Treesearch

Area burned by wildfire has increased in western US forests and elsewhere over recent decades coincident with warmer and drier fire seasons. However, high-severity fire - fire that kills all or most trees - is arguably a more important metric of fire activity given its destabilizing influence on forest ecosystems and direct and indirect impacts to human communities. Here, we quantified area burned and area burned severely in western US forests from 1985 to 2022 and evaluated trends through time. We also assessed key relationships between area burned, extent and proportion burned severely,...

Accurate prediction of forest fire spread is a critical management and scientific challenge as the world adapts to rapidly changing fire regimes. We reconstructed 5,400 daily burned area progression maps for 196 U.S. Northern Rocky Mountain wildfires (2012-2021) and used machine learning to estimate daily fire growth given local weather, hydroclimate, fuels and topography. Optimized models explained 36% of the variation in daily fire growth, increasing to 56% when an index of fire activity the previous day was included. Soil moisture and plant hydraulic stress were the dominant predictors...

The rising introduction of invasive species through trade networks threatens biodiversity and ecosystem services. Yet, we have a limited understanding of how transportation networks determine spatiotemporal patterns of range expansion. This knowledge gap may stem from two reasons. First, current analytical models fail to integrate the invader’s life-history dynamics with heterogeneity in human-mediated dispersal patterns. Second, classical statistical methods often fail to provide reliable estimates of model parameters, such as the time and place of species introduction and life-history...

Fire regimes are context-dependent, as are the ways that animals respond. However, most information on animal responses to fire comes from short-term local field studies, which are hard to extrapolate across large areas for fire management while also capturing spatial variation. To address this challenge, we modeled data from eBird to map the direction, magnitude, and importance of fire regime associations at 27-km resolution across the ranges of six bird species used to guide management decisions in the US: red-cockaded woodpecker (Leuconotopicus borealis), Bachman's sparrow (Peucaea...

Climate change is reducing the extent of cold aquatic habitats and their unique biodiversity in mountain areas. However, a variety of cold rocky landforms (CRLs) are thermally buffered and feed cold springs (<2 °C) that may represent climate refugia for cold-adapted organisms. These landforms, hitherto overlooked by freshwater research, include rock glaciers, debris-covered glaciers, talus slopes, protalus ramparts, and young moraines. Here, we investigated the warm-season water temperature of 228 springs from clean (ice) glaciers, CRLs, and reference slopes (not sourced by any of these...

Lamprey molecular phylogenies to date have relied on mitochondrial (mt) DNA sequence data, and there has long been recognition that a robust molecular phylogeny of this ancient group of vertebrates - with relatively few phylogenetically informative morphological characters - will require the use of a wider range of genes, particularly nuclear genes (e.g., Lang et al. 2009; Potter et al. 2015; Docker and Hume 2019). Hughes et al. (2025) performed this long awaited phylogenomic analysis to assess phylogenetic relationships of lampreys, and estimated divergence time and diversification rates...

Understanding thermal stress in tropical forests has taken on new urgency in light of accelerating climate change and expansion of deforestation and forest degradation. Degraded tropical forests in particular may be approaching critical temperature thresholds even more rapidly than intact forests, with implications for tree survival and ecosystem recovery. We investigate thermal stress in degraded tropical forests within the Brazilian Amazon Arc of Deforestation. Using land surface temperature data from the ECOsystem Spaceborne Thermal Radiometer Experiment on the international Space...

Despite fire being one of the oldest and most important ecological disturbance processes on Earth, many aspects of fire–vegetation feedbacks are poorly understood, limiting their accurate representation in predictive models. Translating plant flammability traits to fire behavior and fire effects on ecosystems has proven a challenge with different disciplines approaching the problem at widely different scales. One approach has been a top-down assessment of ecosystem-level effects of vegetation structural characteristics and plant physiology on fuel properties such as fuel moisture. This...

National forest inventory (NFI) data are often costly to collect, which inhibits efforts to estimate parameters of interest for small spatial, temporal, or biophysical domains. Traditionally, design-based estimators are used to estimate status of forest parameters of interest, but are unreliable for small areas where data are sparse. Additionally, design-based estimates constructed directly from the survey data are often unavailable when sample sizes are especially small. Traditional model-based small area estimation approaches, such as the Fay-Herriot (FH) model, rely on these direct...

Wildfire is a natural disturbance in landscapes of the Western United States, but the effects and extents of fire are changing. Differences between historical and contemporary fire regimes can help identify reasons for observed changes in landscape composition. People living and working in the Great Basin, USA, are observing altered fire conditions, but spatial information about the degree and direction of change and departure from historical fire regimes is lacking. This study estimates how fire regimes have changed in the major Great Basin vegetation types over the past 60 years with...