fuel preheating. Re-analysis of the data has shown that the influence of slope on the fire behaviour was not accounted for and that the squared convective Froude number best describes mechanisms of heat transfer during the fires.

Fires propagating on a two-dimensional hill with wind perpendicular to the ridgeline can spread laterally owing to flow separation and develop a much wider fire front on the lee face of the hill. Experimental results at laboratory scale and field observations are reported to illustrate and model this phenomenon.

The Monitoring Trends in Burn Severity project produced a national atlas of burn severity for science and management applications in the US. However, the classified data product has considerable limitations that inhibit broader utility, which could be overcome through a national re-classification effort that ties the product to LANDFIRE.