Joseph Benjamin Fontaine

Extreme drought and heat are driving forest die‐off globally, yet regional‐scale mapping of subsurface water storage capacity, governing forest vulnerability, remains a major challenge. Here, we demonstrate that airborne gamma‐ray spectrometry (GRS) of potassium ( ⁴⁰ K) decay provides a powerful proxy for subsurface constraints on water availability. In southwestern Australia, we found that spatial patterns of forest die‐off during an extreme 2023–2024 drought‐heat event were strongly predicted by surficial ⁴⁰ K concentrations. While GRS measures the upper ∼30 cm of soil, plot‐scale electrical resistivity tomography suggests that elevated ⁴⁰ K signals shallow granite or gneiss bedrock, to depths reaching several tens of meters due to leaching of mobile elements, remnant bedrock minerals, erosional thinning of regolith and biological nutrient recycling from K‐rich saprolite. Airborne GRS can map forest vulnerability across highly leached landscapes, which cover one‐third of Earth's ice‐free land surface. This enables targeted adaptive management of forests for future drought‐heat intensification.

The ability of restored sites to recover from subsequent disturbances is a key component of restoration success. Resilience is achieved when a restored site returns to its pre‐disturbance state, rather than shifts to a different one. In restored fire‐prone ecosystems, the drivers of post‐fire plant responses and resilience of plant assemblages to fire are underexplored. Exploration of these responses is used to predict and measure the resilience of restored ecosystems to disturbance, including whether the disturbance response was desirable or not. We implemented fine‐scale experimental fires in a post‐mining restoration chronosequence 14–27 years of age in Banksia woodlands, Western Australia. We sought to understand the effects of restoration age, fire impact, and soil conditions on post‐fire regeneration and survival of restored Banksia woodland plant assemblages. To assess early‐stage resilience to fire, we calculated four descriptors of ecosystem state: plant species density, species diversity, rarefied richness and functional redundancy, and compared how these changed following fire across the restoration ages and in comparison to nearby reference Banksia woodland. Ordinations and indicator species analyses were used to compare restored and reference sites. In restoration sites, restoration age, fire impact and soil conditions had little effect on plant regeneration and survival. Changes in diversity, rarefied richness and functional redundancy pre‐ to post‐fire in restored sites were typically similar to or less than that observed in reference sites. Broadly, our findings demonstrate the incomplete resilience of restored Banksia woodland to fire. Resprouters typically demonstrated poor resilience, through significant decreases in diversity and rarefied richness following fire in restored sites. They were under‐represented in restored Banksia woodlands, so further investigations into the establishment of resprouters in restored environments are required. Our findings also highlight the importance of utilising reference data and a broad range of descriptors to fully understand responses of restored plant assemblages to fire.

Ticks are ectoparasites of major medical, veterinary and ecological importance, transmitting a wide range of pathogens to humans, companion animals and livestock. Understanding the population structure of ticks is essential for uncovering patterns of pathogen transmission, and population genetics provides a powerful method for this purpose. Tick population studies are uniquely challenging as their biology is shaped by complex interactions between hosts, microbiome and environmental factors. The choice of population genetic tools is crucial, as different methods offer varying levels of cost, throughput, resolution and accessibility, which can significantly influence the quality and scope of results. This review traces the evolution of molecular tools in tick population genetics, from early allozyme electrophoresis in the 1970s to advanced whole genome sequencing (WGS) technologies. It critically evaluates key methodologies, including allozyme electrophoresis, random amplified polymorphic DNA (RAPD), microsatellites (STRs), amplified fragment length polymorphisms (AFLP), sequence typing, restriction‐site associated DNA sequencing (RADseq) and WGS, highlighting their strengths, limitations and applications. By offering a practical guide to these tools, this review helps researchers select the most appropriate methods for their studies and allows interpretation of results from older tools in the context of modern research. Sequence typing and RADseq currently provide the best balance of cost and practicality, while WGS has great potential once sequencing costs decline. This resource empowers researchers to make informed decisions, maximise the impact of their work and gain deeper insights into disease vector population structure.

The time interval between fires is a critical component of the fire regime that affects plant species persistence in fire‐prone ecosystems. Fire intervals that are too short or too long may not support regeneration from seed banks or resprouting. Fire intervals that support adequate regeneration may also vary with other factors such as climate, herbivory, and population structure. Using field data on flowering and canopy seed banks, we modelled post‐fire reproduction for woody fire‐killed (obligate seeding) and resprouting species under varying rainfall and herbivory along a 35‐year fire age chronosequence in Banksia woodlands in southwestern Australia. We found that fire‐killed species attained reproductive maturity rapidly after fire with predicted juvenile periods (time to 50% flowering) of 1.5–2.3 years for shrubs and 4 years for trees. Resprouting species had similar juvenile periods to fire‐killed species (1–3.5 years for resprouting shrubs, 4.4 years for resprouting trees). Reproduction varied with rainfall and herbivory with juvenile periods at least doubling under low rainfall or high herbivory for some species. Serotinous species produced cones (woody fruits containing seeds) shortly after flowering commenced, with some evidence of seed bank decline in the oldest sites. While reproduction was clearly correlated with time since fire, plant size was a much stronger predictor. Some species form multi‐cohort populations which can introduce large variation into post‐fire reproductive trajectories, and this should be considered when making decisions about fire intervals that may impact species persistence. This study provides critical information to assess fire interval‐related threats for Banksia woodlands and suggests that woody species of these woodlands are generally tolerant of a wide range of fire intervals. Only the slowest‐maturing, fire‐killed species (Banksia prionotes, Proteaceae) may require fire intervals > 10 years to reduce immaturity risk under the least favourable growing conditions, and this species often occurs in discrete patches in the landscape such that fire management can be tailored accordingly.

Context: The concept of the fire regime is central to understanding and managing fire-prone ecosystems globally, and information on past regimes can provide useful insights into species disturbance adaptations. Although observations from satellite imagery or palaeoecological proxy data can provide direct evidence of past, pre-colonial fire regimes, they may be limited in temporal or spatial resolution and are not available for all ecosystems. However, fire-related plant-trait and demographic data offer an alternative approach to understand species–fire regime associations at the ecosystem scale. Aims: We aimed to quantify the life-history strategies and associated fire regimes for six co-occurring shrub and tree species from fire-prone, Mediterranean-climate Banksia Woodlands in south-western Australia. Methods: We collected static demographic data on size structure, seedling recruitment, and plant mortality across sites of varying time since last fire. We combined demographic data with key fire-related species traits to define plant life-history strategies. We then compared observed life histories with a priori expectations for surface, stand-replacing, and mixed-severity fire-regime types to infer historical fire-regime associations. Key results: Fire-killed shrubs and weakly serotinous trees had abundant post-fire seedling recruitment, but also developed multi-cohort populations during fire-free periods via inter-fire seedling recruitment. Resprouting shrubs had little seedling recruitment at any time, even following fire, and showed no signs of decline in the long absence of fire, likely owing to their very long lifespans. Conclusions: The variation in life-history strategies for these six co-occurring species is consistent with known ecological strategies to cope with high variation in fire intervals in a mixed-severity fire regime. Whereas resprouting and strong post-fire seedling recruitment indicate a tolerance of shorter fire intervals, inter-fire recruitment and weak serotiny are interpreted as a bet-hedging strategy to cope with occasional long fire-free periods that may otherwise exceed adult and seed-bank lifespans. Implications: Our findings suggested that Banksia Woodlands have evolved with highly variable fire intervals in a mixed-severity fire regime. Further investigations of species adaptations to varying fire size and patchiness can help extend our understanding of fire-regime tolerances.

Climate change, with warming and drying weather conditions, is reducing the growth, seed production, and survival of fire‐adapted plants in fire‐prone regions such as Mediterranean‐type ecosystems. These effects of climate change on local plant demographics have recently been shown to reduce the persistence time of local populations of the fire‐killed shrub Banksia hookeriana dramatically. In principle, extinctions of local populations may be partly compensated by recolonization events through long‐distance dispersal mechanisms of seeds, such as post‐fire wind and bird‐mediated dispersal, facilitating persistence in spatially structured metapopulations. However, to what degree and under which assumptions metapopulation dynamics might compensate for the drastically increased local extinction risk remains to be explored. Given the long timespans involved and the complexity of interwoven local and regional processes, mechanistic, process‐based models are one of the most suitable approaches to systematically explore the potential role of metapopulation dynamics and its underlying ecological assumptions for fire‐prone ecosystems. Here we extend a recent mechanistic, process‐based, spatially implicit population model for the well‐studied fire‐killed and serotinous shrub species B. hookeriana to a spatially explicit metapopulation model. We systematically tested the effects of different ecological processes and assumptions on metapopulation dynamics under past (1988–2002) and current (2003–2017) climatic conditions, including (i) effects of different spatio‐temporal fires, (ii) effects of (likely) reduced intraspecific plant competition under current conditions and (iii) effects of variation in plant performance among and within patches. In general, metapopulation dynamics had the potential to increase the overall regional persistence of B. hookeriana. However, increased population persistence only occurred under specific optimistic assumptions. In both climate scenarios, the highest persistence occurred with larger fires and intermediate to long inter‐fire intervals. The assumption of lower intraspecific plant competition caused by lower densities under current conditions alone was not sufficient to increase persistence significantly. To achieve long‐term persistence (defined as >400 years) it was necessary to additionally consider empirically observed variation in plant performance among and within patches, that is, improved habitat quality in some large habitat patches (≥7) that could function as source patches and a higher survival rate and seed production for a subset of plants, specifically the top 25% of flower producers based on current climate conditions monitoring data. Our model results demonstrate that the impacts of ongoing climate change on plant demographics are so severe that even under optimistic assumptions, the existing metapopulation dynamics shift to an unstable source‐sink dynamic state. Based on our findings, we recommend increased research efforts to understand the consequences of intraspecific trait variation on plant demographics, emphasizing the variation of individual traits both among and within populations. From a conservation perspective, we encourage fire and land managers to revise their prescribed fire plans, which are typically short interval, small fires, as they conflict with the ecologically appropriate spatio‐temporal fire regime for B. hookeriana, and likely as well for many other fire‐killed species.

In this comment we examine a recent study published in Environmental Research Letters that analysed fire history data from forests in Western Australia to suggest that changes in forest structure result in a long-term reduction of fire risk after 56 years since last fire. We examine the data underpinning this study and find that its strongly skewed sample size distribution creates a bias to the extent that the analytical approach would find a pattern of declining fire risk even when there was no decline. Moreover, the very small sample sizes of the longest unburned forests mean that fire mapping errors as small as 1–2 ha can reverse key findings. With documented mapping errors orders of magnitude larger, the dataset is not robust to analysis at this level of precision. An appropriate conclusion, taking into account these detection and sensitivity issues, would be that likelihood of subsequent wildfire is reduced in the first ∼6 years following fire, and remains fairly consistent at a higher level for at least the next 3 decades, with no evidence for a long-term reduction of fire risk. This is relevant given that many fire and forest management decisions are made based on scientific literature. Rather than wildfire risk reducing with increasing time since fire, our projections indicate that ceasing active fire management in the sampled forests could result in landscape wildfire extent 25%–65% above current levels. We recommend further steps that would help provide sound, evidence-based knowledge to inform science, management, and policy.