Shifting fire regimes cause continent-wide transformation of threatened species habitat

Proceedings of the National Academy of Sciences, Год журнала: 2024, Номер 121(18)

Опубликована: Апрель 22, 2024

Human actions are causing widespread increases in fire size, frequency, and severity diverse ecosystems globally. This alteration of regimes is considered a threat to numerous animal species, but empirical evidence how shifting within both threatened species’ ranges protected areas scarce, particularly at large spatial temporal scales. We used big data approach quantify multidecadal changes southern Australia from 1980 2021, spanning 415 reserves (21.5 million ha) 129 including birds, mammals, reptiles, invertebrates, frogs. Most the region have experienced declines unburnt vegetation (≥30 y without fire), recently burnt (≤5 since frequency. The mean percentage declined 61 36% (1980 2021), whereas increased 20 35%, frequency by 32%, with latter two trends primarily driven record-breaking 2019 2020 season. strongest occurred for high-elevation high elevation, productivity, strong rainfall decline, southeast continent. Our results provide widely held poorly tested assumption that species experiencing habitat underscores imperative developing management strategies conserve fire-threatened an increasingly fiery future.

Язык: Английский

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Slope and equilibrium: A parsimonious and flexible approach to model microclimate

Methods in Ecology and Evolution, Год журнала: 2023, Номер 14(3), С. 885 - 897

Опубликована: Янв. 3, 2023

Abstract Most statistical models of microclimate focus on the difference or ‘offset’ between standardized air temperatures (macroclimate) and those a specific habitat such as forest understorey, grassland under log. However, these offsets can fluctuate from positive to negative over single day that common practice consists in aggregating data into daily mean, minimum maximum before modelling monthly for each summary statistic. Here, we propose more parsimonious flexible approach relying just two parameters: slope equilibrium. The captures linear relationship macroclimate, while equilibrium is point at which equals macroclimate. Although applicable other habitats, demonstrate relevance our method by focusing understoreys. We installed temperature sensors 1‐m height inside stands nearby open grasslands equipped with weather stations, across 13 sites France spanning wide climatic gradient. From year hourly sensor, established relationships macroclimate using mixed‐effects models, during leaf‐on (May–November) leaf‐off period (December–April). extracted used another set investigate their main determinants. was chiefly determined stand structure variables interacting leaf‐on/leaf‐off period: type (conifer vs broadleaf); shade‐casting ability; age; dominant height; stem density; cover upper lower shrub layer. In contrast, had no explanatory power found be positively related mean temperature, open/forest habitat. introduced here overcomes several shortcomings offsets. By demonstrating vary predictable ways, have general linkage applied any location time if know (equilibrium) buffering amplifying capacity (slope). also warn about methodological biases due reference

Язык: Английский

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From broadleaves to conifers: The effect of tree composition and density on understory microclimate across latitudes

Agricultural and Forest Meteorology, Год журнала: 2023, Номер 341, С. 109684 - 109684

Опубликована: Сен. 4, 2023

Forest canopies buffer the macroclimate and thus play an important role in mitigating climate-warming impacts on forest ecosystems. Despite importance of tree layer for understory microclimate buffering, our knowledge about effects structure, composition their interactions with is limited, especially mixtures conifers broadleaves. Here we studied five mixed stands along a 1800 km latitudinal gradient covering 7°C span mean annual temperature. In each these forests established 40 plots (200 total), which air soil temperatures were measured continuously at least one year. The located across gradients density broadleaved proportions (i.e. from open to closed canopies, 100% conifer dominance). Air minimum, maximum temperature offsets difference between microclimate) calculated coldest warmest months. density, was key determinant temperatures. However, absolute relative proportion broadleaves differed largely response variables. ranged being independent of, interacting with, species composition. effect two variables gradient. Temperature, precipitation, snow depth wind outside affected buffering. Finally, found that scale overstory affects approximated 6-7 m, whereas this 10 m. These findings have implications biodiversity conservation management changing climate, as they facilitate projection scenarios where both structure are dynamic. This relevant given global ongoing conversion broadleaves, vice versa.

Язык: Английский

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Identifying and managing disturbance‐stimulated flammability in woody ecosystems

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Год журнала: 2023, Номер 99(3), С. 699 - 714

Опубликована: Дек. 17, 2023

ABSTRACT Many forest types globally have been subject to an increase in the frequency of, and area burnt by, high‐severity wildfire. Here we explore role that previous disturbance has played increasing extent severity of subsequent fires. We summarise evidence documenting explaining mechanisms underpinning a pulse flammability may follow disturbances such as fire, logging, clearing or windthrow (a process term disturbance‐stimulated flammability). Disturbance sometimes initiates short initial period low flammability, but then drives extended increased vegetation regrows. Our analysis initially focuses on well‐documented cases Australia, also discuss where these pattens apply elsewhere, including Northern Hemisphere. outline by which through disrupting ecological controls limit it undisturbed forests. develop test conceptual model aid prediction woody communities patterns occur. interaction with climate change, is driving larger more severe current state knowledge around point disturbed, fire‐prone stands are sufficiently widespread landscapes they promote spatial contagion wildfire overwhelms any reduction fire spread offered less‐flammable stands. how land managers might deal major challenges changes landscape cover altered regimes created. This especially pertinent now dominated extensive areas young regenerating after regrowing following broadscale prescribed burning, agricultural abandonment. Where found stimulate key management actions should consider long‐term benefits of: ( i ) limiting disturbance‐based like logging burning creates forests triggers understorey development; ii protecting from assisting them transition older, state; iii reinforcing fire‐inhibitory properties methods for rapid detection suppression.

Язык: Английский

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Mechanisms by which growth and succession limit the impact of fire in a south‐western Australian forested ecosystem

Functional Ecology, Год журнала: 2023, Номер 37(5), С. 1350 - 1365

Опубликована: Март 20, 2023

Abstract Forest wildfire impact is widely believed to increase with time since disturbance, presenting a dilemma for the persistence of fire‐sensitive species. However, in south‐western Australia, disturbance has been shown likelihood some decades before it again declines. It proposed that this trend occurs through ‘ecological controls’ on such as self‐thinning fire‐stimulated understorey growth. Here, we analyse six ecological controls using surveyed chronosequence Eucalyptus jacksonii forest community. We quantify plant growth (growth and self‐pruning) succession (changing traits, self‐thinning), along consequent changes surface suspended litter. then use biophysical, mechanistic model predict dynamics flame height canopy scorch/consumption, suppression difficulty during conditions. To identify importance each potential control, separately manipulate them grow hypothetical forests from 1 100 years; one removed. compare original had all present. Fire initially promoted dense regeneration, but transferred biomass fuel (likely ignite) overstorey shelter (unlikely ignite, creating less flammable microclimate). The effect these was alter modelled fire behaviour, dimensions mature were half those regrowth, damage greatly reduced, opportunities maximised. primary self‐pruning. explains observed trends flammability Australian forests, species over time. Approaches cooperate with, rather than disrupt, processes therefore provide pathway mitigate current climatic effects fire. Read free Plain Language Summary article Journal blog.

Язык: Английский

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Forest temperature buffering in pure and mixed stands: A high-resolution temporal analysis with generalized additive models

Forest Ecology and Management, Год журнала: 2025, Номер 583, С. 122582 - 122582

Опубликована: Фев. 25, 2025

Язык: Английский

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Quantifying drivers of decline: A case study of long-term changes in arboreal marsupial detections

Biological Conservation, Год журнала: 2024, Номер 293, С. 110589 - 110589

Опубликована: Апрель 17, 2024

Using a 26-year dataset, we quantify temporal change in detections of arboreal marsupial species the tall, wet montane ash forests mainland south-eastern Australia. We sought to determine if patterns number were associated with changes potential explanatory variables, such as stand age and abundance hollow-bearing trees. Our key findings were: (1) Four characterised by an overall decline over time, although sometimes complex, non-linear ways. Exceptions Common Ringtail Possum (Pseudocheirus peregrinus) which increased, Mountain Brushtail (Trichosurus cunninghami) exhibited no change. (2) Detections almost all strongly related (3) Long-term declines most trees age. And, (4) There strong interspecific effects, ranging from negative associations young regenerated forest after wildfire 2009 for Southern Greater Glider (Petauroides volans), positive same aged Possum. underscore that management must properly address drivers decline. Management protect promote recruitment large old keystone resource marsupials. results also highlight substantial lag effects condition resulting past clearfelling recurrent wildfires has led widespread degradation. Active, long-term restoration programs will be needed this problem.

Язык: Английский

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Microclimate variation and recovery time in managed and old-growth temperate forests

Agricultural and Forest Meteorology, Год журнала: 2023, Номер 342, С. 109722 - 109722

Опубликована: Сен. 22, 2023

Язык: Английский

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Topography influences diurnal and seasonal microclimate fluctuations in hilly terrain environments of coastal California

PLoS ONE, Год журнала: 2024, Номер 19(3), С. e0300378 - e0300378

Опубликована: Март 29, 2024

Understanding the topographic basis for microclimatic variation remains fundamental to predicting site level effects of warming air temperatures. Quantifying diurnal fluctuation and seasonal extremes in relation topography offers insight into potential relationship between conditions changes regional climate. The present study investigated an annual understory temperature regime 50 sites distributed across a topographically diverse area (>12 km2) comprised mixed evergreen-deciduous woodland vegetation typical California coastal ranges. We effect tree cover on site-to-site near-surface temperatures using combination multiple linear regression multivariate techniques. Sites depressed areas (e.g., valley bottoms) exhibited larger variation. Elevation (at 10 m resolution) was found be primary driver daily variations, addition hillslope position, canopy northness. elevation mean inverted, reflecting large-scale cold-air pooling region, with elevated minimum at higher elevations. Additionally, several our showed considerable buffering (dampened fluctuations) compared average measured on-site weather station. Results from this help inform efforts extrapolate records large landscapes have improve ecological understanding fine-scale climate range environments.

Язык: Английский

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What did it used to look like? A case study from tall, wet mainland Mountain Ash forests prior to British invasion

Austral Ecology, Год журнала: 2024, Номер 49(4)

Опубликована: Апрель 1, 2024

Abstract There has been extensive commentary about historical First Nations' land management in Australia, including tall, wet forests, and therefore their condition at the time of British invasion 1788. Popular texts have interpreted records kept by early invaders to argue that areas forest were open through frequent burning Peoples. However, these interpretations conflict with ecological evidence, which is rarely acknowledged public discourse. Here, we present evidence what Victorian Mountain Ash ( Eucalyptus regnans ) forests like invasion. We show invasion, most mainland likely naturally dense wet, with: (1) overstorey trees spaced relatively widely; (2) an understorey consisting a cool temperate rainforest mesic layer. Ecological physiological suggests evolved under conditions where high‐severity wildfire was comparatively rare, leading patterns landscape‐level cover dominated mature forests. This broadly consistent reports from Peoples, accounts, paintings, photographs. These not or park‐like, as may case some other Australian vegetation types. wilderness , but places significance Understanding structure critically important establishing reference for guiding appropriate restoration programmes, especially reinstatement traditional knowledge, after long periods post‐British disturbance degradation. Notably, dense, characterizes should be recognized inherent entirely natural part dynamics this ecosystem, approaches thin, burn, remove it highly counterproductive range detrimental environmental effects.

Язык: Английский

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