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Australia is home to a diverse assemblage of plant species that display marked population-level variation in inter-annual flower or seed output (i.e. masting). These include a semelparous bamboo with an estimated inter-crop period of 40–50 years, numerous iteroparous masting gymnosperms, angiosperms that include landscape-dominant eucalypts, arid-zone wattles and spinifex (Triodia spp.) grasses, and a rich selection of species that display disturbance-related forms of masting such as pyrogenic flowering and environmental prediction. Despite the prevalence of masting in the Australian flora, there has been a paucity of research on these plants. Nevertheless, from the literature available, it appears that, similar to other parts of the world, a continuum of inter-year reproductive variability exists, with a small number of species displaying extreme–high inter-annual seeding variability. From experimental studies and many anecdotal reports, most of the fitness benefits associated with masting evident overseas also operate in Australia (e.g. predator satiation, improved pollination efficiency, and environmental prediction). Additionally, some Australian masting species offer periodically important food resources for Aboriginal nations in the form of seed or fruit. These include the bunya pine (Araucaria bidwillii), members of the cycad genera Cycas and Macrozamia, spinifex (Triodia) grasses, and mulga shrubs (Acacia aneura). Key future research areas for effective conservation of Australian masting plants include (1) improved understanding of how management interventions such as burning and silvicultural thinning influence regeneration dynamics and higher-order trophic interactions, (2) further longitudinal monitoring across a range of habitats to identify other, as yet unknown, species that display reproductive intermittency, and (3) elucidation of how changes to temperature, precipitation and fire regimes under climate change will affect reproduction and regeneration dynamics of the Australian masting flora.

The explorer Ludwig Leichhardt travelled with Aboriginal people in south-east Queensland during 1843–44. Leichhardt’s record of Aboriginal taxonomy in Yagara, Wakka, Kabi, and other languages was related to the current taxonomy of the eucalypts of south-east Queensland. Most of the taxonomic entities could be associated across cultures and verifies the intimate understanding of Aboriginal peoples with tree species that are difficult to distinguish in the field. Leichhardt’s record together with that of Gairabau, a Dungidau man from south-east Queensland verifies a broad array of uses for eucalypts including as gum for chewing, dying, and medicine; ash rubbed into the skin for soothing young mothers, where bees, honey and wax can be found, hollow logs for fish-traps, hard timber for weapons and utensils, bark for shelter, canoes, embalming, and containers – some species contained water, others were used to create smoke for sending signals, some species indicated an unsuitable camp-site, and others indicated the likelihood of finding koalas and possum as game. Flowering and the shedding of bark are signs for the bush calendar.Warning: Aboriginal and Torres Strait Islander readers are advised that this article contains the names and images of deceased persons.

Artesian springs support important wetland ecosystems comprising highly specialised, endemic animal and plant species. Understanding the hydrogeological processes that sustain springs is critical to their management and characterisation of the connected groundwater system. This paper focuses on the springs of the Eulo and Bourke supergroups in the south-central part of the Great Artesian Basin in Queensland and New South Wales, Australia. These springs have been heavily impacted by aquifer drawdown, as a result of uncontrolled discharge of artesian water from pastoral bores. This study uses a stratigraphic model of the aquifer and aquitard sediments, a model of the potentiometric surface, existing information on the coverage of basement and surface structures, and a comprehensive field survey of all known springs to identify the association of springs with the edge of the geological basin, basement outcrop, basement highs, surface and deep basement faults, and a thinned aquitard. Many springs in the Eulo Supergroup are associated with basement highs and many springs are associated with deep faults, suggesting that reactivation of these faults may be an important cause of spring discharge. Springs in the Bourke Supergroup previously thought to be outcrop springs (gravity-fed), by virtue of their surface characteristics, are more likely to be artesian springs based on the interpretation of basement geology, surface faults and water chemistry, which align most closely to the Hooray Sandstone, the artesian aquifer underlying the springs.

Large‐scale land‐clearing has threatened Australian forest biodiversity, particularly within the South East Queensland bioregion where nearly 55 percent of humid‐climate eucalypt forest has been cleared. Restoration is key to the persistence of these forests but conventional reforestation techniques, including the exclusive use of locally sourced seed and nursery‐raised planting stock, are being reconsidered in terms of cost‐effectiveness and ability to create climatically resilient forests. In this study, we examined the success of a two‐year‐old direct seeding restoration project of Corymbia citriodora and Eucalyptus tereticornis from one local and two non‐local provenances. We established a field trial to compare germination rates of E. tereticornis seed and seed‐balls from the varying provenance sources in the field and in controlled laboratory growth chambers. We found no evidence of local provenance superiority in the field or in laboratory conditions. Periods of unseasonable rainfall and flooding may have constrained E. tereticornis germination in the field site. We conclude that direct seeding with seed‐balls may represent an effective method for establishing C. citriodora in South East Queensland, and that the approach warrants further investigation with other restoration species. Matching species with site conditions should be an initial consideration before long‐term revegetation investments are made.

Extinction is a profound biological event, yet despite its finality it can be difficult to verify and many frameworks have been proposed to define formally that extinction has occurred. For most taxonomic groups and regions there is no reliable list of species considered to be probably or possibly extinct. The record of plant extinctions in Australia is no exception, characterized by high turn-over within lists, low transparency of attribution and lack of consistency between jurisdictions. This makes it impossible to evaluate how many plant taxa have become extinct in Australia. We present an ecological framework for assessing the likelihood of plant extinctions, based on taxonomic soundness, degree of habitat modification, detectability and search effort, underpinned by the best available expert knowledge. We show that, in sharp contrast to both the fate of the Australian fauna and prevailing assumptions, only 12 of 71 plant taxa currently listed as or assumed to be extinct are considered probably extinct, and a further 21 possibly extinct. Twenty taxa listed as or assumed to be extinct have dubious taxonomy or occurrence in Australia, and the remaining 18 taxa are considered possibly extant and further surveys are required to ascertain their status. The list of probably and possibly extinct plants is dwarfed by the number thought extinct but rediscovered since 1980. Our method can be used for vascular floras in other regions characterized by well-documented and curated floras and high levels of expert knowledge, and provides a transparent platform for assessing changes in the status of biodiversity.

Palatable shrubs and trees in rangelands are vulnerable to grazing impacts, with local extinctions and declines documented. However, population trends are difficult to detect due to longevity of individuals and poor understanding of regeneration. We investigated the demography and conservation status of the Grey Range fuchsia (Eremophila stenophylla Chinnock), a geographically restricted and palatable shrub endemic to south-west Queensland. We documented 28 populations over 30,400 km, with an estimated total population size of 17,000 individuals. Seedling recruitment is rare and seedlings were observed at six populations, all with low or intermittent grazing pressure. In contrast, vegetative recruits were recorded at 19 populations and comprised at least 28% of plants measured. Resprouting confers some resilience to individuals, although repeated browsing restricts plant growth, limiting flowering and fruiting. Consistently heavily grazed populations also contain fewer plants. Although Eremophila stenophylla is secure in numerous populations with low grazing pressure, it qualifies as Vulnerable under IUCN Red List criteria due to past and ongoing decline at more than half of its populations. Grazing relief is necessary to ensure the long-term persistence of these populations. We predict that similar trajectories apply to other semi-arid shrubs, and research is required to inform grazing management to avert local extinctions.

Aim: Catastrophic forest mortality due to more extreme rainfall deficits and higher temperatures under future climate scenarios has been predicted. The aim of this study is to explore the magnitude of historical drought-induced tree mortality under pre-warming conditions. Location: North-eastern Australia. Time period: 1845–2017. Major taxa studied: Trees. Methods: Field survey, historical analysis and climate analysis. Results: We present evidence of 18%–30% tree mortality from recent droughts across three regions of north-eastern Australia with rainfall deficits less severe than earlier historical droughts. The corrected temperature record represents modest warming at the stations with long records in the vicinity of the study areas. In terms of rainfall deficit the most severe drought on record occurred in the early 20th century, and historical evidence confirms that this drought and earlier droughts before the advent of pastoralism coincided with substantial tree mortality. Main conclusions: Dramatic declines in woody biomass in response to drought historically occurred more than once a century and are a natural phenomenon in semi-arid Australia. The magnitude of drought-induced tree mortality under natural climate fluctuations requires further investigation in other continents. Widespread drought-induced tree mortality is not just a recent global change phenomenon and has been underestimated as a natural ecological process. However, even more severe forest die-off events from more extreme hotter droughts are predicted if Earth’s warming proceeds as currently projected.

QUESTIONS: The impact of invasive plant species on native diversity varies with spatial scale, with some invaders leading to broad‐scale diversity declines and others to only local declines. These discrepancies may reflect the invaders” capacity to reduce niche opportunities across spatial scales which can be associated with their functional traits. We investigated impact‐scale relationships and trait‐based mechanisms, in areas invaded by the exotic perennial grass species, Bothriochloa pertusa. We examine root traits specifically, as below‐ground competition was considered particularly important to the success of this species. LOCATION: Grassy “ironbark” woodlands of eastern Queensland, Australia. METHODS: We examined plots with varying degrees of invasion by B. pertusa, at multiple spatial scales (up to 1,000 m²) and analysed changes to the species–area relationships (SARs) with increasing invader cover. Changes to SARs were assessed in relation to the invaders” effect on rare (low patch occupancy) and common species in the community. In a separate analysis within the same habitat, we collected root cores across a gradient of invader cover and analysed changes to community root traits that were considered important correlates of competition for space and nutrients. RESULTS: Invasion‐induced reductions in diversity were pervasive at all scales investigated, and this was associated with a proportionally greater effect on rare species in the community. In the separate root analysis, changes in community root traits with increasing invader cover were potentially indicative of more intense competition for resources rather than space. CONCLUSIONS: The observed regional‐scale dominance of B. pertusa and associated declines in diversity warrant serious concern for the conservation of native plant communities and species in a region already at risk from other anthropogenic threats. Intense competition for below‐ground resources is likely a contributing mechanism to the success of B. pertusa in this study system. Experimental examination of this and other mechanisms would help to validate these findings.

Aims: Secondary forests are expanding rapidly in tropical regions and could play an important role in conserving native biodiversity and stabilising global climate. The recovery rate of plant communities in secondary forests varies considerably due to mechanisms associated with seed dispersal and recruitment dynamics. We explored these mechanisms along a chronosequence of tropical secondary forests in an agricultural landscape that was extensively cleared. Location: We explored these mechanisms along a chronosequence of secondary forests in tropical Australia. Methods: We used selected plant traits to characterise plant species and compared community composition between demographic stages (i.e. soil seedbank, understorey and overstorey) and forest age categories. We collected soil samples to assess seedbank composition and used quadrants and transects to assess understorey and overstorey plant community composition at each site. Results: For all demographic stages, we found that young (4-12 years) and intermediate-aged forests (16-20 years) were dominated by early successional, small-seeded species and traits associated with disturbed forests. In old secondary forest (23-34 years) some traits associated with late successional stages were present (e.g. large seeds, trees). However, the traits and species composition of mature forests remained distinct from all secondary forests. Across the chronosequence, forest age and demographic stage were significant factors in discriminating species and trait composition between forest sites. We found clear plant community similarities within demographic stages, despite the forest age differences. This suggests stronger limitations to dispersal and recruitment between demographic stages than between forest ages. Conclusions: Our results show that secondary forests in this region assemble slowly with dispersal and recruitment limitations constraining their recovery. Although a successional transition in species and plant traits composition along the chronosequence is clear, similarities to mature forests remain low. The slow recovery of late successional and large-seeded species in these secondary forests suggests that active restoration of such species may be necessary if we want to enhance the capacity of these forests to conserve native biodiversity.

Questions: Buffel grass (Cenchrus ciliaris L.) is a drought-adapted invasive plant that has become a serious environmental weed in many arid and semi-arid systems. This paper examined whether eradication of buffel grass infestations: (i) increases frequency, richness and diversity of native vegetation and seed bank pools; and (ii) improves availability of seed resources for granivores. Location: Alluvial ironwood/corkwood woodlands in arid central Australia. Methods: We assessed differences in floristic and seed bank composition between buffel-infested sites and sites where buffel grass had been eradicated ca. 12 years previously. Plant species frequency data from nested-quadrat sampling were amalgamated into plant functional groups to examine their relationship to buffel treatment. A seed flotation method was employed to: (i) assess seed bank composition of functional groups at eradicated vs. infested sites; and (ii) test whether the mass of seeds available for granivores was higher at buffel-free sites. Results: Buffel-eradicated sites supported richer and more diverse vegetation and seed banks across all functional groups except perennial grasses. The effect was strongest for perennial forbs, annual/short-lived forbs, and annual/short-lived grasses. The overall mass of seeds of non-buffel grass species was ca. 10-fold higher at buffel-removed sites. Numbers of seeds of species in the 0.001–0.009 9 g and 0.000 1–0.000 99 g size classes, both of which contain species with seeds consumed by granivores, were ca. 20- and 14-fold higher respectively at buffel-removed sites. Conclusions: Buffel grass removal at localised scales provides islands of habitat with improved opportunities for native plant re-establishment and abundant foraging resources for granivores. Future research must disentangle the relative importance of dispersal vs. residual seed banks for community restoration after buffel grass invasion. Extended delays in eradication could allow seed bank reserves to deteriorate to a state that no longer permits regeneration.

Myrtle rust is a fungal disease that has spread rapidly across the globe, arriving in Australia in 2010. The tree species Rhodomyrtus psidioides is nearly extinct in the wild as a result of the disease, leading to potential disruption of ecosystem function. Many other Myrtaceae may also be threatened and unprecedented impacts of the disease are predicted.

Land-use change, and associated land clearing/conversion and fragmentation are major drivers of biodiversity decline across the globe. The spread of invasive species is a well-recognised consequence of land-use change. The extent and intensity of invasion however is often difficult to assess due to a lack of temporal data. Using detailed mapping information for 130, 950 km2 of sub-coastal Queensland, Australia and results from field surveys we investigated changes to land-use, the extent of remnant (intact) vegetation and the spread of prominent invasive plant species over time (1997-2018). In the 50 years prior to 1997 the area underwent significant land development (mostly for livestock grazing and crops), resulting in a reduction of 45% of its remnant vegetation. Despite key policy developments aimed at protecting the remaining vegetation and species, 7392 km2 was cleared/converted between 1997 and 2017, mainly for the expansion of grazing and cropping lands. Vegetation types specifically listed for national protection under these policies were some of the greatest affected, highlighting the need for improved implementation and regulation of these control measures. Within remaining fragments of remnant vegetation, the cover and presence of two invasive perennial grass species indian couch (Bothriochloa pertusa) and buffel grass (Cenchrus ciliaris) increased significantly during this time period. There was also a moderate increase in the cover and presence of the annual herb Parthenium weed (Parthenium hysterophorus). The spread of these species within the landscape likely reflects an 'invasion debt', incurred from an intense history of land-use within the region and we predict this trend will continue to threaten remnant ecosystems.

Aim: Spring wetlands in arid regions of Australia provide habitat for many highly endemic organisms, including fish, molluscs, crustaceans and plants, but these unique ecosystems have been under pressure since the arrival of Europeans about 250 years ago. Arguments over whether particular plant species are long-term spring inhabitants or recent immigrants are confounding efforts to conserve spring flora. One such example is the swamp foxtail, Cenchrus purpurascens, a grass that is variably listed in the literature as being native to Australian wetlands or as being an introduced weedy species from Asia.Location: Australia, China and Korea.Methods: We use DNA sequences of the nuclear ITS and the chloroplast DNA regions trnL-F and matK, complemented with newly designed simple sequence repeat (SSR) markers, to assess the native status of C. purpurascens in Australia and determine whether there is genetic differentiation among spring populations.Results: We find that, although there has been gene flow between Asia and Australia in the geological past, the populations are now strongly differentiated: C. purpurascens has probably been present in Australia through the Pleistocene. In Australia, there is also strong genetic differentiation among populations from different springs, and between springs and non-springs populations, indicating long-term occupancy of some springs sites.Main conclusions: Cenchrus purpurascens was present in Australia well before European colonization of the continent. The level of genetic differentiation among populations enhances the existing conservation values of Elizabeth Springs, Edgbaston, Doongmabulla and Carnarvon Gorge springs complexes within the Great Artesian Basin.

Aim: Springs in the Australian arid zone are distinct from other waterways because they house a large number of endemic species. We aimed to assess spatial patterns in endemic diversity at a basin-wide scale and whether environmental features can help to explain them. In doing so, we take the opportunity to summarize the current state of conservation in the system.Location: Great Artesian Basin (GAB), arid and semiarid regions of eastern AustraliaMethods: We combine data regarding the location of springs with published GIS layers regarding environmental characteristics and a literature review of all species and subspecies documented in the published literature to be endemic to GAB springs.Results: We found evidence of 96 species and subspecies of fishes, molluscs, crustaceans and plants endemic to these springs. The majority of endemic species are invertebrates with geographical distributions limited to a single spring complex (

Where habitat loss is rapid, formerly common species may be at risk of extinction. We provide a method for using habitat mapping data and herbarium records to identify plant species that are threatened by the rapid conversion of brigalow forest, a widespread habitat type in eastern Australia that has been decimated over the last 60 years. The method weights species depending on the strength of their association with the brigalow forest habitat and their association with the Brigalow Belt region where the clearance of native vegetation has been extensive. The process identifies 56 out of a total of 1229 plant species that are at greatest potential risk. Twenty of the 56 species also occur in habitats that have not been extensively cleared. Of the remaining 36 species, 11 are closely associated with brigalow forest, which in general has been more extensively cleared than other habitats. The method revealed several species potentially imperilled by habitat loss that have not previously been identified by formal listing of threatened species. The rate of habitat loss for the target species can be clearly documented, although further survey is required to determine the potential persistence of species in habitat that has been modified by clearing and an estimate of generation length of the plant species is required in order to assess this decline against IUCN threat categories. The method has broad application in situations where there are records of species and documentation of habitat loss.

Plant species with fire-triggered germination are common in many fire-prone ecosystems. For such plants, fire timing in relation to the timing of reproduction may strongly influence post-fire population regeneration if: (a) flowering occurs infrequently (e.g. plants are mast seeders); and (b) seed survival rates are low and input from the current year's flowering therefore contributes a large proportion of the viable dormant seedbank. The role of fire timing in relation to masting as a driver of post-fire recruitment has rarely been examined directly, so this study tested the hypothesis that fires shortly after masting trigger increased recruitment of the obligate-seeding arid zone spinifex, Triodia pungens R. Br., an iteroparous masting grass with smoke-cued germination. Phenological monitoring of T. pungens was conducted over 5 years, while a longitudinal seedbank study assessed the influence of seeding events on soil-stored seedbank dynamics. Concurrently, a fire experiment with randomized blocking was undertaken to test whether T. pungens hummocks burnt shortly after masting have greater post-fire recruitment than hummocks burnt when there has not been recent input of seeds. Triodia pungens flowered in all years, though most flowerings were characterized by high rates of flower abortion. A mast flowering with high seed set in 2012 triggered approx. 200-fold increases in seedbank densities, and seedbank densities remained elevated for 24 months after this event. The fire experiment showed significantly higher recruitment around hummocks burnt 6 months after the 2012 mast event than around hummocks that were burnt but prevented from masting by having inflorescences clipped. Fires shortly after masting trigger mass recruitment in T. pungens because such fires synchronize an appropriate germination cue (smoke) with periods when seedbank densities are elevated. Interactions between natural fire regimes, seedbank dynamics and fire management prescriptions must be considered carefully when managing fire-sensitive masting plants such as T. pungens.

Myrtle rust is caused by the fungus Austropuccinia psidii and impacts some species in the extremely large and mostly Gondwanic plant family, the Myrtaceae. Given the location of its wild relatives, the fungal pathogen originated in South America and spread rapidly across the Pacific. Here we report on extensive surveys from Australian rainforest to predict a plant extinction event of unprecedented magnitude. The results predict the imminent extinction of 16 rainforest tree species in the wild due to myrtle rust within a generation. A further 20 species may be at risk, but further monitoring is required to determine their fate. Myrtle rust retards growth and precludes reproduction on these severely affected species. To avoid total extinction, strategies for in-situ and ex-situ rescue are presented.

Patterns of distribution are influenced by species environmental requirements and limits, but experimental tests are needed to discern whether correlates of abundance directly affect survival and success. Springs in Australia’s arid interior support a wide diversity of gastropods only found in springs, and these species show dichotomous patterns of distribution. “Amphibious” species are broadly distributed across many springs and microhabitats, and “aquatic” species confined to the deepest pool areas within large springs. This pattern appears to be driven by the interaction between different environmental conditions in different microhabitats and the environmental tolerances of each endemic snail species. Factorial experiments were used to test whether conditions in the environmentally extreme and variable tail area of springs (considering pH, conductivity, temperature and desiccation potential, alone and in synergistic scenarios) elicited lethal or sub-lethal responses in spring snails endemic to springs on opposite sides of the Australian arid zone. All species restricted to spring pools were able to endure 24 h exposed to the average tail conditions, alone and in combination, but most suffered mortalities when subjected to extremes, and mortalities occurred sooner in the most restricted species when elevated pH and conductivity were experienced in combination. Responses of species from different locations are similar, but pattern of distribution in the field were not correlated with tolerance of environmental extremes—with the “amphibious” species from the sub-tropics being far more sensitive than its arid counterpart. These findings suggest that environmental variance within springs can influence patterns of distribution and abundance, particularly when extremes are experienced simultaneously over sustained time periods. But despite similarities in responses across species from these two spring complexes, no simple generalisations linking distribution and tolerance were discernible.

Rainfall, fire and competition are emphasized as determinants of the density and basal area of woody vegetation in savanna. The semi-arid savannas of Australia have substantial multi-year rainfall deficits and insufficient grass fuel to carry annual fire in contrast to the mesic savannas in more northern regions. This study investigates the influence of rainfall deficit and excess, fire and woody competition on the population dynamics of a dominant tree in a semi-arid savanna. All individuals of Eucalyptus melanophloia were mapped and monitored in three, 1-ha plots over an 8.5 year period encompassing wet and dry periods. The plots were unburnt, burnt once and burnt twice. A competition index incorporating the size and distance of neighbours to target individuals was determined. Supplementary studies examined seedling recruitment and the transition of juvenile trees into the sapling layer. Mortality of burnt seedlings was related to lignotuber area but the majority of seedlings are fire resistant within 12 months of germination. Most of the juveniles (≤1 cm dbh) of E. melanophloia either died in the dry period or persisted as juveniles throughout 8.5 years of monitoring. Mortality of juveniles was positively related to woody competition and was higher in the dry period than the wet period. The transition of juveniles to a larger size class occurred at extremely low rates, and a subsidiary study along a clearing boundary suggests release from woody competition allows transition into the sapling layer. From three fires the highest proportion of saplings (1-10 cm dbh) reduced to juveniles was only 5.6% suggesting rates of 'top-kill' of E. melanophloia as a result of fire are relatively low. Girth growth was enhanced in wet years, particularly for larger trees (>10 cm dbh), but all trees regardless of size or woody competition levels are vulnerable to drought-induced mortality. Overall the results suggest that variations in rainfall, especially drought-induced mortality, have a much stronger influence on the tree demographics of E. melanophloia in a semi-arid savanna of north-eastern Australia than fire.

In many of the world's arid regions there has been a dramatic increase in grazing pressure with herds of livestock sustained by the provision of artificial water points. In these systems it has been suggested that grazing-sensitive plant species will have contracted to refuges distant from water points where grazing impacts are low. This association was tested using a large data set of presence/absence records for rare plant species throughout the northeastern Australian arid zone. The presence records of only one of 45 species were statistically associated with lower grazing activity, as a function of distance-to-water, than the absence records. The field observation that this species is rarely grazed suggests it is not susceptible to grazing pressure. In general, the study supports assertions that populations of short-lived plants in drylands are resilient in the face of exaggerated livestock grazing because herbivores are not in sufficient densities to have an impact during the sporadic periods of high rainfall when plants can complete their life cycles. However, long-lived palatable species may be extinction-prone in grazed landscapes over long time frames if recruitment is curtailed by grazing.

Alternative vegetation types that switch from one to another under contrasting fire regimes are termed fire-mediated alternative stable states (FMASS). Typically, pyrophylic communities (i.e., vegetation assemblages favored by burning) dominate under high frequencies or intensities of fire. Conversely, fire-sensitive (pyrophobic) vegetation types persist under long fire-free conditions. As the persistence traits of plants of FMASS systems are generally poorly researched, threshold levels of pyric disturbance that trigger ‘state-switching’ are often unknown. Dense thickets of the obligate-seeder shrub waputi (Aluta maisonneuvei ssp. maisonneuvei [Myrtaceae]) form fire-retarding woody islands within highly flammable spinifex (Triodia spp.) grasslands in arid Australia. To examine the tolerance of Aluta thickets to burning, we investigated: (1) the influence of post-fire rainfall and fire severity on recruitment (a field study); (2) soil seedbank densities (a field study); and (3) fire-related dormancy cues in seeds (a germination trial). We found a positive relationship between recruitment and post-fire rainfall volume, and much higher mean recruitment at sites with high- (5.9 seedlings/m2) than low-severity-burnt (2.2 seedlings/m2) and unburnt shrubs (0.03 seedlings/m2). Post-fire regeneration was mediated by dense soil-borne seedbanks, and the germination trial indicated that smoke promoted germination. Although Aluta shrubs are invariably fire-killed, high-severity fires are unlikely to lead to state shifts from shrubland to grassland because of the ability of mature stands to regenerate from dense, fire-cued seedbanks. Nevertheless, given that Aluta seedlings are exceptionally slow-growing, post-fire droughts combined with fire-return intervals less than the Aluta primary juvenile period of c. 5 years could drive conversion from Aluta- to Triodia-dominated vegetation.

The artesian springs of inland Australia are a unique habitat in what is otherwise an arid environment. They support a rich collection of endemic flora and fauna. Here, morphological and molecular data are employed to describe a new species, Chloris circumfontinalis Fahey & Fensham, endemic to artesian spring systems in central Queensland. A morphological ordination failed to distinguish this species from other Australian native flora, but the shape of the florets distinguishes it from the species with which it co-occurs. Phylogenies estimated from molecular data showed that the species represents a distinct lineage that may be sister to species of Chloris from outside Australia. Chloris circumfontinalis occurs only in the saline scalds that form around the springs, and population surveys at the two sites where it occurs indicated a threat status of Endangered under the IUCN Red List criteria.

At fine spatial scales, savanna-rainforest-grassland boundary dynamics are thought to be mediated by the interplay between fire, vegetation and soil feedbacks. These processes were investigated by quantifying tree species composition, the light environment, quantities and flammability of fuels, bark thickness, and soil conditions across stable and dynamic rainforest boundaries that adjoin grassland and eucalypt savanna in the highlands of the Bunya Mountains, southeast Queensland, Australia. The size class distribution of savanna and rainforest stems was indicative of the encroachment of rainforest species into savanna and grassland. Increasing dominance of rainforest trees corresponds to an increase in woody canopy cover, the dominance of litter fuels (woody debris and leaf), and decline in grass occurrence. There is marked difference in litter and grass fuel flammability and this result is largely an influence of strongly dissimilar fuel bulk densities. Relative bark thickness, a measure of stem fire resistance, was found to be generally greater in savanna species when compared to that of rainforest species, with notable exceptions being the conifers Araucaria bidwillii and Araucaria cunninghamii. A transect study of soil nutrients across one dynamic rainforest – grassland boundary indicated the mass of carbon and nitrogen, but not phosphorus, increased across the successional gradient. Soil carbon turnover time is shortest in stable rainforest, intermediate in dynamic rainforest and longest in grassland highlighting nutrient cycling differentiation. We conclude that the general absence of fire in the Bunya Mountains, due to a divergence from traditional Aboriginal burning practices, has allowed for the encroachment of fire-sensitive rainforest species into the flammable biomes of this landscape. Rainforest invasion is likely to have reduced fire risk via changes to fuel composition and microclimatic conditions, and this feedback will be reinforced by altered nutrient cycling. The mechanics of the feedbacks here identified are discussed in terms of landscape change theory.

Plant succession theory underpins the development of strategies for the conservation and regeneration of native communities. Current theory has been based largely on space-for-time rather than long-term monitoring data, which have known limitations. There is general consensus that more site-specific studies are needed to corroborate existing hypotheses. The target vegetation is a brigalow (Acacia harpophylla, Mimosaceae) forest in one of Australia's most endangered ecosystems, which was cleared and burnt in 1963. Forty quadrats were placed systematically within each of six 20 m × 20 m permanent plots. Presence, density and per cent canopy cover data were recorded for each species at 18 times over 46 years. Brigalow dominated the original vegetation, assumed dominance soon after clearing through massive root suckering and remained dominant throughout the study. It achieved maximum density within two years when severe intraspecific competition led to self-thinning. After approximately 30 years, vacant niches appeared. Woody understorey species were slow to recolonise. Species richness and other diversity indices increased rapidly to a maximum after 2–4 years, declined until the 30th year when they again increased. This was the pattern of the species-rich herbaceous layer; woody species showed a steady monotonic increase. The ‘hump-shaped’ relationship between cover (biomass) and species richness was confirmed. This example fits the inhibition model for which few examples have been described. While the long-term successional pattern is slightly confounded by climatic variability preceding sample surveys, this space-for-time study not only supports a bimodal pattern of diversity over time but also indicates that the relative species richness of the herbaceous and woody layers may explain the extreme variability reported in the literature.

Questions: Which factors affect the diversity and species composition of tropical secondary rain forests in a region with little information regarding their contribution to global biodiversity? Can older secondary forests approach the diversity and composition of mature forests following 100 yr of pasture use? Location: Tropical secondary rain forest, northeast Australia. Methods: We identified trees, shrubs and vines ≥2.5 cm DBH in a chronosequence comprising 33 sites, aged 3–60 yr since the formation of closed canopy (9–69 yr since pasture abandonment) and compared them with eight sites in nearby mature forest remnants. Results: Species richness and community composition were strongly influenced by secondary forest age but did not attain values of mature forest. Sites in close proximity to mature forests had higher plant richness, whereas low soil fertility appeared to depress species recruitment. Thus, multiple factors operated in secondary forest community assembly. Unusual tree community patterns that suggest accelerated or slowed successional trajectories were observed at several sites. Conclusions: Secondary forests in our study region contained important plant diversity for conservation, particularly in older sites, however, even the oldest secondary forests (60 yr) did not converge with the species composition and diversity of mature forests. The protection of mature forest tracts and remnants must be a priority if we are to maintain high levels of plant diversity in tropical landscapes, conserve rare species and facilitate the recruitment of plant species in recovering forests.

The distribution of surface water dictates human and animal activity in arid zones. Although typically small, hidden, and inaccessible, springs and wells fed by local aquifers were the only sources of reliable water across vast areas of inland Australia until the last century. Compared to larger, more accessible water sources such as riverine waterholes and Great Artesian Basin discharge springs, their history is sketchy and poorly documented, although rich in intrigue and mythology. Since the expansion of artificial waters and motorised transport, many of these small oases have become forgotten, and their location and permanence are now less well-known than for thousands of years. We examine the distribution, hydrogeology, cultural history, and biological values of Tertiary sandstone springs in western Queensland based on a review of historical literature, interviews with long-term residents, and extensive field surveys. One hundred and sixty springs were documented, and nearly 40% of these have declined in flow or become inactive since pastoral settlement for reasons that are not well understood. While their decline in some areas seems related to shallow bores sunk into their local aquifers, it is possible that some smaller springs owed their existence to regular human maintenance. Others are probably naturally dynamic over decadal time scales. This study documents an almost-forgotten aspect of Queensland's natural and cultural history.

(1) The distribution of organisms that inhabit patchy systems is dictated by their ability to move between patches, and the suitability of environmental conditions at patches to which they disperse. Understanding whether the species involved are identical to one another in their environmental requirements and their responses to variance in their environment is essential to understanding ecological processes in these systems, and to the management of species whose patchy and limited distributions present conservation risks. (2) Artesian springs in Australia&rsquo, s arid interior are &ldquo, islands&rdquo, of hospitable wetland in uninhabitable &ldquo, oceans&rdquo, of dry land and are home to diverse and threatened assemblages of endemic species with severely restricted distributions. Many have strict environmental requirements, but the role of environmental heterogeneity amongst springs has rarely been considered alongside conventional patch characteristics (isolation and patch geometry). (3) We quantified environmental heterogeneity across springs, and the relationship between spring size, isolation (distances to neighbours) and environmental quality (depth, water chemistry), and patterns of occupancy and population persistence of six endemic spring snail species, all from different families, and with all restricted to a single &lt, 8000 ha system of springs in Australia. To do so, a survey was conducted for comparison against survey results of almost a decade before, and environmental variables of the springs were measured. Many of the snail species occupied few sites, and environmental variables strongly covaried, so an ordination-based approach was adopted to assess the relationship between environmental measures and the distribution of each species, and also whether springs that held a higher diversity of snails had specific characteristics. (4) Each snail species occupied a subset of springs (between 5% and 36% of the 85 sampled) and was associated with a particular set of conditions. Of the six species considered in further detail, most were restricted to the few springs that were large and deep. Species in family Tateidae were distinct in having colonised highly isolated springs (with &gt, 300 m to nearest neighbour). Springs with highest diversity were significantly larger, deeper and had more numerous neighbours within 300 m than those devoid of endemic snails, or those with low diversity. (5) Although spring size and isolation affect patterns of occupancy, the six snail species had significantly different environmental requirements from one another and these correlated with the distribution pattern of each. Approaches that ignore the role of environmental quality&mdash, and particularly depth in springs&mdash, are overlooking important processes outside of patch geometry that influence diversity. These organisms are highly susceptible to extinction, as most occupy less than 3 ha of habitat spread across few springs, and habitat degradation continues to compromise what little wetland area is needed for their persistence.

Surface water availability in drylands has changed with the introduction of artificial water points. Despite known ecological impacts, detailed mapping of this change has not occurred in most drylands. We aimed to quantify the extent and distribution of changes in water availability. We tested whether water availability increased more in pastorally productive areas than less fertile areas, and whether remaining water remote areas are restricted to low productivity landscapes. Our new spatially-explicit method mapped access to water at fine spatial scale, weighting locations by their distance to water and the permanence of those water sources. We demonstrated our method in a study area of over 700,000 km2 in Queensland, Australia, with our mapping showing large changes in water availability since pastoral development. Less than 5% of the study area is now more than 10 km from water, compared with almost 60% previously. Few refuges for grazing-vulnerable communities remain. Even low fertility landscapes showed marked increases in water availability. This has conservation implications for managing production landscapes. Our approach can be applied in any dryland landscapes that have experienced changes in water availability, and can help guide actions such as removing artificial water points to recreate ecological refuges.

The 822 eucalypt species (Angophora, Corymbia, Eucalyptus) within Australia were assessed using IUCN Red List Categories and Criteria. Overall, 193 (23%) eucalypts qualified as threatened and 36 were considered Data Deficient. One hundred and thirty-four threatened species qualified under criterion A2, representing a past and irreversible population decline of >30%. The remainder were narrow-range species with ongoing threats (mostly mining or urbanisation), or naturally rare. Habitat conversion to crops and pastures was the cause of decline for most threatened eucalypts. Threatened species were concentrated where deforestation and high eucalypt richness coincide, especially south-western Western Australia. Corymbia or Angophora species, and relatively few tropical eucalypts are threatened. Fire, timber harvesting and disease were rarely sufficient threats to eucalypts to warrant a threatened status. Sheep grazing limits regeneration in temperate woodlands, but requires further quantification for individual species. Prior to this study, 89 eucalypts were listed as threatened under Australian environmental law. This assessment recommends that 32 of these species be downgraded to Near Threatened or Least Concern. A further 11 species were identified as Data Deficient, while an additional 147 species were proposed for listing as threatened. This systematic assessment of Australian eucalypts emphasises the importance of decline rather than rarity when compared with previous listings, with broad implications for listing long-lived plants in deforested landscapes.

Eucalyptus argophloia is a species with a small geographic range occurring in a productive landscape with a subhumid climate. The past distribution of the species was assessed from remnant vegetation and standing paddock trees. The species grows in three specific vegetation types within its geographic range, and based on densities in remnant vegetation and reduction of habitat, it is estimated that the population has been reduced by 94.2%. There is very little regeneration of the species including on ungrazed roadsides, and further decline of the species is expected. The species can be categorised under IUCN Red Listing criteria as Critically Endangered. The present study provides a method for using habitat association, population decline and stand structure for conservation assessment of threatened tree species in productive landscapes.

Strawberry guava (Psidium cattleianum) is a shade-tolerant shrub or small tree invader in tropical and subtropical regions and is considered among the world's top 100 worst invasive species. Studies from affected regions report deleterious effects of strawberry guava invasion on native vegetation. Here we examine the life history demographics and environmental determinants of strawberry guava invasions to inform effective weed management in affected rainforest regions. We surveyed the vegetation of 8 mature rainforest and 33 successional sites at various stages of regeneration in the Australian Wet Tropics and found that strawberry guava invasion was largely restricted to successional forests. Strawberry guava exhibited high stem and seedling densities, represented approximately 8% of all individual stems recorded and 20% of all seedlings recorded. The species also had the highest basal area among all the non-native woody species measured. We compared environmental and community level effects between strawberry guava-invaded and non-invaded sites, and modelled how the species basal area and recruitment patterns respond to these effects. Invaded sites differed from non-invaded sites in several environmental features such as aspect, distance from intact forest blocks, as well as supported higher grass and herb stem densities. Our analysis showed that invasion is currently ongoing in secondary forests, and also that strawberry guava is able to establish and persist under closed canopies. If left unchecked, strawberry guava invasion will have deleterious consequences for native regenerating forest in the Australian Wet Tropics.

Invasive species pose a substantial risk to native biodiversity. As distributions of invasive species shift in response to changes in climate so will management priorities and investment. To develop cost-effective invasive species management strategies into the future it is necessary to understand how species distributions are likely to change over time and space. For most species however, few data are available on their current distributions, let alone projected future distributions. We demonstrate the benefits of Bayesian Networks (BNs) for projecting distributions of invasive species under various climate futures, when empirical data are lacking. Using the introduced pasture species, buffel grass (Cenchrus ciliaris) in Australia as an example, we employ a framework by which expert knowledge and available empirical data are used to build a BN. The framework models the susceptibility and suitability of the Australian continent to buffel grass colonization using three invasion requirements; the introduction of plant propagules to a site, the establishment of new plants at a site, and the persistence of established, reproducing populations. Our results highlight the potential for buffel grass management to become increasingly important in the southern part of the continent, whereas in the north conditions are projected to become less suitable. With respect to biodiversity impacts, our modelling suggests that the risk of buffel grass invasion within Australia’s National Reserve System is likely to increase with climate change as a result of the high number of reserves located in the central and southern portion of the continent. In situations where data are limited, we find BNs to be a flexible and inexpensive tool for incorporating existing process-understanding alongside bioclimatic and edaphic variables for projecting future distributions of species invasions.

Predicting the consequences of climate change on forest systems is difficult because trees may display species-specific responses to exaggerated droughts that may not be reflected by the climatic envelope of their geographic range. Furthermore, few studies have examined the postdrought recovery potential of drought-susceptible tree species. This study develops a robust ranking of the drought susceptibility of 21 tree species based on their mortality after two droughts (1990s and 2000s) in the savanna of north-eastern Australia. Drought-induced mortality was positively related to species dominance, negatively related to the ratio of postdrought seedlings to adults and had no relationship to the magnitude of extreme drought within the species current geographic ranges. These results suggest that predicting the consequences of exaggerated drought on species' geographic ranges is difficult, but that dominant species like Eucalyptus with relatively slow rates of population recovery and dispersal are the most susceptible. The implications for savanna ecosystems are lower tree densities and basal area.

Aim: To investigate the role of clay in limiting the development of woody biomass in drylands. Location: Australia. Methods: Spatial data representing woody biomass, soil clay content and climate for the Australian continent were interpreted to explore the relationship between a moisture index and woody biomass on clay and non-clay substrates. Moisture and soil water potential were investigated through time for clay and sand plains. Sub-soil clay and other soil characteristics were compared between areas with and without high tree mortality after drought. Results: The substantially lower woody biomass on clay soils than non-clay soils in the drylands of the Australian continent verifies the inverse texture effect. A clay floodplain consistently held more water than an adjacent sandplain, but soil moisture in the clay was effectively inaccessible to plants for much longer periods because of more negative values of water potential in the clay soil. Small increases in sub-soil clay were associated with high tree mortality. Main conclusions: Our findings suggest that the 'inverse texture effect', which describes the negative association of woody biomass with soil clay content in drylands, may mostly relate to the moisture-retentive properties of clay rather than being caused by reduced infiltration and enhanced evaporation from clay-rich soils. Our evidence suggests that clay soils constrain woodiness in drylands by exacerbating water stress, and confirm the fundamental role of aridity in determining woody biomass and the global distribution of grassland.

Fauna assemblages were assessed within four primary vegetation types and three edge types between grassland and wooded habitats within the Bunya Mountains of eastern Australia. Wet rainforests differed in their species assemblages to dry rainforest, savanna woodland and grassy bald. Dry rainforests and savanna woodlands had similar species composition despite their dissimilar floristic and structural attributes. The small grassy balds supported lower vertebrate species richness and abundance and were significantly different in species composition to all other vegetation types. The small and structurally simple grassy balds contained a subset of species also found in surrounding forest and woodland vegetation, with only a few grassland specific species. Fauna assemblages in grassy bald-rainforest edges were significantly different to grassy balds and rainforest interiors, while grassy bald-savanna woodland edges were similar to savanna woodland interiors. The reptile Lampropholis colossus, the only endemic...

Aim We examined patterns of rarity in the flora of a semi-arid mountain range with a high concentration of rare species and 150 years of elevated grazing pressure, to establish the influences of habitat specialization, species biology, biogeography and grazing pressure in determining the distributions and abundances of species. Location Grey Range and associated Tertiary sandstone ranges, eastern semi-arid Australia. Methods We characterized the major habitats by soil and vegetation parameters, and surveyed 647 sites across seven habitat units to determine the probability of occurrence of 19 rare species. We then analysed the occurrence of rare plants in relation to species biology (dispersal characteristics, flowering, fruiting and recruitment frequency), grazing pressure and, for the barren plateaux, their size and isolation. Results Rare species were found to be concentrated in three restricted habitat types – barren plateaux, gidgee toeslopes and sheltered habitats – which are clearly separated from other habitats in land-form, soil properties and floristics. Larger barren plateaux were more likely to harbour rare species, but there was no correlation between plateau isolation and the incidence of rare plants. No species seemed to be limited by low seed production, but barren-plateau shrubs recruited only infrequently. Only two species were adapted to long-distance dispersal, meaning that most are effectively stranded in their insular habitats. Although five perennial shrub species were heavily grazed, there were no significant relationships between the distance to water and the occurrence of rare plants. Main conclusions Habitat specialization, reproductive biology and biogeographical history interact to create the observed patterns of rarity in this semi-arid mountain range. There is no evidence that any species have become rare or restricted as a result of grazing pressure. Species confined to plateaux, sheltered habitats and gidgee toeslopes represent relictual populations, and the association of rare plants with larger plateaux suggests that local extinctions were more likely on smaller plateaux during Pleistocene climatic fluctuations.

Aim: To assess hypotheses about the role of anthropogenic fire in the maintenance and origin of a fine-scale vegetation mosaic of rain forest, eucalypt savanna and grassland. Location: Bunya Mountains, subtropical eastern Australia. Methods: A time series of vegetation maps was compiled from historical and recent aerial photography and field surveys. Geospatial models were constructed of environmental domains for rain forest, savanna and grassland, and for areas of biome change. Grassland soils were analysed for carbon isotope ratios (δ13C), and radiocarbon (14C) dates were acquired for bulk samples from a range of depths. Results: Analysis revealed weak associations between topography and the distribution of rain forest, savanna and grassland, and their patterns of recent change. Grassland occupied an environmental domain intermediate between rain forest and savanna and was more than four times as likely to occur within a matrix of rain forest rather than savanna. There was a large proportional reduction in the area of both grassland (-35%) and savanna (-19%) between 1961 and 2006 because of the expansion of rain forest. However, the greater initial extent of savanna meant that the areal loss of savanna was an order of magnitude greater than for grassland (1433 vs. 146 ha). There was no evidence of abrupt changes in δ13C in grassland soil profiles, indicating stability of the vegetation over the last 2000 years. Main conclusions: There is no simple gradient in 'tree suitability' from rain forest, through savanna, to treeless grassland on the Bunya Mountains. A general absence of fire since the 19th century has greatly reduced the extent of grassy savanna and grassland formations, to the advantage of rain forest. These results support the hypothesis that the vegetation mosaic on the Bunya Mountains is a cultural artefact and testament to millennia of skilful and persistent burning. We could not conclusively reject the hypothesis that the grasslands are Pleistocene relicts that have declined throughout the Holocene; nonetheless, an explanation more consistent with the evidence overall is that the grasslands must have had periods of expansion during the Holocene, probably as a consequence of severe fires that have destroyed patches of rain forest.

Under future climate drought-induced tree mortality may result in the contraction of species ranges and the reorganization of community composition where abundant and peripheral species exchange their patterns of dominance. Predicting these changes will be challenging because the future suitable habitat may be a mismatch for the current bioclimatic envelope because of discrepancies between the realized and fundamental niche. Here we evaluate the extent of the discrepancy, as applied to tree species in relation to their relative field-recorded drought sensitivities and their observed range-wide environmental moisture envelopes. The hypothesis tested was that different species levels of drought-induced damage at sites where they co-occur will be positively associated with the minimum moisture availability in the most drought-prone part of each species current geographic range. We tested the hypothesis using drought damage measurements for 13 Australian Myrtaceae (including Eucalyptus) tree species at a site where all co-occur, together with 120 years of climate data across their geographical ranges. With limited statistical power the results generated only modest support for the hypothesis suggesting limited capacity to predict future distributions under climate change scenarios. In spite of the poor dispersal capacities of Eucalyptus and allied genera, but consistent with knowledge of breeding systems and genetic variability within Eucalyptus, the findings also suggest that many species have a capacity for rapid adaptive response to climate change, including the vicissitudes of the late Quaternary.

Surveying Savannas Savannas are structurally similar across the three major continents where they occur, leading to the assumption that the factors controlling vegetation structure and function are broadly similar, too. Lehmann et al. (p. 548 ) report the results of an extensive analysis of ground-based tree abundance in savannas, sampled at more than 2000 sites in Africa, Australia, and South America. All savannas, independent of region, shared a common functional property in the way that moisture and fire regulated tree abundance. However, despite qualitative similarity in the moisture–fire–tree-biomass relationships among continents, key quantitative differences exist among the three regions, presumably as a result of unique evolutionary histories and climatic domains.

The value of distinguishing between plant species regarded as ‘native’ and ‘alien’ has special relevance in the island continent of Australia, where European settlement was a springboard for human-assisted plant dispersal. The year of European settlement is proposed here as providing a distinction between a ‘native’ and ‘naturalised’ flora and is applied for the entire Australian flora of vascular plants. Herbarium collections and ecological criteria were employed to determine the status of 168 species of ambiguous origin. The date of 1788 proved to be a relatively straightforward criterion to assign native and naturalised status and the origin of only 27 plant species remains ambiguous. The dispersal of plants between continents is an ongoing process but European settlement of the Australian continent represents a very sharp biogeographic event for the Australian flora and provides a straightforward criterion for determining the ‘naturalised’ species.

The rapid spread of pastoralism across Australian and North American rangelands and the lack of reference sites mean that recurring arguments about the cause and magnitude of landscape change are frustrated by the rarity of records that predate the critical watershed of European settlement. The journals of European explorers from the 1840s are the first written descriptions of inland Australia. Prevailing paradigms based on a synthesis of published material relating to five key themes of environmental change are presented: vegetation structure, fire regimes, waterhole permanence, macropod abundance and medium-sized mammal assemblages. Six hypotheses relating to these themes were tested against the explorer record for inland eastern Australia. Nearly 4500 observations from fourteen journals spanning twelve expeditions between 1844 and 1919 were geo-referenced, using landscape features, distances, bearings and latitudes, combined with topographic maps and high-resolution satellite imagery. Careful evaluation of the record suggests little change in broad vegetation structure or waterhole permanence, running counter to prevailing paradigms. The sparse observations of fire suggest burning was infrequent and mostly restricted to creek-lines and higher-rainfall grasslands in the east and north of the study area and spinifex-dominated vegetation. Kangaroos were apparently uncommon in semi-arid areas where they are abundant today. The journals contain important observations of medium-sized mammals that are now extinct or rare. Our results highlight the importance of accurate geo-referencing compiled from entire journals of multiple explorers and contrasting the record with contemporary observation. Systematic evaluation of the explorer record for a region can provide ecological insights that are difficult to obtain by other means, and can be used to test prevailing assumptions common to arid systems that have been subject to abrupt management upheaval.

Aim Comparative analyses of fire regimes at large geographical scales can potentially identify ecological and climatic controls of fire. Here we describe Australia’s broad fire regimes, and explore interrelationships and trade-offs between fire regime components. We postulate that fire regime patterns will be governed by trade-offs between moisture, productivity, fire frequency and fire intensity. Location Australia. Methods We reclassified a vegetation map of Australia, defining classes based on typical fuel and fire types. Classes were intersected with a climate classification to derive a map of ‘fire regime niches’. Using expert elicitation and a literature search, we validated each niche and characterized typical and extreme fire intensities and return intervals. Satellite-derived active fire detections were used to determine seasonal patterns of fire activity. Results Fire regime characteristics are closely related to the latitudinal gradient in summer monsoon activity. Frequent low-intensity fires occur in the monsoonal north, and infrequent, high-intensity fires in the temperate south, demonstrating a trade-off between frequency and intensity: that is, very high-intensity fires are only associated with very low-frequency fire regimes in the high biomass eucalypt forests of southern Australia. While these forests occasionally experience extremely intense fires (> 50,000 kW m), such regimes are exceptional, with most of the continent dominated by grass fuels, typically burning with lower intensity (< 5000 kW m). Main conclusions Australia’s fire regimes exhibit a coherent pattern of frequent, grass-fuelled fires in many differing vegetation types. While eucalypts are a quintessential Australian entity, their contribution as a dominant driver of high-intensity fire regimes, via their litter and bark fuels, is restricted to the forests of the continent’s southern and eastern extremities. Our analysis suggests that the foremost driver of fire regimes at the continental scale is not productivity, as postulated conceptually, but the latitudinal gradient in summer monsoon rainfall activity.