Treesearch

Whitebark pine (Pinus albicaulis, WBP) is an important high-elevation conifer in the Western USA that was listed as ‘‘threatened’’ under the Endangered Species Act in 2023. Consequently, land managers are tasked with ensuring the longterm viability of WBP populations through conservation and restoration efforts. The effects of mountain pine beetle (Dendroctonus ponderosae, MPB) outbreaks on WBP dynamics are poorly understood, especially for smaller-diameter trees that typically escape attack due to their size, allowing for persistence in the understory through outbreak events. Here, we...

Fire has played a driving role in the speciation and evolution of the genus Pinus (pines) and continues to exert dominant influences on Pinus-dominated forests around the world. This chapter is divided into two major sections: fire ecology and fire ecophysiology. In the fire ecology section, we review fire-adapted traits of Pinus that allow persistence and recovery after fire, including how traits cluster to form fire syndromes. Fire regimes are described as an emergent property of fire syndromes and climate. In the fire ecophysiology section, we review the effects of fire on Pinus carbon...

The spatial patterns of fire effects and tree mortality have profound consequences for forest resilience. Costeffective, medium-resolution, and spatiotemporally extensive fire severity measurements are essential for informing post-fire restoration and improving our understanding of wildfires—from forest stands to continents and from days to decades. Remote sensing advancements have improved burn severity mapping, but methods vary in interpretability, scalability, generalizability, and alignment with field measurements. One meaningful metric of fire effects on forests is proportion basal...

To make strategic decisions about safety and resource allocation, managers must understand when prescribed burn windows of opportunity occur, how they vary throughout the year, and how to anticipate them. For two burn types—pile and broadcast—we characterize the temporal and spatial distributions of past “go-burn” days identified from a database of 15,468 burn permits from 2011 to 2024 in the Northern California Geographic Area Coordination Center’s region. We assess the mean temporal evolution of daily anomalies of local- and synoptic-scale environmental variables that occurred in the 2...

Burned area and wildfire damages in the western United States (WUS) have increased dramatically in recent decades. Wildfire frequency, however, has shown trends that vary by data set, region, and fire size. Using a comprehensive fire occurrence data set screened for reporting artifacts from 1992 to 2020, we show a significant downward trend in annual fire frequency in WUS, with a significant contribution from decreasing human ignitions. Human‐caused fires significantly declined in California and Arizona, but increased in Wyoming. The relationship between human‐caused fires and population...

The extent of alpine land cover influences the chemistry of streams draining mountain catchments and may determine how they respond to ecosystem change. During the first two decades of the 2000s, the Southern Rockies, USA, experienced both severe bark beetle infestation and significant decreases in atmospheric nitrogen (N) and sulfur (S) deposition. To evaluate the consequences of these events, we compared the chemistry of samples collected during 2004–2006 and 2017–2019 in streams draining 18 headwater catchments comprised of mixtures of forest and alpine land cover. Stream total dissolved...

Have you ever looked at a towering ponderosa pine forest and wondered how old the trees are? Were all the trees of a similar age, known as an “even-aged structure,” such as often results from a reforestation effort where all the seedlings were planted at the same time. Or were there a mixture of young and old trees? That sort of “multi-aged structure” in ponderosa pine forests is desirable as it can meet many of the goals of multi-use land management. A forest stand with different-aged trees can support timber production, livestock grazing, recreation opportunities, wildlife habitat, and...

The Blue Mountains ecoregion of eastern Oregon, encompassing the Malheur, Umatilla, and Wallowa–Whitman National Forests, faces escalating wildfire risk driven by historical fire exclusion and fuel accumulation. This study integrates spatially explicit fuel reduction and restoration treatment planning with mass timber production to simultaneously enhance fire resilience and stimulate rural economic development. Using TreeMap 2022 data and potential operational delineations, we found that 69% of forests exceed fire-resilient desired future conditions, with 31% prioritized as potential...

Human actions, whether deliberate (e.g., fire suppression) or indeliberate (e.g., anthropogenic climate change), have and will continue to detrimentally impact wilderness ecosystems. These human-induced stressors are significantly degrading and even imperil the natural qualities of many wilderness areas (see Shive et al. 2026 ). Yet contemporary wilderness management philosophies, which arose in an era that predated rapid and ubiquitous environmental stressors such as climate change, may limit our ability to protect the natural conditions of these places.

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The rising frequency of large-scale, destructive wildfires has significantly affected not only natural ecosystems but also critical infrastructure, human lives, and properties. Given the devastating and often irreversible environmental and financial consequences, researchers from diverse fields are actively seeking solutions to improve resilience against wildfires. Fire suppression, one of the most effective strategies to mitigate wildfire damage, relies heavily on rapid and high-fidelity forecasting of fire spread. These predictions are essential for planning evacuations by state or local...