Treesearch

The forced flow driven flame spread behavior along an array of discrete wooden fuel elements was ex- perimentally investigated, which could be an important step to understanding the flow-flame interactions that govern fire spread. Fuel arrays with fiv e different spacings (0.75, 0.875. 1.00, 1.125, and 1.25 cm) were subject to flow speeds ranging from 2.2 to 4.3 m/s at approximately 0.2 m/s intervals. For spacing-flow speed conditions tested in the current study, the flame spread behavior was categorized into three different regimes, continuous, discrete, and quenching, and the regimes...

Pine barrens are open-canopy ecological communities once prevalent on sandy soils across the northern Great Lakes Region of the U.S. and Canada, though fire suppression and plantation forestry have now reduced them to a few isolated areas. Efforts to restore pine barrens are underway on some public lands, but lack of knowledge on the social and ecological issues and challenges that affect these projects impedes fuller progress. As a precursor to designing a public preference survey for pine barrens restoration, we sought input from those with expert knowledge about pine barrens. Using a...

Computational Fluid Dynamics (CFD) models are powerful research tools for studying fire dynamics. However, their application to wildland fire scenarios requires evaluation against relevant experimental data. To progress our current understanding of the fidelity of a CFD approach to simulating wildland fire dynamics, a dataset from an experimental fire was used as a test case. First, implications of the level of detail provided to the model, in the form of fuel structure and wind, are evaluated. Second, the predictions of both fire behavior (e.g. spread rate) and the driving combustion...

The effects of freestream flow on fire spread behaviors of a discrete wooden fuel array were studied. The spacing between fuel elements was varied, and the flame spread behavior under 1, 2, and 3 m/s forced flow velocities was investigated. The fastest spread rate was not observed for the smallest spacing. Furthermore, increasing spacing did not necessarily lead to a slower spread, as seen with the flame spread along the 0.75 cm spaced array which was as fast or faster than the 0.5 cm spacing condition. At a spacing of 1 cm, fragmented flames were observed at wind speeds of 3 m/s that...

Legacy effects from one disturbance may influence successional pathways by amplifying or buffering forest regeneration after the next disturbance. We assessed vegetation and tree regeneration in non-serotinous Sierra lodgepole pine (Pinus contortavar. murrayana) stands after a 1984 wildfire which burned with variable severity and again after a high-severity subsequent fire in 2012. The legacy effects of the 1984 fire were amplified; seedlings and saplings were abundant in areas initially burned at low severity (1267 stems ha−1) despite high reburn severity, but regeneration was low in...

Although the effects of shifting fire regimes on bird populations have been recognized as important to ecology and conservation, the consequences of fire for trophic interactions of avian species – and raptors in particular – remain relatively unknown. Here, we found that within national parks with long‐standing (40+ years) fire management programmes, California Spotted Owls Strix occidentalis occidentalisconsumed predominantly Woodrats Neotomaspp. and Pocket Gophers Thomomysspp.; however, in contrast to our predictions, when their territories experienced more extensive and frequent fire,...

In a quiescent atmosphere, the flame spread process in porous fuels is controlled to a large degree by the fuel bed structure, fuel loading and bulk density, and fuel moisture content. Previous studies have shown that increases in flame spread rate, fire intensity and burning rate are observed with independent increases in fuel loading or decreases in bulk density, however neither of these parameters adequately describe the physical processes that control flame spread. A series of laboratory-based, flame spread experiments involving fuel beds of differing fuel loading and structure were...

Energy is an integral part of society. The major US energy sources of fossil fuels (coal, oil, natural gas); biofuels (ethanol); and wind are concentrated in grassland ecosystems of the Great Plains. As energy demand continues to increase, mounting pressures will be placed on North American grassland systems. In this review, we present the ecological effects of energy development and production on grassland systems. We then identify opportunities to mitigate these effects during the planning, construction, and production phases by using informed methodology and improved technology. Primary...

Logging activities and its associated infrastructure are potential pathways for invasive forest plants, yet little is known about logger activities regarding invasive plants during logging operations. Logging business owners in Minnesota, USA were surveyed about invasive forest plants as a case study to learn about their awareness, interactions with landowners and land managers, actions to control the spread of invasives, perceived business impacts, and information needs. Fifty-one percent of respondents indicated they were either somewhat or very knowledgeable about invasive forest plants...

Many stressors plague bee populations including habitat fragmentation and degradation, as well as pathogens and pesticide exposure. With bee communities at risk, conservation efforts are imperative. Although recent research has examined bee communities across cities, few studies have analyzed variation in human attitudes toward and perceptions of bees, or how these perspectives might influence bee conservation. We therefore analyzed residents' attitudes toward and perceptions of bees, specifically in metropolitan Phoenix, Arizona. Primarily drawing upon 2017 survey data (n = 496, 39%...