Treesearch

The International Association for Fire Safety Science (IAFSS) established the permanent working group known as LOF&BE (Large Outdoor Fires and the Built Environment), as an outgrowth of the 2017 Lund Workshops held in conjunction with the 12th IAFSS Symposium [1-3]. Subsequent workshops were held at the 11th Asia-Oceania Symposium on Fire Science and Technology (AOSFST) [4], Interflam 2019 [5], Virtual Workshops in 2020 [6], and 13th IAFSS Symposium (virtual) in 2021. LOF&BE aims to bring the community together to tackle large outdoor fire problems such as wildland fires, wildland-urban...

Background: Forest structural characteristics, the burning environment, and the choice of ignition pattern each influence prescribed fire behaviors and resulting fire effects; however, few studies examine the influences and interactions of these factors. Understanding how interactions among these drivers can influence prescribed fire behavior and effects is crucial for executing prescribed fires that can safely and effectively meet management objectives. To analyze the interactions between the fuels complex and ignition patterns, we used FIRETEC, a three-dimensional computational fluid...

Research on new conservation treatments for historical wood requires considerable amounts of appropriate wood material, which is hard to acquire. Thus, we produced biologically and chemically degraded model wood that could be used as a representative material in future research on consolidating agents. Using chemical composition determinations, we found that fungal decay targeted mainly polysaccharides, while alkaline treatment mostly reduced hemicelluloses and lignin content. X-ray and neutron scattering showed that all decayed samples had increased disorder in microfibril alignment and...

Invasive herbivores that kill foundation tree species pose a major threat to forest ecosystem sustainability. One important foundation tree species in the interior western United States is quaking aspen (Populus tremuloides Michx.), which is threatened by recent outbreaks of an invasive insect, oystershell scale (Lepidosaphes ulmi Linn.; OSS). OSS outbreaks were first reported in 2016, when OSS began causing dieback and mortality of aspen in wildland forest settings in northern Arizona. Since then, OSS has been observed in other locations across Arizona and in other western states, and...

Quaking aspen (Populus tremuloides Michx.) ecosystems are highly valued in the southwestern United States because of the ecological, economic, and aesthetic benefits they provide. Aspen has experienced extensive mortality in recent decades, and there is evidence that many areas in Arizona, United States lack adequate recruitment to replace dying overstory trees. Maintaining sustainable levels of regeneration and recruitment (i.e. juveniles) is critical for promoting aspen ecosystem resilience and adaptive capacity, but questions remain about which factors currently limit juvenile aspen and...

Emerald ash borer (EAB), a beetle from Asia that feeds on ash trees, was discovered as the cause of extensive ash mortality in southeast Michigan and adjacent areas of Canada in 2002. It is thought that this destructive pest was introduced in the early 1990’s in infested solid wood packaging material originating in Asia. EAB feeds on ash species in the genus Fraxinus causing widespread ash mortality and significant economic, environmental, and social impacts. As of March 2024, EAB infestations in the U.S. were known in Alabama, Arkansas, Colorado, Connecticut, Delaware, District of...

Changing climatic conditions are increasing overstory tree mortality in forests globally. This restructuring of the distribution of biomass is making already flammable forests more combustible, posing a major challenge for managing the transition to a lower biomass state. In western US dry conifer forests, tree density resulting from over a century of fire-exclusion practices has increased the risk of high-severity wildfire and susceptibility to climate-driven mortality. Reducing dead fuel loads will require new approaches to mitigate risk to the remaining live trees by preparing forests...

Economic feasibility of wood-based biorefinery depends on the development of efficient, environmentally acceptable, robust, and low-cost pretreatment technologies for the production of high-value products. Hydrothermal pretreatment successfully meets these needs because it is environmentally friendly and cost-efficient. Not only does this pretreatment effectively reduce the recalcitrance of wood to further conversion, it also provides suitable byproduct streams for the production of a broad palette of value-added products. High-value coproducts have been recognized as essential to the...

To understand the impacts of changing climate and wildfire activity on conifer forests, we studied how wildfire and post-fire seasonal climate conditions influence western larch (Larix occidentalis) regeneration across its range in the northwestern US. We destructively sampled 1651 seedlings from 57 sites across 32 fires that burned at moderate or high severity between 2000 and 2015; sites were within 100 m of reproductively mature western larch. Using dendrochronological methods, we estimated germination years of seedlings to calculate annual recruitment rates. We used boosted regression...

Understanding the factors influencing species range limits is increasingly crucial in anticipating migrations due to human-caused climate change. In the boreal biome, ongoing climate change and the associated increases in the rate, size, and severity of disturbances may alter the distributions of boreal tree species. Notably, Interior Alaska lacks native pine, a biogeographical anomaly that carries implications for ecosystem structure and function. The current range of lodgepole pine (Pinus contorta var. latifolia) in the adjacent Yukon Territory may expand into Interior Alaska, particularl...