Research Database
Displaying 21 - 40 of 124
Climate influences on future fire severity: a synthesis of climate-fire interactions and impacts on fire regimes, high-severity fire, and forests in the western United States
Year: 2023
Background
Increases in fire activity and changes in fire regimes have been documented in recent decades across the western United States. Climate change is expected to continue to exacerbate impacts to forested ecosystems by increasing the frequency, size, and severity of wildfires across the western United States (US). Warming temperatures and shifting precipitation patterns are altering western landscapes and making them more susceptible to high-severity fire. Increases in large patches of high-severity fire can result in significant impacts to landscape processes and ecosystem function…
Publication Type: Journal Article
Building water resilience in the face of cascading wildfire risks
Year: 2023
Severe wildfire is altering the natural and the built environment and posing risks to environmental and societal health and well-being, including cascading impacts to water systems and built water infrastructure. Research on wildfire-resilient water systems is growing but not keeping pace with the scale and severity of wildfire impacts, despite their intensifying threat. In this study, we evaluate the state of knowledge regarding wildfire-related hazards to water systems. We propose a holistic framework to assess interactions and feedback loops between water quality, quantity, and…
Publication Type: Journal Article
Rapid fuel recovery after stand-replacing fire in closed-cone pine forests and implications for short-interval severe reburns
Year: 2023
Accelerating disturbance activity under a warming climate increases the potential for multiple disturbances to overlap and produce compound effects that erode ecosystem resilience — the capacity to experience disturbance without transitioning to an alternative state. A key concern is the potential for amplifying or attenuating feedbacks via interactions among successive, linked disturbance events. Following severe wildfires, fuel limitation is a negative feedback that may reduce the likelihood of subsequent fire. However, the duration of, and pre-fire vegetation effects on fuel limitation…
Publication Type: Journal Article
Mechanical thinning restores ecological functions in a seasonally dry ponderosa pine forest in the inland Pacific Northwest, USA
Year: 2023
An increasingly important goal of federal land managers in seasonally dry forests of the western US is restoring forest resilience. In this study, we quantified the degree to which a thinning treatment in a dry forest of eastern Oregon restored aspects of forest resilience by focusing on key functional attributes of our study system. First, we measured several physiological responses of overstory trees that are associated with resilience, including radial growth, resin production, abundance of non-structural carbohydrates (NSC), and leaf area. Second, we investigated understory vegetation…
Publication Type: Journal Article
A roadmap for pyrodiversity science
Year: 2023
Background
Contemporary and projected shifts in global fire regimes highlight the importance of understanding how fire affects ecosystem function and biodiversity across taxa and geographies. Pyrodiversity, or heterogeneity in fire history, is often an important driver of biodiversity, though it has been largely overlooked until relatively recently. In this paper, we synthesise previous research to develop a theoretical framework on pyrodiversity–biodiversity relationships and propose future research and conservation management directions.
Theoretical Framework
Pyrodiversity may affect…
Publication Type: Journal Article
Consistent spatial scaling of high-severity wildfire can inform expected future patterns of burn severity
Year: 2023
Increasing wildfire activity in forests worldwide has driven urgency in understanding current and future fire regimes. Spatial patterns of area burned at high severity strongly shape forest resilience and constitute a key dimension of fire regimes, yet remain difficult to predict. To characterize the range of burn severity patterns expected within contemporary fire regimes, we quantified scaling relationships relating fire size to patterns of burn severity. Using 1615 fires occurring across the Northwest United States between 1985 and 2020, we evaluated scaling relationships within fire…
Publication Type: Journal Article
Ability of seedlings to survive heat and drought portends future demographic challenges for five southwestern US conifers
Year: 2023
Climate change and disturbance are altering forests and the rates and locations of tree regeneration. In semi-arid forests of the southwestern USA, limitations imposed by hot and dry conditions are likely to influence seedling survival. We examined how the survival of 1-year seedlings of five southwestern US conifer species whose southwestern distributions range from warmer and drier woodlands and forests (Pinus edulis Engelm., Pinus ponderosa Douglas ex C. Lawson) to cooler and wetter subalpine forests (Pseudotsuga menziesii (Mirb.) Franco, Abies concolor…
Publication Type: Journal Article
Shaded fuel breaks create wildfire-resilient forest stands: lessons from a long-term study in the Sierra Nevada
Year: 2023
Background In California’s mixed-conifer forests, fuel reduction treatments can successfully reduce fire severity, bolster forest resilience, and make lasting changes in forest structure. However, current understanding of the duration of treatment effectiveness is lacking robust empirical evidence. We leveraged data collected from 20-year-old forest monitoring plots within fuel treatments that captured a range of wildfire occurrence (i.e., not burned, burned once, or burned twice) following initial plot establishment and overstory thinning and prescribed fire treatments. Results Initial…
Publication Type: Journal Article
Fire-regime variability and ecosystem resilience over four millennia in a Rocky Mountain subalpine watershed
Year: 2023
- Wildfires strongly influence forest ecosystem processes, including carbon and nutrient cycling, and vegetation dynamics. As fire activity increases under changing climate conditions, the ecological and biogeochemical resilience of many forest ecosystems remains unknown.
- To investigate the resilience of forest ecosystems to changing climate and wildfire activity over decades to millennia, we developed a 4800-year high-resolution lake-sediment record from Silver Lake, Montana, USA (47.360° N, 115.566° W). Charcoal particles, pollen grains, element concentrations and stable…
Publication Type: Journal Article
The outsized role of California’s largest wildfires in changing forest burn patterns and coarsening ecosystem scale
Year: 2023
Highlights • We evaluated trends for 1,809 fires that burned 1985–2020 across California forests. • Top 1% of fires by size burned 47% of total area burned across the study period. • Top 1% (18 fires) produced 58% of high and 42% of low-moderate severity area. • Top 1% created novel landscape patterns of large burn severity patches. • These large fires create new opportunities for managing forest resilience. Although recent large wildfires in California forests are well publicized in media and scientific literature, their cumulative effects on forest structure and implications for forest…
Publication Type: Journal Article
Community Forests advance local wildfire governance and proactive management in British Columbia, Canada
Year: 2023
As wildfires are increasingly causing negative impacts to communities and their livelihoods, many communities are demanding more proactive and locally driven approaches to address wildfire risk. This marks a shift away from centralized governance models where decision-making is concentrated in government agencies that prioritize reactive wildfire suppression. In British Columbia (BC), Canada, Community Forests—a long-term, area-based tenure granted to Indigenous and/or local communities—are emerging as local leaders facilitating proactive wildfire management. To explore the factors that are…
Restoration and Hazardous Fuel Reduction, Risk Assessment and Analysis, Social and Community Impacts of Fire
Publication Type: Journal Article
Less fuel for the next fire? Short-interval fire delays forest recovery and interacting drivers amplify effects
Year: 2023
As 21st-century climate and disturbance dynamics depart from historic baselines, ecosystem resilience is uncertain. Multiple drivers are changing simultaneously, and interactions among drivers could amplify ecosystem vulnerability to change. Subalpine forests in Greater Yellowstone (Northern Rocky Mountains, USA) were historically resilient to infrequent (100–300 year), severe fire. We sampled paired short-interval (<30-year) and long-interval (>125-year) post-fire plots most recently burned between 1988 and 2018 to address two questions: (1) How do short-interval fire, climate,…
Publication Type: Journal Article
Terrestrial carbon dynamics in an era of increasing wildfire
Year: 2023
In an increasingly flammable world, wildfire is altering the terrestrial carbon balance. However, the degree to which novel wildfire regimes disrupt biological function remains unclear. Here, we synthesize the current understanding of above- and belowground processes that govern carbon loss and recovery across diverse ecosystems. We find that intensifying wildfire regimes are increasingly exceeding biological thresholds of resilience, causing ecosystems to convert to a lower carbon-carrying capacity. Growing evidence suggests that plants compensate for fire damage by allocating carbon…
Publication Type: Journal Article
Cultivating Collaborative Resilience to Social and Ecological Change: An Assessment of Adaptive Capacity, Actions, and Barriers Among Collaborative Forest Restoration Groups in the United States
Year: 2022
Collaboration is increasingly emphasized as a tool to realize national-level policy goals in public lands management. Yet, collaborative governance regimes (CGRs) are nested within traditional bureaucracies and are affected by internal and external disruptions. The extent to which CGRs adapt and remain resilient to these disruptions remains under-explored. Here, we distill insights from an assessment of the Collaborative Forest Landscape Restoration Program (CFLRP) projects and other CGRs. We asked (1) how do CGRs adapt to disruptions? and (2) what barriers constrained CGR resilience? Our…
Publication Type: Journal Article
Incorporating place-based values into ecological restoration
Year: 2022
Knowledge of how ecocultural landscapes co-evolved, how they were shaped and maintained by local people, and what processes disturbed the landscape should inform the planning, execution, and significance of restoration projects. Indigenous stewardship has resulted in legacies of diverse and productive ecocultural environments. Often, this stewardship has been guided by place-based values, which are informed by Indigenous knowledge, beliefs of equal respect for all ecosystem components, and conduct that sustains resource productivity. We propose that cultivating place-based values in…
Publication Type: Journal Article
Cognition of feedback loops in a fire-prone social-ecological system
Year: 2022
Increasing wildfire severity highlights the need for large-scale shifts in management of fire-prone landscapes. While prior research has focused on cognitive biases, social norms, and institutional disincentives that limit reform, such factors are best understood as components of feedback loops that operate within complex adaptive systems. We evaluated the prominence and function of feedback loops embedded in cognitive maps—beliefs about patterns of causal relationships that drive system dynamics—elicited from a diverse cross-section of stakeholders in a fire-prone region in the U.S. West. We…
Publication Type: Journal Article
Reimagine fire science for the anthropocene
Year: 2022
Fire is an integral component of ecosystems globally and a tool that humans have harnessed for millennia. Altered fire regimes are a fundamental cause and consequence of global change, impacting people and the biophysical systems on which they depend. As part of the newly emerging Anthropocene, marked by human-caused climate change and radical changes to ecosystems, fire danger is increasing, and fires are having increasingly devastating impacts on human health, infrastructure, and ecosystem services. Increasing fire danger is a vexing problem that requires deep transdisciplinary, trans-…
Publication Type: Journal Article
Disturbance and Sustainability in Forests of the Western United States
Year: 2021
This report assesses recent forest disturbance in the Western United States and discusses implications for sustainability. Individual chapters focus on fire, drought, insects, disease, invasive plants, and socioeconomic impacts. Disturbance data came from a variety of sources, including the Forest Inventory and Analysis program, Forest Health Protection, and the National Interagency Fire Center. Disturbance trends with the potential to affect forest sustainability include altera-tions in fire regimes, periods of drought in some parts of the region, and increases in invasive plants, insects,…
Publication Type: Journal Article
Where and why do conifer forests persist in refugia through multiple fire events?
Year: 2021
Changing wildfire regimes are causing rapid shifts in forests worldwide. In particular, forested landscapes that burn repeatedly in relatively quick succession may be at risk of conversion when pre-fire vegetation cannot recover between fires. Fire refugia (areas that burn less frequently or severely than the surrounding landscape) support post-fire ecosystem recovery and the persistence of vulnerable species in fire-prone landscapes. Observed and projected fire-induced forest losses highlight the need to understand where and why forests persist in refugia through multiple fires. This…
Publication Type: Journal Article
Wildfire and climate change adaptation of western North American forests: a case for intentional management
Year: 2021
Forest landscapes across western North America (wNA) have experienced extensive changes over the last two centuries, while climatic warming has become a global reality over the last four decades. Resulting interactions between historical increases in forested area and density and recent rapid warming, increasing insect mortality, and wildfire burned areas, are now leading to substantial abrupt landscape alterations. These outcomes are forcing forest planners and managers to identify strategies that can modify future outcomes that are ecologically and/or socially undesirable. Past forest…
Publication Type: Journal Article