Chapter 7 : Forests. Fifth National Climate Assessment

Published: Jan. 1, 2023

Language: Английский

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A Statistical Forecasting Model for Extremes of the Fire Behaviour Index in Australia

Atmosphere, Journal Year: 2024, Volume and Issue: 15(4), P. 470 - 470

Published: April 10, 2024

The increasing frequency and duration of severe fire events in Australia further necessitate accurate timely forecasting to mitigate their consequences. This study evaluated the performance two distinct approaches extreme danger at two- three-week lead times for period 2003 2017: official Australian climate simulation dynamical model a statistical based on drivers. We employed linear logistic regression develop model, assessing influence individual drivers using single regression. both models was through case studies three significant Australia: Canberra (2003), Black Saturday (2009), Pinery (2015) fires. results revealed that ACCESS-S2 generally underestimated spatial extent all FBI events, but with accuracy scores ranging from 0.66 0.86 across studies. Conversely, tended overpredict area affected by FBI, high false alarm ratios between 0.44 0.66. However, demonstrated higher probability detection scores, 0.57 0.87 compared 0.03 dynamic model. These findings highlight complementary strengths limitations approaches. Integrating transparent communication uncertainties could potentially improve reduce alarms. can be achieved hybrid forecasting, combined visual inspection comparison forecasts. Hybrid also has potential increase forecast up several months, ultimately aiding decision-making resource allocation management.

Language: Английский

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Climate and fire drivers of forest composition and openness in the Changbai Mountains since the Late Glacial

Forest Ecosystems, Journal Year: 2023, Volume and Issue: 10, P. 100127 - 100127

Published: Jan. 1, 2023

Ongoing climate changes have a direct impact on forest growth; they also affect natural fire regimes, with further implications for composition. Understanding of how these will forests decadal-to-centennial timescales is limited. Here we use reconstructions past vegetation, regimes and during the Holocene to examine relative importance in abundance key tree species northeastern China. We reconstructed vegetation based pollen charcoal records from Gushantun peatland. then used generalized linear modelling investigate summer temperature, annual precipitation, background levels fire, frequency magnitude identify drivers openness Changes independent impacts taxa. Climate variables are generally more important than determining individual Precipitation only determinant openness, but temperature precipitation taxa warmer summers causing decrease cold-tolerant conifers an increase warmth-demanding broadleaved trees. Both level negative relationships most taxa; Pinus increases as increases. The fires does not significant this timescale. regime characteristics must be considered understand composition There differences, both sign magnitude, response drivers.

Language: Английский

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Second-Entry Burns Reduce Mid-Canopy Fuels and Create Resilient Forest Structure in Yosemite National Park, California

Forests, Journal Year: 2022, Volume and Issue: 13(9), P. 1512 - 1512

Published: Sept. 17, 2022

Understanding the patterns and underlying drivers of forest structure is critical for managing landscape processes multiple resource management. Merging several landscape-scale datasets, including long-term fire histories, airborne LiDAR, downscaled topo-climatic data, we assessed complex ecological questions regarding interactions structure, climate, in Yosemite National Park, a protected area historically dominated by frequent largely free impacts commercial industrial logging. We found that broadly corresponded with types arranged across elevation-driven climatic gradients repeated burning shifts towards conditions are consistent increased resilience, biodiversity, ecosystem health function. Specifically, all types, tree density mid-canopy strata cover was significantly reduced compared to overstory canopy indices improved after two fires, but no additional change occurred subsequent burns. This study provides valuable information managers who seek refine prescriptions based on an enhanced understanding fire-mediated changes ladder fuels those seeking define number treatments needed mitigate severe risk enhance resiliency fires. In addition, our highlights utility large-landscape LiDAR acquisitions supporting fire, forest, wildlife management prioritization wildfire assessments numerous valued resources.

Language: Английский

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Landscape patterns in stand-replacing disturbances across the world’s forests

Nature Sustainability, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 15, 2024

Abstract The spatial imprint of forest disturbances, which can result from a variety anthropogenic and natural causes, is important in shaping the form function world’s forests. However, we lack systematic assessment how forms disturbances differ globally, could help sustainable policy management initiatives to protect biomes. Here produce global-scale quantification disturbance patch structures. Using indicators magnitude, complexity context, found that stand-replacing be classified into four broad patterns, whose dominance varies across regions. Human activities were shown introduce structures are not naturally common, especially tropics. consistency these patterns biomes outside intact forests suggests continuation current dynamics may lead structural homogenization forests, with potential consequences for ecology functions. These results provide greater understanding mechanisms governing elucidating causal agents disturbances. This will key step towards building more reliable projections future conditions, informing policymaking ensuring sustainability management.

Language: Английский

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Decadal Fire Effects on the Structure, Composition and Aboveground Carbon Stocks of a Neotropical Savanna

Published: Aug. 2, 2023

Fire is a common disturbance in the Brazilian savanna (Cerrado), wherein high-frequency fires drive vegetation structure, composition, function, and dynamics of ecosystems. Under climate change pressure, further understanding fire-vegetation relationships interactions can provide new approaches for establishing strategies integrated fire management promote recovery post-fire. To understand how 15 years yearly manipulated burning affects vertical horizontal structure vegetation, species composition diversity metrics (species richness, Shannon's diversity, Pielou's evenness), aboveground carbon stocks, we surveyed all woody plant with diameter greater than three centimeters plots typical (cerrado stricto sensu) at an experimental research station central Brazil (Cerrado biome). Fifteen (five per treatment) were differently affected by events over decade, comprising treatments: (i) annual fire, (ii) legacy (> 11 since last event), control (not burned past 30 years). Non-metric multidimensional scaling (NMDS) analysis indicated significant effect on among treatments that some benefited from such as Erythroxylum suberosum, whereas others propagated better without Camisala montana Dalbergia miscolobium. Over decade led to decreases stem density, which significantly lower treatment treatments. Stem density height size class (except 1-2 m above 8 m) was higher treatment, but number dead trees did not differ between Our results also showed factor changes evaluated parameters, reduced amount biomass and, therefore, stock. This study suggests that, if yearly, savannas become less biodiverse terms negatively affect their resilience. Therefore, practices should focus determining frequency these ecosystems may benefit most disturbances.

Language: Английский

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Decadal Fire Effects on the Structure, Composition, Diversity, and Aboveground Carbon Stocks of a Neotropical Savanna

Forests, Journal Year: 2023, Volume and Issue: 14(12), P. 2294 - 2294

Published: Nov. 23, 2023

Fire is a common disturbance in the Brazilian savanna (the cerrado), wherein high-frequency fires drive vegetation structure, composition, function, and dynamics of ecosystems. Under climate change pressure, further understanding fire–vegetation relationships interactions can provide new approaches for establishing integrated fire management strategies promote post-fire recovery. To understand how 15 years annually manipulated burning has affected vertical horizontal structures vegetation, species composition diversity metrics (species richness, Shannon’s diversity, Pielou’s evenness), aboveground carbon stocks, we surveyed all woody plant with diameter greater than three centimeters, plots typical (cerrado stricto sensu) at an experimental research station central Brazil cerrado biome). The (five per treatment) had been differently by events over decade, comprised treatments: (i) annual fire, (ii) legacy (>15 since last event), (iii) control (not burned past 30 years). A non-metric multidimensional scaling (NMDS) analysis indicated that significant effect on among treatments; some benefited from such as Erythroxylum suberosum, whereas other propagated better without Roupala montana Dalbergia miscolobium. Over decade have led to decreases stem density, which were significantly lower treatment treatments. Stem density height size classes (except 1–2 m class above 8 class) was higher treatment, but number dead trees did not differ between treatment. Our results also showed factor changes evaluated parameters, where reduced amount biomass, therefore stocks. This study suggests that, if yearly, savannas become less biodiverse terms negatively affects their resilience. Therefore, practices should focus determining frequency disturbances these ecosystems may benefit most.

Language: Английский

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