Treesearch

When the Black Fire ignited in southwestern New Mexico in 2022, it had all the ingredients for disaster: record-high winds, extremely low humidity, and over 131,000 hectares (323,708 acres) of forest fuels to feed on. But something unexpected happened. Instead of becoming another catastrophic megafire, it burned mostly at low to moderate severity. The secret? The landscape had already experienced dozens of previous fires, both planned and natural, that helped tame the beast.

It’s no secret that wildland fires kill trees, but are more trees killed by fire when they are already stressed from drought? New research from the U.S. Department of Agriculture, Forest Service indicates that prefire drought can increase tree mortality after fire, even with the same level of tree damage.

Land managers rely on best available information and relevant research for decision making, but matching the right information to the right questions can sometimes be challenging. To close this gap, when researchers and managers co-produce research from the beginning it is more likely research findings will have practical applications. Recently published work by USDA Forest Service researchers Chris Armatas, Teresa Hollingsworth, and colleagues working at the Aldo Leopold Wilderness Research Institute (ALWRI) in Missoula, Montana, reflects on both the benefits and tradeoffs of using a...

Positron annihilation lifetime spectroscopy (PALS) was employed to study the waterdependent free volume characteristics of wood cell walls in earlywood and latewood of loblolly pine (Pinus taeda). Measurements were conducted across relative humidity levels (1–80% RH) at room temperature, demonstrating good reproducibility and consistency with polymer science principles. The Tao-Eldrup model was applied to the measured ortho-positronium lifetimes to estimate the mean sizes of free volume elements in wood cell walls. At low relative humidity (below ~ 11%), water absorption resulted in...

To demonstrate the effective use of a heterogeneous catalyst for the treatment of wastewater in a flowing state, we synthesized a metal–organic framework, MIL-88A, in situ on a filter paper. A cobalt doping modification yielded a composite catalyst, Co-doped MIL-88A, on a filter paper (Co-M88A-FP), which was then used to activate peroxymonosulfate (PMS). Characterizations of Co-M88A-FP catalyst revealed that the morphology and structure of MIL-88A did not change when synthesized on the filter paper; however, the surface of MIL-88A became rough and amorphous after Co doping. The Co-M88A-FP/P...

Wind energy’s rapid expansion has led to unintended consequences for wildlife, with migratory bats among the species most at risk. The behavioural mechanisms underlying collisions remain poorly understood, but one hypothesis is that bats are attracted to wind turbine structures. Vision is important to bat orientation and obstacle avoidance, yet it has been relatively understudied in the context of bat–turbine interactions. We hypothesize that light reflected off turbine surfaces could attract bats, acting as a sensory pollutant that may increase collision risk. To test whether reflective...

Cross-laminated timber (CLT) is increasingly used in multi-story construction due to its structural efficiency and sustainability. However, the fire performance of CLT floor-to-wall connections remains a critical concern, particularly in balloon-frame construction, where there are complex interactions between the steel and timber components and fire-induced degradation of both materials can compromise structural integrity. This study, part of the WOODWISE project, examines the fire behaviour of CLT floor-to-wall connections through large-scale compartment fire tests. The research evaluates...

Over the past decade, several large-scale fire tests have been conducted by research teams across the world to evaluate the fire performance of mass timber structures to support the adoption of larger and taller mass timber structures. However, the tests conducted to date have a mobile fuel load of 680 MJ/m² or less. Additionally, the mobile fuel load used was often cellulose-based and made of either wood furniture or wood cribs. The WOODWISE project aims to enhance the understanding of fire dynamics in mass timber structures with the inclusion of modern mobile fuels and higher fuel loads....

The influence on fire growth from varying the amount of exposed timber at both the wall and ceiling has been studied through completion of room-scale fire tests, utilizing test standard NFPA 286, Fire Tests for Evaluating Contribution of Wall and Ceiling lnterior Finish to Room Fire Growth. Three tests were completed that had exposed timber consistent with the 2021 International Building Code (IBC). To understand the impacts on early fire growth conditions, four additional tests with exposed timber at the ceiling consisting of 40%, 60%, 80% and 100% of the floor area, were conducted....

In the United States, timber is a common building material in low and medium-rise construction, up to 25.9m (85ft). Through research and innovation, code changes were enacted in 2021 that eliminated barriers to high-rise mass timber buildings. However, some stakeholders have observed that major technical barriers remain. Specifically, the structural performance of timber during all phases of a fire and resulting emissions from buildings using combustible construction. This paper summarizes a multi-disciplinary research program designed to address the challenges in a holistic and systematic...