The research team turned to lake sediments preserved within Croajingolong National Park, one of the most repeatedly burnt landscapes in southeastern Australia, to read the region’s environmental past. Lake sediments accumulate in annual and seasonal layers, trapping charcoal particles, pollen grains and eroded soil that together form a continuous archive of what grew on the land, how hot fires burned and how severely the ground eroded across centuries. By extracting cores from the lakebed and analysing these preserved signals layer by layer, the scientists reconstructed the past 1000 years of ecological change with enough resolution to distinguish the pre-colonial period, when Gunaikurnai people actively managed the landscape, from the post-colonial era, when that management ceased. The technique allowed the researchers to separate the influence of climate variability from the influence of land use, a distinction that shorter records spanning only the industrial era cannot reliably make.

What the sediment record revealed was a cascading sequence of changes that began with fire itself. Infrared spectroscopy of charcoal fragments preserved in the sediments provided a proxy for past fire temperatures, distinguishing the cool, low-intensity burns characteristic of cultural fire practice from the hot wildfires that followed. The record shows that after colonisation, fire temperatures rose sharply. Those hotter fires came first in the sequence, and they drove a four-fold surge in eucalypt cover, transforming what had been maintained as open woodland for centuries into dense, closed forest. As the canopy thickened and fuel accumulated on the forest floor, soil erosion in the catchment increased, providing independent physical evidence that the landscape had crossed into a fundamentally more disturbed state.

Critically, the researchers demonstrated that this ecological transformation predates human-driven climate change. Dangerous fire weather is not new to East Gippsland: climate records show that seasons comparable to those that produced the Ash Wednesday fires of 1983 and the Black Saturday fires of 2009 occurred repeatedly in the region before colonisation. Yet during those earlier episodes of severe fire weather, the open woodland maintained by Gunaikurnai cultural burning did not produce catastrophic fire. The fuel loads were simply too low. It was only after colonisation ended that active management, allowing forests to expand and thicken across the region, that the same dangerous weather conditions began translating into landscape-scale disaster. In the authors’ framing, colonisation loaded the landscape with fuel, and it is that loaded landscape that has handed control of fire to the climate.

Lead author Professor Michael-Shawn Fletcher, of the School of Geography, Earth and Atmospheric Sciences at the University of Melbourne, said the work provides scientific evidence for the value of cultural burning and the need to integrate Indigenous knowledge into contemporary fire management. When Country is cared for, he noted, climate does not dictate wildfire. For thousands of years, Gunaikurnai people cared for Country in what is now Croajingolong National Park through cultural burning, keeping much of the landscape as open woodland. The study’s conclusion is that most discussion of Australia’s wildfire crisis stops at climate change, but the new evidence shows what actually set the stage for it: forest expansion and thickening that loaded the landscape with fuel long before the climate began to shift.

The findings carry significant weight for Gunaikurnai Traditional Owners, whose fire practice, known as towera, is understood within their culture as an interrelationship embedded in the practical daily life of the Old Peoples on Country. Uncle Russell Mullett, a Gunaikurnai elder from the Gunaikurnai Land and Waters Corporation, explained that Country not treated with towera becomes extremely dangerous for Gunaikurnai people, animals and plants alike. He welcomed the study as firm scientific evidence supporting towera land management initiatives, giving Traditional Owners a powerful empirical basis for reinstating practices that colonial displacement interrupted. The collaboration between the university researchers and the Gunaikurnai Land and Waters Corporation itself models the kind of partnership the paper argues is essential, combining Western palaeoecological methods with Indigenous ecological knowledge accumulated over millennia.

Beyond its immediate implications for fire policy, the study mounts a direct challenge to one of environmentalism’s most influential ideas: the concept of wilderness. Croajingolong National Park has long been treated as pristine wilderness, land largely untouched by human hands, and that framing has shaped how it is protected. Yet the sediment record shows the opposite. The forest now cherished as natural is, in Professor Fletcher’s words, a product of colonisation, and it is that legacy that now imperils the forest’s very survival. The park is today one of the most fire-prone and repeatedly burnt parts of southeastern Australia, a status the research attributes not to its natural condition but to the absence of the management that once sustained it. Protecting landscapes by excluding the people who shaped them, the study suggests, may be an ecological strategy that actively undermines the ecosystems it aims to preserve.

The technical strength of the work lies in its multi-proxy approach. By combining charcoal morphology to identify fire occurrence, infrared spectroscopy of charred material to reconstruct fire intensity, pollen analysis to track vegetation composition and sediment accumulation rates to quantify erosion, the researchers built a mutually reinforcing picture of cause and effect across a full millennium. The sequencing matters: because the rise in fire temperature precedes the eucalypt expansion in the record, the data support a causal chain in which hotter fires promoted denser forest, denser forest increased fuel loads, and increased fuel loads amplified subsequent fire behaviour. This feedback loop, once initiated by the cessation of cultural burning, converted a fire-resilient open woodland into a fire-vulnerable forest, and it did so before atmospheric greenhouse gas concentrations began their modern rise.

The paper concludes that restoring cultural burning and supporting Traditional Owners to care for Country is an essential component of mitigating wildfire risk, not a cultural gesture but a practical, evidence-based intervention. As southeastern Australian forests face intensifying fire weather under a warming climate, the research suggests that reducing the vulnerability of these landscapes requires addressing the colonial land-use legacies that made them combustible in the first place. The message from Croajingolong is stark and, for fire management agencies, potentially transformative: the current crisis is not solely a climate story, and the tools for rewriting it have been present on Country for thousands of years, waiting to be returned to use.

Subject of Research: Long-term palaeoecological reconstruction linking colonial cessation of Indigenous cultural burning to increased wildfire risk in southeastern Australian forests

Article Title: Australia's wildfire crisis linked to colonial land-use change

Article References: Australia's wildfire crisis linked to colonial land-use change. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: bushfires, cultural burning, Indigenous land management, Gunaikurnai, Croajingolong National Park, eucalypt forests, palaeoecology, lake sediments, colonisation, climate change, fire management, Nature

The scale of the global context makes the Australian gap especially concerning. Long-term monitoring in Germany recorded a 76 percent decline in flying insects over 27 years, while studies in Puerto Rico documented losses of 75 to 98 percent across 35 years. A recent global analysis suggests the number of bee species recorded has fallen by roughly a quarter since the 1990s, a figure that may partly reflect changes in reporting but could signal a genuine erosion of bee diversity. Australia, with few long-term insect datasets, cannot currently say whether similar declines are underway among its own bees. Only three native species hold formal federal threatened listings under the Environment Protection and Biodiversity Conservation Act, and the review argues the true number warranting protection is far higher.

The plight of already-listed species illustrates how precarious life can be for specialised bees in a modified landscape. Leioproctus douglasiellus survives in just three locations within the Perth metropolitan area, occupying a mere 0.2 square kilometres and visiting only two plant species, both of which are themselves listed as priority flora. Neopasiphae simplicior has been found at five sites, but recent surveys failed to detect it at two of them. Hesperocolletes douglasi was presumed extinct until a single specimen surfaced in 2015 in a woodland remnant of Western Australia’s Southwest Floristic Region; despite subsequent searching, no further individuals have been found. Perhaps most striking is Pharohylaeus lactiferus, rediscovered after more than a century without a record, which still lacks any formal conservation listing despite meeting the relevant criteria.

Fire has emerged as a particularly acute threat. Modelling of the catastrophic 2019 and 2020 bushfires found that nine native bee species qualified for listing as Vulnerable and two as Endangered based on habitat loss alone, while two-thirds of Australia’s bee species could not be assessed at all because there were insufficient collection records. The large carpenter bee Xylocopa aerata, which vanished from mainland South Australia and Victoria through a combination of land clearing and burning, now persists only on Kangaroo Island, around Sydney and along the Great Dividing Range. Conservationists had installed artificial nesting stalks on Kangaroo Island after 2007 fires, enabling nearly 300 females to reproduce, but the January 2020 blaze destroyed more than 150 of these nests and left only about 5 percent of the island’s habitat intact.

The review also weighs the contested role of the introduced European honeybee, which dominates many Australian bee assemblages. Evidence for competitive harm is mixed but mounting: hive introductions have reduced native bee flower visits, honeybee presence lowered the fecundity of the native bee Hylaeus alcyoneus, and competition can skew offspring sex ratios toward males. Recent work shows the impact depends on context, with negative associations strongest where floral resources are abundant, niche overlap high and habitats are residential gardens, and where vulnerable species are floral specialists or larger-bodied bees. Honeybees may also transfer pathogens to native species through shared flowers, a concern sharpened by the recent arrival of the Varroa destructor mite, whose establishment could cost Australian crop pollination between 0.63 and 1.31 billion dollars over three decades.

Urbanisation presents a genuinely two-sided picture. On the country’s east coast, results diverge: native bees in Melbourne preferred less urbanised sites, yet bee hotels in Sydney were occupied regardless of urbanisation intensity, and stingless bees in Queensland actually foraged more successfully in city environments. Western Australian studies tell a more consistent story of harm, with remnant bushland supporting richer, more specialised assemblages than residential gardens. Generalist species, including the honeybee and certain native Amegilla, Exoneura and Lasioglossum, dominate gardens, while specialist Euryglossinae, Leioproctus and Megachile cling to bushland remnants. Because over half of Australia’s bee species are pollen specialists, or oligolectic, relying on narrow lineages of native plants, introduced flora that displaces native vegetation can strip away the very resources these bees cannot substitute.

Pesticides add another layer of risk that is poorly quantified locally. Neonicotinoids, among the most widely used insecticides worldwide, impair learning, navigation and foraging in honeybees and bumblebees, reduce wild bee density and nesting, and cut reproductive output in solitary species. Yet nearly all risk assessments rest on the eusocial honeybee, whose biology differs radically from the solitary lifestyle that characterises most of the world’s 20,000 bee species, including the vast majority of Australia’s fauna. The review notes with concern that Australia continues to deploy neonicotinoids such as imidacloprid that other countries have restricted or banned over pollinator risks, while dedicated studies on native Australian bees remain scarce.

Not every anthropogenic influence is negative, and the review documents surprising winners. The wide-ranging Ceratina australensis is projected to expand under climate change. Leioproctus plumosus nests readily in suburban gardens, Hylaeus ruficeps kalamundae has adapted to nesting in human materials at densities never seen in nature, and the stingless bee Tetragonula carbonaria forages more successfully in urban environments than in macadamia plantations or natural vegetation. Freshly burnt landscapes can temporarily boost bee abundance and species richness by exposing the bare ground that most Australian bees, roughly 60 to 83 percent of species, need for nesting burrows. These gains, however, accrue mainly to generalists, and the authors caution that Australia’s long co-evolutionary history between plants and pollinators means Northern Hemisphere management prescriptions, such as soil nutrient enrichment, can backfire by favouring invasive weeds.

The economic and cultural stakes are substantial. Wild pollinators contribute an estimated 20 to 25 million Australian dollars annually to dryland lucerne seed production, and native species show genuine promise as managed crop pollinators: nine blue-banded bees, Amegilla chlorocyanea, in a caged trial of 100 plants outperformed a nucleus hive of 500 honeybee workers, and native species capable of buzz pollination, including Xylocopa, Amegilla and Lipotriches, are well suited to tomatoes and similar crops. Stingless bees already pollinate macadamias, blueberries, raspberries and lychees. Beyond agriculture, sugarbag bees have held deep significance for First Nations peoples for more than 65,000 years, with beeswax used in rock art for at least four millennia and honey and wax woven into diet, medicine, ceremony and toolmaking, knowledge that the review describes as amounting to a semi-domestication long before European arrival.

The authors’ roadmap is unambiguous. They call for urgent investment in taxonomy, with an estimated 300 to 500 species still undescribed and synonymisation rates revealing shaky foundations; for long-term monitoring using methods matched to species, since pan and vane traps miss many taxa while targeted netting captures both abundance and foraging data; for behavioural research on the learning, memory and decision-making that underpin bees’ capacity to adapt; and for expanded citizen science, building on initiatives such as the Wild Pollinator Count, which logged more than 20,000 insect observations in a single week in 2020. Distribution modelling can anticipate where threats will bite hardest before they become unmanageable. With Australia holding the worst mammal extinction record of any country over the past two centuries, the review warns that bees may be following a similar trajectory unseen, and that the window for building the knowledge base needed to prevent it is closing fast.

Subject of Research: Conservation of Australian native bees under environmental and anthropogenic change

Article Title: The Future of Native Bees in Australia Under Environmental and Anthropogenic Change

Article References: Howard, S. R., & Prendergast, K. S. (2026). The Future of Native Bees in Australia Under Environmental and Anthropogenic Change. Ecology and Evolution, 16(10), Article e74363. https://doi.org/10.1002/ece3.74363

Image Credits: AI Generated

DOI: 10.1002/ece3.74363

Keywords: native bees, Australia, pollinators, biodiversity, habitat loss, climate change, bushfires, European honeybee, pesticides, urbanisation, stingless bees, conservation