Contemporary wildfires are more severe compared to the historical reference period in western US dry conifer forests

Forest Ecology and Management, Год журнала: 2023, Номер 544, С. 121232 - 121232

Опубликована: Июль 3, 2023

Язык: Английский

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Forest restoration and fuels reduction work: Different pathways for achieving success in the Sierra Nevada

Ecological Applications, Год журнала: 2023, Номер 34(2)

Опубликована: Ноя. 10, 2023

Abstract Fire suppression and past selective logging of large trees have fundamentally changed frequent‐fire‐adapted forests in California. The culmination these changes produced that are vulnerable to catastrophic change by wildfire, drought, bark beetles, with climate exacerbating this vulnerability. Management options available address problem include mechanical treatments (Mech), prescribed fire (Fire), or combinations (Mech + Fire). We quantify forest structure composition, fuel accumulation, modeled behavior, intertree competition, economics from a 20‐year restoration study the northern Sierra Nevada. All three active (Fire, Mech, Mech Fire) conditions were much more resistant wildfire than untreated control. included lowest surface duff loads hazards. low hazards beginning 7 years after initial treatment had lower tree growth controls. only competition somewhat similar historical California mixed‐conifer was Fire, indicating stands under would likely be resilient enhanced stressors. While reduced hazard reintroduced fundamental ecosystem process, it done at net cost landowner. Using mastication thinning resulted positive revenues also relatively strong as an investment reducing hazard. represents compromise between desire sustain financial feasibility reintroduce fire. One key component long‐term conservation will continued maintain improve restoration. Many Indigenous people speak “active stewardship” one principles land management aligns well need for increased western US forests. If we do not use knowledge 20+ research longer tradition cultural practices knowledge, frequent‐fire continue degraded lost.

Язык: Английский

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A scalable and transferable approach to combining emerging conservation technologies to identify biodiversity change after large disturbances

Journal of Applied Ecology, Год журнала: 2024, Номер 61(4), С. 797 - 808

Опубликована: Янв. 31, 2024

Abstract Ecological disturbances are becoming more extensive and intensive globally, a trend exemplified by ‘megafires’ industrial deforestation, which cause widespread losses of forest cover. Yet the hypothesis that contemporary environmental affecting biodiversity has been difficult to test directly. The novel combination landscape‐scale passive acoustic monitoring, new machine learning algorithm, BirdNET improved Bayesian model‐fitting engines enables cohesive, community‐level before‐after, control‐impact studies disturbances. We conducted such study 2020 megafire in Sierra Nevada, USA. used bespoke dynamic multi‐species occupancy modelling approach, enabled us account for imperfect detection, misclassifications, share information among species. There was no difference colonization between burned unburned forest. In contrast, probability site extinction forest, 0.36, significantly higher than 0.12. Of 67 species our study, 6 (9%) displayed positive response fire, while 28 (41%) significant response. observed 12% decrease avian 1 year post‐fire, substantial shift community composition. However, this ecosystem, many display time‐dependent responses fire unobservable after just year. Synthesis applications . have shown three emerging conservation technologies, animal sound identification algorithms, advances statistical tools, can provide previously unattainable about ecological change. Critically, approach is transferrable scalable, as workflow agnostic or ecosystem each component either freely available (all relevant software) relatively inexpensive (recording hardware). Environmental change unfolding rapidly, but analytical techniques may help understanding and—thus interventions—keep pace.

Язык: Английский

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Strategic fire zones are essential to wildfire risk reduction in the Western United States

Fire Ecology, Год журнала: 2024, Номер 20(1)

Опубликована: Май 21, 2024

Abstract Background Over the last four decades, wildfires in forests of continental western United States have significantly increased both size and severity after more than a century fire suppression exclusion. Many these historically experienced frequent were fuel limited. To date, reduction treatments been small too widely dispersed to impacted this trend. Currently new land management plans are being developed on most 154 National Forests that will guide support ground practices for next 15–20 years. Results During plan development, we recommend Strategic Fire Zones (SFZs) be identified large blocks (≥ 2,000 ha) Federal forest lands, buffered 1–2.4 km) from wildland-urban interface reintroduction beneficial fire. In SFZs, lightning ignitions, as well prescribed cultural burns, would used reduce fuels restore ecosystem services. Although such successfully established limited number Parks Wilderness Areas, identify extensive remote areas US (8.3–12.7 million ha), outside wilderness (85–88%), where they could established. Potential wildland Operational Delineations or PODs SFZ boundaries. We outline steps identify, implement, monitor, communicate use benefits SFZs. Conclusions Enhancing collaboration knowledge-sharing with Indigenous communities can play vital role gaining agency public building narrative how rebuild climate-adapted regimes live within them. Meaningful increases multiply amount landscape while reducing risk their impacts structures

Язык: Английский

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‘Mind the Gap’—reforestation needs vs. reforestation capacity in the western United States

Frontiers in Forests and Global Change, Год журнала: 2024, Номер 7

Опубликована: Май 29, 2024

Tree establishment following severe or stand-replacing disturbance is critical for achieving U.S. climate change mitigation goals and maintaining the co-benefits of intact forest ecosystems. In many contexts, natural post-fire tree regeneration sufficient to maintain cover associated ecosystem services, but increasingly pattern scale exceeds ecological thresholds active reforestation may be warranted. Our capacity plant trees, however, not keeping pace with needs. This shortfall uniquely apparent in western U.S., where wildfire size severity have increased recent decades long-term divestment supply chain has limited our ability respond existing Here we present an analysis key facets both demand side address six questions: (1) What current backlog potential needs driven by high-severity wildfire?; (2) How will increasing activity through end century affect needs?; (3) meet future (4) can demands?; (5) approaches promote resilience (6) Where are opportunities emerging from policy initiatives, innovative public-private partnerships, capital markets scaling reforestation? Between 1984 2000, annual planting met cumulatively over last two (2000 2021) it fallen short fire-driven estimated 1.5 million ha ( ca. 3.8 ac). We anticipate this gap increase 2 3 fold 2050. Scaling up efforts close require investment across all chain, novel that forests drought wildfire. highlight initiatives conservation finance expanding efforts.

Язык: Английский

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Biogeographic patterns of daily wildfire spread and extremes across North America

Frontiers in Forests and Global Change, Год журнала: 2024, Номер 7

Опубликована: Май 27, 2024

Introduction Climate change is predicted to increase the frequency of extreme single-day fire spread events, with major ecological and social implications. In contrast well-documented spatio-temporal patterns wildfire ignitions perimeters, daily progression remains poorly understood across continental spatial scales, particularly for events (“blow ups”). Here, we characterize North America, including occurrence duration seasonality extremes, ecoregional climatic niches in terms Actual Evapotranspiration (AET) Climatic Water Deficit (CWD) annual climate normals. Methods Remotely sensed 9,636 wildfires ≥400 ha was used growth, duration, seasonality. To explore occurrence, extent, impacts extremes among ecoregions, considered complementary thresholds (Ecoregional or Continental Mean Daily Area Burned + 2SD). Ecoregional rates were regressed against AET CWD influence on spread. Results We found three-fold differences mean 10 American ranging from 260 day −1 Marine West Coast Forests 751 Mediterranean California. ranged 3,829 16,626 , relative a threshold 7,173 . The ~3% classified as cumulatively account 16–55% total area burned ecoregions. observed four-fold 2.7 days Great Plains 10.5 Northwestern Forested Mountains. Regions shorter durations also had greater burned, suggesting paradigm fast-growing short-duration fires some regions slow-growing long-duration elsewhere. weak positive relationship rate thresholds, there no pattern AET. Discussion Although conditions can set stage ignition vegetation fuels, finer-scale mechanisms likely drive variation offers valuable insights into regional seasonal distributions how these shape net effects.

Язык: Английский

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Post-Fire Burned Area Detection Using Machine Learning and Burn Severity Classification with Spectral Indices in İzmir: A SHAP-Driven XAI Approach

Fire, Год журнала: 2025, Номер 8(4), С. 121 - 121

Опубликована: Март 21, 2025

This study was conducted to precisely map burned areas in fire-prone forest regions of İzmir and analyze the spatial distribution wildfires. Using Sentinel-2 satellite imagery, burn severity first classified using dNBR dNDVI indices. Subsequently, machine learning (ML) algorithms—RF, XGBoost, LightGBM, AdaBoost—were employed classify unburned areas. To enhance model performance, hyperparameter optimization applied, results were evaluated multiple accuracy metrics. found that RF achieved highest with an overall 98.0% a Kappa coefficient 0.960. In comparison, classification based solely on spectral indices resulted accuracies 86.6% (dNBR) 81.7% (dNDVI). A key contribution this is integration Explainable Artificial Intelligence (XAI) through SHapley Additive exPlanations (SHAP) analysis, which used interpret influence environmental variables area classification. SHAP analysis made decision processes transparent identified dNBR, dNDVI, SWIR/NIR bands as most influential variables. Furthermore, analyses confirmed variations reflectance across fire-affected are critical for accurate delineation, particularly heterogeneous landscapes. provides scientific framework post-fire ecosystem restoration, fire management, disaster strategies, offering decision-makers data-driven effective intervention strategies.

Язык: Английский

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Quail on fire: changing fire regimes may benefit mountain quail in fire-adapted forests

Fire Ecology, Год журнала: 2023, Номер 19(1)

Опубликована: Апрель 3, 2023

Fire-adapted forests in western North America are experiencing rapid changes to fire regimes that outside the range of historic norms. Some habitat-specialist species have been negatively impacted by increases large, high-severity fire, yet, responses many especially at longer time scales, remain ambiguous. We studied response a widely distributed species, mountain quail (Oreortyx pictus), wildfire across Sierra Nevada California, because its habitat selection patterns provided an opportunity evaluate potentially contrasting among specialists. used passive acoustic monitoring > 22,000 km2 and Bayesian hierarchical occupancy modeling conduct first study effects habitat, severity, since (1–35 years) on little-understood management indicator quail. Mountain responded positively neutrally low-moderate-severity fire. Occupancy peaked 6–10 years after remained high even 11–35 area burned severity. Our work demonstrates is strongly related occupancy, which markedly different than previously also concern Nevada. Taken together, our results suggest may actually be "winners" face altered Given forecasted intensification severe wildfires fire-adapted forests, understanding ecology nuanced beyond those historically considered important time-sensitive effort. The relationship between reminder there will both winners losers as dynamics change era climate change.

Язык: Английский

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Estimating population size for California spotted owls and barred owls across the Sierra Nevada ecosystem with bioacoustics

Ecological Indicators, Год журнала: 2023, Номер 154, С. 110851 - 110851

Опубликована: Авг. 27, 2023

Monitoring population size at ecosystem scales is difficult for most species of conservation concern. While assessing site occupancy broad has proven feasible, rigorous tracking changes in over time not – even though it can provide a stronger basis status and conservation-decision making. Therefore, we demonstrate how relatively low-intensity, ecosystem-scale passive acoustic monitoring (PAM) be linked to local-density estimate the native California spotted owls (Strix occidentalis occidentalis) invasive barred (S. varia) across western Sierra Nevada, California. Based on PAM sampling grid with 400 ha cells (the approximate home range these species), estimated between 0.42 (SE = 0.02) 0.30 using liberal strict criteria, respectively, considering cell occupied. PAM-based estimates within local-scale density study areas (range 0.41–0.78 0.28–0.76 respectively) were strongly positively correlated local 0.08–0.31 owl/km2) this species. In contrast, ecosystem-wide was very low based (0.034, SE < 0.01), as densities studies 0–0.005 owls/km2). By scaling studies, that, depending 2,218 278) or 2,328 489) occurred Nevada 2021. Thus, while are rare subspecies, they well-distributed Nevada. Because there so few owl detections, could abundance, which reflects success prior experimental removals region. conclusion, our provides generalizable framework estimating territorial when available. that approach novel valuable insights into populations aid conservation.

Язык: Английский

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Active management: a definition and considerations for implementation in forests of temperate Australia

Australian Forestry, Год журнала: 2024, Номер 87(3), С. 125 - 147

Опубликована: Июль 2, 2024

Active management is often mentioned but rarely defined in current policies and strategies for native forests of temperate Australia. Lack clarity about active could mean that to support forest health human involvement with are not fit purpose. In this paper, we summarise the policy context Victoria (as a case study Australia) review representations broader temperate-forest literature, including its place relation associated concepts like adaptive management. Based on review, provide definition focuses activities – deliberate practices diverse purposes goals situated within operational approaches (e.g. frameworks) enact overarching philosophy paradigm(s) Our acknowledges multiple potential framings encompass philosophies sociocultural relationships require governance structures foster inclusive understandings. Additional considerations implementing Australia's include refreshed visions management, clearly stated criteria choosing among under uncertainty, revised guidelines practices, commitment building evidence base through iterative learning targeted experiments an or analogous framework.

Язык: Английский

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