@article {bnh-7475, title = {Exploring the key drivers of forest flammability in wet eucalypt forests using expert-derived conceptual models}, journal = {Landscape Ecology}, volume = {35}, year = {2020}, month = {06/2020}, pages = {1775{\textendash}1798}, abstract = {

Context

Fire behaviour research has largely focused on dry ecosystems that burn frequently, with far less attention on wetter forests. Yet, the impacts of fire in wet forests can be high and therefore understanding the drivers of fire in these\ systems\ is vital.

Objectives

We sought to identify and rank by importance the factors plausibly driving flammability in wet eucalypt forests, and describe relationships between them. In doing so, we formulated a set of research priorities.

Methods

Conceptual models of forest flammability in wet eucalypt forests were elicited from 21 fire experts using a combination of elicitation techniques. Forest flammability was defined using fire occurrence and fireline intensity as measures of ignitability and heat release rate, respectively.

Results

There were shared and divergent opinions about the drivers of flammability in wet eucalypt forests. Widely agreed factors were drought, dead fine fuel moisture content, weather and topography. These factors all influence the availability of biomass to burn, albeit their effects and interactions on various dimensions of flammability are poorly understood. Differences between the models related to lesser understood factors (e.g. live and coarse fuel moisture, plant traits, heatwaves) and the links between factors.

Conclusions

By documenting alternative conceptual models, we made shared and divergent opinions explicit about flammability in wet forests. We identified four priority research areas: (1) quantifying drought and fuel moisture thresholds for fire occurrence and intensity, (2) modelling microclimate in dense vegetation and rugged terrain, (3) determining the attributes of live vegetation that influence forest flammability, (4) evaluating fire management strategies.

}, keywords = {Cognitive mapping, Conceptual models, Expert elicitation, Fire behaviour, fire intensity, flammability, Structured decision-making, Structured expert judgement, Wet forest, Wildfire}, doi = {https://doi.org/10.1007/s10980-020-01055-z}, url = {https://link.springer.com/article/10.1007/s10980-020-01055-z}, author = {Jane Cawson and Victoria Hemming and Ackland, A and Wendy R. Anderson and David Bowman and Ross Bradstock and Brown, T and Jamie Burton and Geoffrey J. Cary and Thomas Duff and Alex Filkov and Furlaud, James M. and Tim Gazzard and Kilinc, Musa and Petter Nyman and Ross Peacock and Mike Ryan and Jason J. Sharples and Gary J. Sheridan and Tolhurst, K.G. and Tim Wells and Phil Zylstra and Trent Penman} } @article {bnh-7708, title = {Leaf traits predict global patterns in the structure and flammability of forest litter beds}, journal = {Journal of Ecology}, year = {2020}, month = {12/2020}, abstract = {
  1. Fallen plant material such as leaves, needles and branches form litter beds which strongly influence fire ignition and spread. Traits of the dominant species influence litter flammability directly by determining how individual leaves burn and indirectly through the structure of the litter bed. However, we are yet to determine the relative importance of these different drivers across a range of plant species from different biomes.
  2. We undertook a meta-analysis, combining leaf trait, litter structure and flammability data for 106 species from North America, South America, Europe, Asia and Australia. The dataset encompassed broad-leaved and coniferous species from seven different experimental studies. Relationships between leaf traits, litter structure and key flammability metrics{\textemdash}sustainability, combustibility and consumability{\textemdash}were analysed using bivariate and piecewise structural equation modelling (SEM).
  3. Traits which characterise the three-dimensional nature of the leaf and how much space a leaf occupies showed much stronger associations to litter structure and flammability than other morphological traits. Leaf curl, surface area to volume ratio (SAV) and SLA predominately influence litter flammability indirectly via litter structure with SLA being the only leaf trait which had a negative direct effect on flame duration. Packing ratio and bulk density were influenced by different combinations of leaf traits and, in turn, they aligned with different flammability metrics. Bulk density predicted flame spread rate and flame duration whereas packing ratio predicted consumption.
  4. Synthesis. We identified key leaf and litter traits which influence different components of litter bed flammability. Importantly, we show that the effects of these leaf and litter traits are consistent across a wide range of taxa and biomes. Our study represents a significant step towards developing trait-based models for predicting surface wildfire behaviour. Such models will more flexibly accommodate future shifts in the composition of plant species triggered by altered fire regimes and climate change.
}, keywords = {Fire behaviour, flammability, leaf traits, litter properties, meta-analysis, surface fuel}, doi = {https://doi.org/10.1111/1365-2745.13561}, url = {https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2745.13561}, author = {Jamie Burton and Jane Cawson and Alex Filkov and Trent Penman} } @mastersthesis {bnh-5779, title = {Effects of Sydney coastal dry sclerophyll forest litter on fuels and fire behaviour in Hornsby shire}, volume = {Masters of Philosophy}, year = {2019}, month = {02/2019}, school = {The University of Sydney}, type = {Masters}, address = {Sydney}, abstract = {

Globally bushfires are an ecological phenomenon that can cause deaths and widespread destruction of assets such as homes, utilities and essential infrastructure. Bushfires usually start in forest litter on a forest floor. The research described in this thesis used empirical data to characterise the physical and chemical attributes of litter, a component of forest and woodland fuels that is particularly important for propagation of fire. Differences in the amounts, arrangement and flammability of components of litter were determined for Sydney Coastal Dry Sclerophyll Forest, a common vegetation type in the Sydney Basin. Surface litter was investigated at study sites at Rofe Park, Hornsby Heights and Halls Creek, Arcadia, New South Wales, Australia.

}, keywords = {bushfires, coastal fire, flammability, litter, rubbish, Sydney, vegetation}, author = {Angela Gormley} }