Treesearch

Long-term field studies are the gold standard for learning and proof-of- concept in applied forest ecology. In the northern Rocky Mountains, USA, researchers have showcased the enduring effects of fire hazard reduction and restoration treatments at the Lubrecht Fire and Fire Surrogate study. This study demonstrates the extra benefit of reduced severity to insect outbreak following mechanical treatments. Combined mechanical and fire treatments prove to have long-lasting restoration effects, including regenerating desirable tree species. Thanks to the simple design and clear results, this...

This scientific commentary refers to `Stem heating results in hydraulic dysfunction in Symplocos tinctoria: implications for post-fire tree death' by Hoffmann et al. (https://doi.org/10.1093/treephys/tpae023).How does fire kill trees? This is a fundamental question to which we surprisingly do not have the answer. The capacity to predict when and where trees will die due to fire is important for addressing a range of applied research problems, such as modelling fire effects on vegetation and dependent fauna, carbon emissions and modelling future fire regimes. As fire regimes continue to...

The US National Fire Danger Rating System (USNFDRS) supports wildfire management decisions nationwide, but it has not been updated since 1988. Here we implement new fuel moisture models, and we simplify the fuel models while maintaining the overall USNFDRS structure. Modeled and measured live fuel moisture content values were highly correlated (𝑟2 = 0.629 with defaults and 𝑟2 = 0.693 when species and location optimized). We also consolidated fuel models to five fuel types that eliminated significant index cross-correlation. Index seasonality compared between old (V2) and new USNFDRS models...

Nutrient limitation is widespread in terrestrial ecosystems. Accordingly, representations of nitrogen (N) limitation in land models typically dampen rates of terrestrial carbon (C) accrual, compared with C-only simulations. These previous findings, however, rely on soil biogeochemical models that implicitly represent microbial activity and physiology. Here we present results from a biogeochemical model testbed that allows us to investigate how an explicit versus implicit representation of soil microbial activity, as represented in the MIcrobial-MIneral Carbon Stabilization (MIMICS) and...

Background and Aims - Hotter drought- and biotically driven tree mortality are expected to increase with climate change in much of the western USA, and species persistence will depend upon ongoing establishment in novel conditions or migration to track ecological niche requirements. High-elevation tree species might be particularly vulnerable to increasing water stress as snowpack declines, increasing the potential for adult mortality and simultaneous regeneration failures. Seedling survival will be determined by ecophysiological limitations in response to changing water availability and...

Invasive annual grasses are often facilitated by fire, yet they can become ecologically dominant in susceptible locations even in the absence of fire. We used an extensive vegetation plot database to model susceptibility to the invasive annual grass cheatgrass (Bromus tectorum L.) in the sagebrush biome as a function of climate and soil water availability variables. We built random forest models predicting cheatgrass presence or dominance (>15 % relative cover) under unburned (37,219 plots) and burned conditions (6340 plots). We mapped predicted probability of cheatgrass presence and...

The recovery of biomass in secondary forests plays a vital role in global carbon sequestration processes and carbon emission mitigation. However, accurately quantifying the accumulation rate of aboveground biomass density in these forests is challenging owing to limited longitudinal field data. An alternative monitoring strategy is characterizing the mean biomass at a single point in time across stands with a range of known ages. This chronosequence approach can also be used with remotely sensed data by combining biomass measured with platforms such as NASA’s Global Ecosystem Dynamics...

As of 2023, the use of prescribed fire to manage ecosystems accounts for more than 50% of area burned annually across the United States. Prescribed fire is carried out when meteorological conditions, including temperature, humidity, and wind speed are appropriate for its safe and effective application. However, changes in these meteorological variables associated with future climate change may impact future opportunities to conduct prescribed fire. In this study, we combine climate projections with information on prescribed burning windows for ecoregions across the contiguous United States...

Wildfires are increasingly impacting social and environmental systems in the United States (US). The ability to mitigate the adverse effects of wildfires increases with understanding of the social, physical, and biological conditions that co-occurred with or caused the wildfire ignitions and contributed to the wildfire impacts. To this end, we developed the FPA FOD-Attributes dataset, which augments the sixth version of the Fire Program Analysis Fire-Occurrence Database (FPA FOD v6) with nearly 270 attributes that coincide with the date and location of each wildfire ignition in the US. FPA...

Panelists discussed the development and use of a research strategy to cultivate communities of practice for the mitigation of risks associated with the catastrophic effects of wildfires on communities. Two primary goals of the authors were to: (a) contribute theoretically to the understanding and application of communities of practice, specifically around risk management and (b) contribute to understanding in the form of lessons learned from the United States Forest Service.