Large‐scale, dynamic transformations in fuel moisture drive wildfire activity across southeastern Australia

Nolan, Rachael H.; Boer, Matthias M.; Dios, Víctor Resco de; Caccamo, Gabriele; Bradstock, Ross A.

doi:10.1002/2016gl068614

Cited by 179 publications

(164 citation statements)

References 39 publications

(91 reference statements)

Supporting

Mentioning

145

Contrasting

Unclassified

Order By: Relevance

“…, Nolan et al. ). The most limiting step for fire propagation is the moisture content of dead fine fuel, but this is beyond the control of the plant and will not be covered further here.…”

Section: Fire Resistance At Individual Tree Levelmentioning

confidence: 98%

“…However, studies on thresholds for fire occurrence report important increases in burned area as live fuel moisture content (LFMC) in fine live fuels (<3 mm thick, mainly leaves and twigs) drops below 100% in southeastern Australian forests (Nolan et al. ) and below 70% in Mediterranean shrublands (Dennison et al. , Jurdao et al.…”

Section: Fire Resistance At Individual Tree Levelmentioning

confidence: 99%

See 1 more Smart Citation

Fire‐induced deforestation in drought‐prone Mediterranean forests: drivers and unknowns from leaves to communities

Karavani

Boer

Baudena

et al. 2018

Ecological Monographs

113

View full text Add to dashboard Cite

Over the past 15 years, 3 million hectares of forests have been converted into shrublands or grasslands in the Mediterranean countries of the European Union. Fire and drought are the main drivers underlying this deforestation. Here we present a conceptual framework for the process of fire‐induced deforestation based on the interactive effects of fire and drought across three hierarchical scales: resistance in individuals, resilience in populations, and transitions to a new state. At the individual plant level, we review the traits that confer structural and physiological resistance, as well as allow for resprouting capacity: deforestation can be initiated when established individuals succumb to fire. After individuals perish, the second step toward deforestation requires a limited resilience from the population, that is, a reduced ability of that species to regenerate after fire. If individuals die after fire and the population fails to recover, then a transition to a new state will occur. We document trade‐offs between drought survival and fire survival, as embolism resistance is negatively correlated with fire tolerance in conifers and leaf shedding or drought deciduousness, a process that decreases water consumption at the peak of the dry season, temporally increases crown flammability. Propagule availability and establishment control resilience after mortality, but different hypotheses make contrasting predictions on the drivers of post‐fire establishment. Mycorrhizae play an additional role in modulating the response by favoring recovery through amelioration of the nutritional and water status of resprouts and new germinants. So far, resprouter species such as oaks have provided a buffer against deforestation in forests dominated by obligate seeder trees, when present in high enough density in the understory. While diversifying stands with resprouters is often reported as advantageous for building resilience, important knowledge gaps exist on how floristic composition interacts with stand flammability and on the “resprouter exhaustion syndrome,” a condition where pre‐fire drought stress, or short fire return intervals, seriously restrict post‐fire resprouting. Additional attention should be paid to the onset of novel fire environments in previously fire‐free environments, such as high altitude forests, and management actions need to accommodate this complexity to sustain Mediterranean forests under a changing climate.

show abstract

“…, Nolan et al. ). The most limiting step for fire propagation is the moisture content of dead fine fuel, but this is beyond the control of the plant and will not be covered further here.…”

Section: Fire Resistance At Individual Tree Levelmentioning

confidence: 98%

Section: Fire Resistance At Individual Tree Levelmentioning

confidence: 99%

Fire‐induced deforestation in drought‐prone Mediterranean forests: drivers and unknowns from leaves to communities

Karavani

Boer

Baudena

et al. 2018

Ecological Monographs

113

View full text Add to dashboard Cite

show abstract

“…Here, we demonstrate that the key building blocks for operational monitoring and forecasting of forest flammability already exist (Nolan et al, , ; Resco de Dios et al, ). We apply this methodology to demonstrate that the severe forest fires of 17–22 June 2017 in central Portugal, near the town of Pedrogão Grande, erupted when the predicted moisture content of forest fuels in the area and across much of the country's forest regions exceeded critical thresholds for major fire activity (Figure ).…”

Section: Forest Fire Hazard Prediction For Risk Mitigationmentioning

confidence: 99%

Changing Weather Extremes Call for Early Warning of Potential for Catastrophic Fire

et al. 2017

View full text Add to dashboard Cite

Changing frequencies of extreme weather events and shifting fire seasons call for enhanced capability to forecast where and when forested landscapes switch from a nonflammable (i.e., wet fuel) state to the highly flammable (i.e., dry fuel) state required for catastrophic forest fires. Current forest fire danger indices used in Europe, North America, and Australia rate potential fire behavior by combining numerical indices of fuel moisture content, potential rate of fire spread, and fire intensity. These numerical rating systems lack the physical basis required to reliably quantify forest flammability outside the environments of their development or under novel climate conditions. Here, we argue that exceedance of critical forest flammability thresholds is a prerequisite for major forest fires and therefore early warning systems should be based on a reliable prediction of fuel moisture content plus a regionally calibrated model of how forest fire activity responds to variation in fuel moisture content. We demonstrate the potential of this approach through a case study in Portugal. We use a physically based fuel moisture model with historical weather and fire records to identify critical fuel moisture thresholds for forest fire activity and then show that the catastrophic June 2017 forest fires in central Portugal erupted shortly after fuels in the region dried out to historically unprecedented levels.

show abstract

“…It underlines that the dryness of fuel is pivotal in the occurrence of EW and therefore urges modellers to improve our estimations of fuel moisture dynamics and mortality events (see for instance Nolan et al, 2016) …”

Section: Discussionmentioning

confidence: 99%

“…When combined, press and pulse droughts may yield 'hot droughts' (Overpeck, 2013). 5 Second, translating drought characteristics into fuel moisture content is not straightforward, because fire-prone ecosystems consist of several fuel compartments that respond to drought on different timescales (Pyne, 1996;Nolan et al, 2016). Fuel moisture of trees and shrubs live foliage responds to mid-term to long-term droughts because of the control of vegetation over water fluxes (Ruffault et al, 2013).…”

mentioning

confidence: 99%

Extreme Wildfire occurrence in response to Global Change type Droughts in the Northern Mediterranean

Ruffault¹,

Curt²,

St-Paul³

et al. 2017

Preprint

View full text Add to dashboard Cite

Abstract. Increasing drought conditions under global warming are expected to alter the frequency and distribution of large, high intensity wildfires. Yet, little is known regarding how it will affect fire weather and translate into wildfire behavior.Here, we analyzed the climatology of extreme wildfires that occurred during the exceptionally dry summers of 2003 and 2016 in Mediterranean France. We identified two distinct shifts in fire climatology towards fire weather spaces that had not been explored before, and which result from specific interactions between the types of drought and the types of fire. In 2016, 15 a long-lasting 'press drought' intensified wind-driven fires. In 2003, a 'hot drought' combining a heatwave with a press drought intensified heat-driven fires. Our findings highlight that increasing drought conditions projected by climate change scenarios might affect the dryness of fuel compartments and create several new generations of wildfire overwhelming fire suppression capacities.

show abstract

Large‐scale, dynamic transformations in fuel moisture drive wildfire activity across southeastern Australia

Cited by 179 publications

References 39 publications

Fire‐induced deforestation in drought‐prone Mediterranean forests: drivers and unknowns from leaves to communities

Fire‐induced deforestation in drought‐prone Mediterranean forests: drivers and unknowns from leaves to communities

Changing Weather Extremes Call for Early Warning of Potential for Catastrophic Fire

Extreme Wildfire occurrence in response to Global Change type Droughts in the Northern Mediterranean

Contact Info

Product

Resources

About