As climatic changes continue to drive increases in the frequency and severity of forest fires, it is critical to understand all of the factors influencing the risk of forest fire. Using a spatial dataset of areas burnt over a 65 year period in a 528 343 ha study area, we examined three possible drivers of flammability dynamics. These were: that forests became more flammable as fine biomass (fuel) returned following disturbance (H1), that disturbance increased flammability by initiating dense understorey growth that later self-thinned (H2), and that climatic effects were more important than either of these internal dynamics (H3). We found that forests were unlikely to burn for a short ‘young’ period (5–7 years) following fire, very likely to burn as the regrowing understorey became taller and denser (regrowth period), then after a total post-disturbance period of 43–56 years (young + regrowth periods), fire became unlikely and continued to decrease in likelihood (mature period). This trend did not change as the climate warmed, although increases in synoptic variability (mean changes in synoptic systems per season) had a pronounced effect on wildfire likelihood overall. Young forest and regrowth forest became increasingly likely to burn in years of greater synoptic variability and the time taken for forests to mature increased, but in years with the most severe synoptic variability, mature forests were the least likely to burn. Our findings offer an explanation for fire behaviour in numerous long-term studies in diverse forest types globally and indicate that, even in the face of a warming climate, ‘ecologically-cooperative’ approaches may be employed that reinforce rather than disrupt natural ecological controls on forest fire. These range from traditional indigenous fire knowledge, to modern targeting of suppression resources to capitalise on the benefits of self-thinning, and minimise the extent of dense regrowth in the landscape.

Self-thinning forest understoreys reduce wildfire risk, even in a warming climate

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

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1111/1365-2435.14305

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

\n OCBIL theory is a multi-hypothesis formulation aimed towards an understanding of the evolution, ecology and conservation of biological and cultural diversity on old, climatically buffered, infertile landscapes (OCBILs). OCBILs have been in existence contemporaneously with rainforest since Gondwanan times. Such landscapes are common in areas of eucalypt species richness embraced by Australia’s two Global Biodiversity Hotspots, the Southwest Australian Floristic Region and the Forests of East Australia. Here, I summarize evidence pertaining to the eucalypts in the context of a recent reformulation of OCBIL theory into 12 evolutionary, ecological and cultural hypotheses and ten conservation management hypotheses. A compelling argument emerges for a new interpretation of the eucalypts evolving out of the OCBILs, rather than out of the rainforests as traditionally interpreted. This calls for a significant reinterpretation of best conservation management of the eucalypts. For example, traditional ideas on application of fire in eucalypt communities regarded as well adapted to this disturbance need to give way to a more nuanced and cautious view. This review of eucalypts seen as evolving out of the OCBILs helps in understanding the group from several new perspectives. Interpretation of other sedentary plant and animal groups as out of the OCBILs is commended for further study.

Out of the OCBILs: new hypotheses for the evolution, ecology and conservation of the eucalypts

Abstract Wildfire risk-management needs to consider interrelated factors that influence fire regimes, including changing climate and sometimes conflicting stakeholder priorities. With wildfires increasing in size and intensity over recent decades, wildfire risk management is becoming more important and more complex. For southwest Australia, wildfire risk-management is predicated on a longitudinal study of the relationship between prescribed burns and wildfires from 1953–2004 over a subset of this biodiverse region. Our study replicates the methodology of the longitudinal study, applying it to the wider region and extending the analysis to 2021. We found the extrapolation of the longitudinal study’s findings to the wider region invalid, as was extrapolation beyond 2004. In particular, the area of prescribed burns generally had negligible influence on wildfire area. However, more spatially complex fire history was strongly correlated with lower probability of large wildfires (independent of area burned). This highlights the limitation of extrapolating wildfire risk-management policies to areas of differing vegetation and/or climate, including changing climate over time. The potential of indigenous-led practices for wildfire risk and biodiversity conservation, particularly for areas with high spatial variability, is apparent as is the need for alternative strategies to prescribed burning as the primary tool in wildfire-risk mitigation.

https://www.tandfonline.com/doi/pdf/10.1080/19475705.2022.2119891?needAccess=true

Wildfire risk management across diverse bioregions in a changing climate

and desire for continuation of youth empowerment programs in conservation. To facilitate gender equity in Aboriginal natural and cultural resource management, structural and sus-tained support of women’s empowerment and leadership, driven by local women with sup- port of local communities, is required.

Empowering young Aboriginal women to care for Country: Case study of the Ngukurr
 Yangbala
 rangers, remote northern Australia

\n Occurring across all southern hemisphere continents except Antarctica, old, climatically buffered, infertile landscapes (OCBILs) are centres of biological richness, often in biodiversity hotspots. Among a matrix of young, often disturbed, fertile landscapes (YODFELs), OCBILs are centres of endemism and diversity in the exceptionally rich flora of the south-west Australian global biodiversity hotspot, home to Noongar peoples for ≥ 48 000 years. We analysed contemporary traditional Noongar knowledge of adjacent OCBILs (e.g. granite outcrops) and YODFELs (e.g. creekline fringes) both at a single site and in two larger areas to test whether patterns of disturbance dictated by Noongar custom align with OCBIL theory. We found that Noongar traditional knowledge reflects a regime of concentrated YODFEL rather than OCBIL disturbance—a pattern which aligns with maximal biodiversity preservation. SIMPER testing found traditional Noongar OCBIL and YODFEL activities are 64–75% dissimilar, whereas Pearson’s chi-square tests revealed camping, burning, travelling through country and hunting as primarily YODFEL rather than OCBIL activities. We found that Noongar activities usually avoid OCBIL disturbance. This combined with high floristic diversity following enduring First Peoples’ presence, suggests that traditional Noongar knowledge is valuable and necessary for south-west Australian biodiversity conservation. Similar cultural investigations in other OCBIL-dominated global biodiversity hotspots may prove profitable.

The Noongar of south-western Australia: a case study of long-term biodiversity conservation in a matrix of old and young landscapes

High gene flow and a population structure corresponding to human rather than geographical drivers are likely to be genetic patterns of human-dispersed plant taxa. We examined variation in geographical structure and gene flow estimates based on three non-coding regions of plastid DNA in three south-west Australian members of the Platysace genus to identify whether a human influence on dispersion of utilized taxa was detectable. Edible tubers of Platysace deflexa and Platysace trachymenioides have been harvested historically by Noongar traditional owners, whereas Platysace effusa has no known cultural significance. We found differences between utilized and non-utilized taxa, particularly when considered against the generally complex phylogeographical patterning in south-west Australian plant taxa. Platysace effusa showed a pattern of high population divergence, low gene flow and multiple refugia, consistent with a long evolutionary history, past climatic oscillations and persistence in a highly fragmented landscape. In contrast, higher gene flow estimates, less divergence between populations and common haplotypes in P. deflexa and in P. trachymenioides over the south-eastern part of its range are consistent with anthropogenic influences. This study contributes to the understanding of human influences on south-west Australian plant taxa that have been present since the late Pleistocene, but to date have received little scientific attention.

Platysace (Apiaceae) of south-western Australia: silent story tellers of an ancient human landscape

Contemporary distribution of Macrozamia dyeri (Zamiaceae) is correlated with patterns of Nyungar occupation in south‐east coastal Western Australia

\n Geophytes are a considerable component of Southwest Australian flora and thus, unsurprisingly, feature heavily in the diets and culture of Noongar First Nations people of this old, climatically buffered, infertile landscape-dominated global biodiversity hotspot. Of ~650 geophyte species recorded in south-western Australia, 90 are known traditional Noongar foods. Despite the significant role of geophytes in Noongar traditional lives, there is little published knowledge of the ecological effects of harvesting geophytes. We measured and observed soil and plant outcomes of tuber harvest for two Noongar staple species of Platysace Bunge to test whether it improved soil conditions for plant growth and/or aided tuber availability, as suggested for other Australian Aboriginal root crops. Harvesting of Platysace deflexa led to increases in some soil nutrient levels and, unexpectedly, to an increase in bulk density. Platysace deflexa stem abundance was restored to the pre-harvest level within 1 year post-harvest, whereas tuber weight and volume were less than pre-harvest levels after 2 years. A post-harvest increase in the proportion of small tubers in crops suggests that harvest has a renewing and homogenizing effect on tubers. Site-based differences in post-harvest P. deflexa and Platysace trachymenioides quantity of tubers were consistent with preferential harvest of some populations by present-day Noongar families and their ancestors.

Soil and plant outcomes of harvesting a Noongar staple geophyte in south-western Australia

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Lynette Knapp

Author Tools

Chat about Author

Papers

The Noongar of south-western Australia: a case study of long-term biodiversity conservation in a matrix of old and young landscapes

Platysace (Apiaceae) of south-western Australia: silent story tellers of an ancient human landscape

Contemporary distribution of Macrozamia dyeri (Zamiaceae) is correlated with patterns of Nyungar occupation in south‐east coastal Western Australia

Soil and plant outcomes of harvesting a Noongar staple geophyte in south-western Australia