Treesearch

Background. Terrain-induced turbulence is dangerous for smokejumpers parachuting into complex terrain and results in numerous serious accidents annually. Aims. We quantify wind modelling system WindNinja’s ability to reproduce terrain-induced effects on the mean wind speed and turbulence in complex terrain. We assess WindNinja’s suitability for use in identifying safe jump spots during smokejumper operations in complex terrain. Methods. We evaluate the model’s ability to reproduce mean wind speed, mean wind direction and turbulence kinetic energy (TKE) measured by sonic anemometers and...

Wood densification, aimed at enhancing mechanical properties through compression, faces challenges due to set-recovery, where densified wood regains its original shape upon re-moistening. However, understanding the role of lignin in set-recovery remains elusive. In this study, acidified sodium chlorite was applied to achieve approximately 50 % delignification without removing other wood components from 3.2 mm veneers of birch, aspen, and grey alder. The veneers were then densified at 100◦C and 6 MPa, with wood moisture contents (MC) of 10 % and 16 %. The morphology, physical properties,...

Wildfire in Hawaiʻi is increasing due to the interacting factors of land-use history, invasive grass species, shifting climates, and increasing ignitions. Native plant restoration and green breaks offer viable solutions to decrease invasive grass biomass and thus the fine fuels that often carry wildfire. While some organizations and agencies have robust inhouse plant materials programs, there is still a lack of readily available materials for varied stakeholders to meet their management objectives across the state. We briefly outline the current state of the wildfire crisis in Hawaiʻi, why...

Reforestation activities such as tree planting are important management tools to offset carbon emissions and restore forest ecosystem integrity. Severe wildfire activity, a key driver of forest loss, is increasing throughout the western United States (US) and creating an immense backlog of areas needing reforestation. Major financial investments and recent policy changes are expected to accelerate rates of tree planting, yet the broad-scale impact and efficacy of post-fire planting activities remain poorly understood. We quantified the outcomes of recent (1987-2022) post-fire plantings in...

Brown root rot disease (BRRD) is a highly destructive tree disease. Early diagnosis of BRRD has been challenging because the first symptoms and signs are often observed after extensive tissue colonization. Existing molecular detection methods, all based on the internal transcribed spacer (ITS) region, were developed without testing against global Phellinus noxius isolates, other wood-decay fungi, or host plant tissues. This study aimed to develop SYBR Green real-time quantitative PCR (qPCR) assays for P. noxius. The primer pair Pn_ITS_F/Pn_ITS_R targets the ITS, and the primer pair...

Introducing new genes and new species into ecosystems where they have not previously existed presents opportunities and complex, multivalue decisions for conservation biologists and the public. Both synthetic biology and conservation introductions offer potential benefits, such as avoiding extinctions and restoring ecological function, but also carry risks of unintended ecological consequences and raise social and moral concerns. Although the conservation community has attempted to establish guidelines for each new tool, there is a need for comprehensive principles that will enable...

Boreal peatlands store abundant carbon (C) belowground because of saturated conditions and cold temperatures, which inhibit the enzymatic release of dissolved organic carbon (DOC) from organic matter. However, metals may also bind DOC, as well as nitrogen (N) and phosphorus (P), and their impact may vary among peatlands with differing hydrology. To assess variation of metal-C-nutrient interactions within and among peatlands and with depth, we sampled cores from seven peatlands in the Marcell Experimental Forest, Minnesota, including bogs, poor fens, and a rich fen. We extracted peat with...

Natural climate solutions (NCS) play a critical role in climate change mitigation. NCS can generate win–win co-benefits for biodiversity and human well-being, but they can also involve trade-offs (co-impacts). However, the massive evidence base on NCS co-benefits and possible trade-offs is poorly understood. We employ large language models to assess over 2 million published journal articles, primarily written in English, finding 257,266 relevant studies on NCS co-impacts. Using machine learning methods to extract data (for example, study location, species and other key variables), we...

Snowpacks are changing in northeastern North America as the regional climate warms, yet the relative influence of changes in precipitation compared to changes in ablation on snowpacks is poorly understood. We use 56 years of weekly snow water equivalent (SWE) measurements from three locations within a study site which vary in elevation and aspect, paired with adjacent daily climate measurements, to investigate relationships between climate and snowpack onset, maximum, and disappearance. Maximum snowpack size and snowpack duration are shrinking at all sites, at rates ranging from 4.3...

Our objective in the present study is to provide fundamental insights into the main factors that control the thermal degradation processes occurring inside the biomass vegetation during wildland fire spread. These processes determine the formation of flammable volatiles through pyrolysis reactions and the intensity of the internal heat release through char oxidation reactions; both aspects are central to flaming and smoldering combustion. We adopt here a simplified framework in which the biomass vegetation is viewed as a population of discrete elongated particles that are made of pine...