Background Alternative stable state theory holds that disturbance thresholds can drive transitions between distinct vegetation types that exist under otherwise similar environmental settings. Recent investigations in arid Australia have presented compelling evidence for the existence of fire-mediated alternative stable states (FMASS) in various shrubland-grassland communities. These studies have explored edaphic factors contributing to boundaries. However, research is lacking on vegetation flammability characteristics promoting or retarding fire.Aims Investigate whether the shoot flammability of two woody species associated with fire-sensitive vegetation, Acacia aptaneura and Aluta maisonneuvei, is lower than co-occurring fire-promoting hummock grasses Triodia basedowii and T. pungens.Methods Flammability assessments on a plant grill tested for statistically significant differences between species.Key results A. aptaneura ignited more slowly, burned at lower temperatures and self-extinguished more rapidly than the other species, consistent with a low-flammability strategy. In contrast, no significant differences existed between A. maisonneuvei and the Triodia species across flammability traits. Reduced flammability in A. aptaneura was associated with higher shoot moisture content, lower biomass and reduced dead material retention.Conclusions and implications The findings indicate that desert plants display contrasting flammability syndromes, supporting the hypothesis that fire acts as a selective force shaping shoot traits and reinforcing vegetation boundaries in arid ecosystems.
Context Investigations into the life history strategies of organisms in ecosystems prone to fires are essential for effective fire impact management. In Australia, fire severity is expected to increase under anthropogenic climate change (ACC), therefore understanding plant responses to this fire regime element is essential for developing conservation-focused burning practices. Aims Assess the recruitment response of golden-top wattle (Acacia mariae) to varying fire severities (high, low and unburnt) in the semi-arid Pilliga forest in Northern Inland New South Wales. Investigate seedbank dynamics and germination biology to inform post-fire recruitment patterning. Methods Longitudinal seedbank studies were performed to understand seedbank dynamics and the associated influence on post-fire regeneration. A laboratory trial was conducted to assess the effects of heat shock and incubation temperature on seed germination. Field surveys were conducted at four sites to assess fire severity impacts and evaluate spatial variability in post-fire recruitment after the 2018 Gibbican Rd wildfire. Key results Recruitment varied among sites but was highest in shrubs burned by high-severity fire (5.8 seedlings/shrub), followed by low-severity fire (0.8 seedlings/shrub) and unburnt shrubs (0.1 seedlings/shrub). Over 5 years, seedbank densities fluctuated markedly, peaking in 2021 following a major seeding event but declined rapidly thereafter. Germination was optimised when seeds underwent heat shock at temperatures between 100 and 140°C and incubated at warm temperatures. Conclusions Acacia mariae germination is promoted by heat stimulation, explaining why high intensity burns with higher soil temperatures enhance recruitment. Differences in seedbank densities at the time of fire may account for varied recruitment across landscapes. Overall, A. mariae regenerates well after high-severity fires but poorly after low-severity fires, indicating that the species may be resilient to increased fire severity under ACC but struggle under current widespread low-severity prescribed management burning regimes.
After collecting the seeds, they are passed through flames.The seeds are then softened in water that has been heated with hot stones.After this, the seeds are cleaned in a wooden dish, ground on a millstone, cooked and eaten.Yes, this is really good food.Yalti Napangarti
Precipitation variability and heatwaves are expected to intensify over much of inland Australia under most projected climate change scenarios. This will undoubtedly have impacts on the biota of Australian dryland systems. However, accurate modelling of these impacts is presently impeded by a lack of empirical research on drought/heatwave effects on native arid flora and fauna. During the 2018-2021 Australian drought, many parts of the continent's inland experienced their hottest, driest period on record. Here, we present the results of a field survey in 2021 involving indigenous rangers, scientists and national parks staff who assessed plant dieback during this drought at Uluru-Kata Tjuta National Park (UKTNP), central Australia. Spatially randomized quadrat sampling of eight common and culturally important plants indicated the following plant death rates across UKTNP (in order of drought susceptibility): desert myrtle (Aluta maisonneuvei subsp. maisonneuvei) (91%), yellow flame grevillea (Grevillea eriostachya) (79%), Maitland's wattle (Acacia maitlandii) (67%), waxy wattle (A. melleodora) (65%), soft spinifex grass (Triodia pungens) (53%), mulga (A. aneura) (42%), desert oak (Allocasuarina decaisneana) (22%) and quandong (Santalum acuminatum) (0%). The sampling also detected that seedling recruitment was absent or minimal for all plants except soft spinifex, while a generalized linear mixed model (GLMM) indicated two-way interactions among species, plant size and stand density as important predictors of drought survival of adult plants. A substantial loss of biodiversity has occurred at UKTNP during the recent drought, with likely drivers of widespread plant mortality being extreme multi-year rainfall deficit (2019 recorded the lowest-ever annual rainfall at UKTNP [27 mm]) and record high summer temperatures (December 2019 recorded the highest-ever temperature [47.1 & DEG;C]). Our findings indicate that widespread plant death and extensive vegetation restructuring will occur across arid Australia if the severity and frequency of droughts increase under climate change.
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 relationships that control seed production in trees are fundamental to understanding the evolution of forest species and their capacity to recover from increasing losses to drought, fire, and harvest. A synthesis of fecundity data from 714 species worldwide allowed us to examine hypotheses that are central to quantifying reproduction, a foundation for assessing fitness in forest trees. Four major findings emerged. First, seed production is not constrained by a strict trade-off between seed size and numbers. Instead, seed numbers vary over ten orders of magnitude, with species that invest in large seeds producing more seeds than expected from the 1:1 trade-off. Second, gymnosperms have lower seed production than angiosperms, potentially due to their extra investments in protective woody cones. Third, nutrient-demanding species, indicated by high foliar phosphorus concentrations, have low seed production. Finally, sensitivity of individual species to soil fertility varies widely, limiting the response of community seed production to fertility gradients. In combination, these findings can inform models of forest response that need to incorporate reproductive potential.
The predator satiation (PS) hypothesis of masting holds that seeding periodicity among plant populations enhances seed survival by starving granivores during low-output periods and satiating reduced consumer populations during mast (high-output) years. Although well-studied in the northern hemisphere and in New Zealand, the PS hypothesis has received scant research attention in Australia. This is despite vegetation communities across nearly half the continent being dominated by masting species subject to high levels of seed predation (e.g. mulga [Acacia aneura] shrublands and spinifex [Triodia spp.] grasslands). Here, phenological monitoring and experimental testing of the PS hypothesis in the desert masting grass Triodia pungens (soft spinifex) occurred over 10 years at Deep Well station, central Australia. Field evidence supported the hypothesis that masting enhances seed escape from predators, as mean proportion seed survival at experimental bait stations was significantly greater during mast years (0.38 in 2012 and 0.33 in 2017) than during inter-mast years (0.01 in 2016 and 2018). The possibility that seed decay as opposed to consumption affected results was controlled for by a deterioration experiment that indicated no significant loss of seed viability after 6-months burial. The results support the hypothesis that masting in T. pungens is an adaptive trait related to the satiation of seed predators. However, whether masting enhances seed escape because predators are satiated at higher seed densities (i.e. masting causes a predator functional response) and/or because frequent low-output periods reduce predator populations and make satiation more likely (i.e. a numerical predator masting response), remains unresolved. Aside from T. pungens, there are numerous other plants of the Australian arid zone that experience high levels of granivory and display masting. Seed predation may be a more important selective force acting on arid Australian plant reproduction than previously thought.
Lack of tree fecundity data across climatic gradients precludes the analysis of how seed supply contributes to global variation in forest regeneration and biotic interactions responsible for biodiversity. A global synthesis of raw seedproduction data shows a 250-fold increase in seed abundance from cold-dry to warm-wet climates, driven primarily by a 100-fold increase in seed production for a given tree size. The modest (threefold) increase in forest productivity across the same climate gradient cannot explain the magnitudes of these trends. The increase in seeds per tree can arise from adaptive evolution driven by intense species interactions or from the direct effects of a warm, moist climate on tree fecundity. Either way, the massive differences in seed supply ramify through food webs potentially explaining a disproportionate role for species interactions in the wet tropics.
The diaspores of Lepidosperma Labill. (Cyperaceae) have thickened perianth members persistent at the base of the fruit, which are generally assumed to form a unique type of elaiosome but this assumption has not been tested rigorously. We tested whether the perianth provides a lipid-rich food reward and improves diaspore removal by ants in three species of Lepidosperma. We measured (i) the lipid and fatty acid composition of the fruit and perianth of two species of Lepidosperma, and of the seed and aril of two species of Acacia (known myrmecochores), (ii) the relative attractiveness to ants of the perianth in three species of Lepidosperma, and (iii) the relative attractiveness to ants of the diaspores of the same species of Lepidosperma compared with the two species of Acacia. We found that (i) Lepidosperma diaspores show traits consistent with myrmecochory, particularly the high lipid content (∼12–60%) and fatty acid profile of perianth material, (ii) isolated perianth members were removed in greater numbers over all times than were diaspores only (i.e. with perianth removed) in two species of Lepidosperma (n = 100, P = 0.035 and 0.047), whereas the difference was equivocal in the third species (n = 100, P > 0.05), and (iii) Lepidosperma and Acacia diaspores were removed in similar numbers over time (n = 100, P > 0.5). Seven species of diaspore-removing ant were observed, with Rhytidoponera metallica accounting for ∼50% of observed removals. We conclude that the perianth members of Lepidosperma are an elaiosome that provides a lipid-rich food reward.
Large, high-severity wildfires, or “megafires,” occur periodically in arid Australian spinifex (Triodia spp.) grasslands after high rainfall periods that trigger fuel accumulation. Proponents of the patch-burn mosaic (PBM) hypothesis suggest that these fires are unprecedented in the modern era and were formerly constrained by Aboriginal patch burning that kept landscape fuel levels low. This assumption deserves scrutiny, as evidence from fire-prone systems globally indicates that weather factors are the primary determinant behind megafire incidence, and that fuel management does not mitigate such fires during periods of climatic extreme. We reviewed explorer’s diaries, anthropologist’s reports, and remotely sensed data from the Australian Western Desert for evidence of large rainfall-linked fires during the pre-contact period when traditional Aboriginal patch burning was still being practiced. We used only observations that contained empiric estimates of fire sizes. Concurrently, we employed remote rainfall data and the Oceanic Niño Index to relate fire size to likely seasonal conditions at the time the observations were made. Numerous records were found of small fires during periods of average and below-average rainfall conditions, but no evidence of large-scale fires during these times. By contrast, there was strong evidence of large-scale wildfires during a high-rainfall period in the early 1870s, some of which are estimated to have burnt areas up to 700,000 ha. Our literature review also identified several Western Desert Aboriginal mythologies that refer to large-scale conflagrations. As oral traditions sometimes corroborate historic events, these myths may add further evidence that large fires are an inherent feature of spinifex grassland fire regimes. Overall, the results suggest that, contrary to predictions of the PBM hypothesis, traditional Aboriginal burning did not modulate spinifex fire size during periods of extreme-high arid zone rainfall. The mechanism behind this is that plant assemblages in seral spinifex vegetation comprise highly flammable non-spinifex tussock grasses that rapidly accumulate high fuel loads under favorable precipitation conditions. Our finding that fuel management does not prevent megafires under extreme conditions in arid Australia has parallels with the primacy of climatic factors as drivers of megafires in the forests of temperate Australia.
Questions Buffel grass (Cenchrus ciliarisL.) 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.
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.
Background and AimsPlant 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.MethodsPhenological 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.Key ResultsTriodia 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.ConclusionsFires 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.
Alternative stable state theory predicts that different disturbance regimes may support contrasting ecosystem states under otherwise analogous environmental conditions. In fire-prone systems, this theory is often invoked to explain abrupt ecotones, especially when adjacent vegetation types have contrasting flammabilities and differing tolerances to pyric perturbation. Despite being well-documented in forest-savanna transitions, unambiguous examples of fire-driven alternate stable states (FDASS) in arid systems are rare. The current study examined whether flammable spinifex (Triodia spp.) grasslands and fire-sensitive waputi (Aluta maisonneuvei subsp. maisonneuvei) shrublands in Australia's Gibson Desert represent FDASS. Specifically, analyses of soil and topographic variables assessed whether environmental differences explain habitat zonation. To determine whether different flammabilities of Aluta and Triodia systems may perpetuate alternative states via vegetation-fire feedback processes, community-level fuelloads were quantified to provide an indirect measure of flammability. To determine the propensity for fire to trigger 'state-shifting', community responses to a single high-severity fire were evaluated. Habitat segregation did not relate to between-site environmental differences, and the fuel-load study indicated that the more pyrophytic community (Triodia grassland) is more flammable, and hence more likely to experience higher frequency fire-cycles. Fire was identified as a potential vector of 'state-change', because although both systems regenerated well after fire, Triodia reproduced more prolifically at a younger age than Aluta, and hence should tolerate shorter fire-return intervals. In the absence of between-community topographic and edaphic differences, or herbivores that consume either plant, it is likely that Aluta shrublands and Triodia grasslands represent fire-mediated alternative equilibrium states.
In arid Australia, fires in different seasons often result in markedly different recruitment rates of woody plants, and this can have important and long-lasting impacts on post-fire community structure and composition. The current study investigated ecological mechanisms behind this effect in four widespread arid Acacia species: Acacia aptaneura, Maslin & J.E.Reid Acacia kempeana F.Muell., Acacia maitlandii F.Muell. and Acacia melleodora Pedley. Specifically, the study examined whether increased recruitment after summer compared with winter burning relates to (1) higher soil temperatures during summer fires having increased capacity to overcome dormancy of seeds with heat-stimulated germination; (2) warmer soil temperature conditions after summer fires providing more favourable incubation temperatures for germination; and/or (3) summer fires coinciding with seasonal fluxes in seedbank densities, which may occur in response to granivory and/or rapid rates of seed deterioration after dispersal. Results supported hypotheses (1) and (2), as germination of all species responded positively to heat shock and warmer incubation temperatures. Some support was also demonstrated for hypothesis (3), as seedbank densities were shown to fluctuate seasonally, most likely in response to strong granivory. This multi-species study provides insights into mechanisms behind enhanced shrub recruitment after arid zone summer fires; and reinforces the notion that season of burn can be a strong determinant of regeneration trajectories of woody plants after fire.
PREMISE OF THE STUDY:Fire typically triggers extensive regeneration of plants with heat-stimulated germination by causing short periods of intense soil heating. If plants with heat-stimulated germination are also subject to seed predation and display mast-seeding cycles, postfire recruitment may be contingent on the seedfall density of prefire masts, and on whether granivores are satiated at the time of fire.METHODS:We conducted a longitudinal seedbank study and a mensurative field experiment in central Australia to examine whether fire and the variation in seedfall density across sites in a mast year interact to influence recruitment of slender mulga (Acacia aptaneura), an iteroparous masting shrub with heat-stimulated germination.KEY RESULT:The seedbank study showed seedbank pulsing after masting, with mean seed counts in the upper 4-cm soil layer being 132.8 seeds/m2 12-mo after a dense seedfall, but only 3.8 seeds/m2 following a year with no seed production. Consistent with this, recruitment increased postfire at sites where denser seedfall had occurred during the preburn mast year. Conversely, little recruitment occurred at unburnt populations, irrespective of prefire seedfall density.CONCLUSIONS:We attribute our findings to: (1) elevated soil temperatures during fires stimulating germination of heat-cued seeds; and (2) granivore satiation following masting facilitating assimilation of seeds into the soil seedbank. These results highlight the importance of rare seed-input events for regeneration in fire-prone systems dominated by masting plants, and provide the first example from an arid biome of fire interacting with masting to influence recruitment.
Fire intensity is recognised as an important driver of regeneration dynamics in forest and shrubland vegetation types, but its effects on recruitment processes in arid grasslands are poorly understood. Here, we used fire severity as a surrogate measure of fire intensity, and compared post-fire seedling recruitment from arid Triodia pungens (soft spinifex) plots burnt by low-severity experimental fires against those burnt by a high-severity wildfire. To explain T. pungens recruitment patterns, we also: (1) conducted a longitudinal depth distribution study of soil seedbank densities, and (2) carried out a lethal-temperature experiment on T. pungens seeds. High-severity burning was associated with reduced T. pungens recruitment compared with low-severity fire, and this relationship was attributed to the low lethal temperature thresholds of seeds and the adverse impacts of elevated soil temperatures during high-severity fire on the shallow soil seedbank. Among other species in the community, there were varied recruitment responses to fire severity. Overall, our results indicate that a strong link exists between fire severity and recruitment in arid spinifex grassland, though the association is variable among species, and dependent on the seedbank attributes, germination biologies and lethal-temperature thresholds of seeds of individual species.
Members of the widespread arid Australian mulga (Acacia aneura) complex are fire-sensitive shrubs or small trees that can resprout epicormically following low-severity burning, but are readily killed by high-severity fire. The seeds of many species of mulga are stimulated to germinate by heat during burning, although post-fire regeneration rates are unpredictable. Here, we investigated whether variability in post-fire mulga recruitment relates to the relationship between fire severity and soil heating during fire, which may kill, leave unaffected, or stimulate the germination of buried seeds. This hypothesis was examined in central Australia on slender mulga (A. aptaneura), by experimentally investigating (a) seedling recruitment rates under different fire severity classes, (b) the germination and lethal temperature thresholds of seeds, (c) soil temperatures during fires of different severity classes and (d) the emergence depths of seedlings beneath high- and low-severity burnt plants. We found that post-fire recruitment was significantly lower beneath low-severity burnt and unburnt plants than high-severity burnt plants. This result was explained by the finding that maximum germinability of mulga seeds occurs after heating to between 80 and 100 °C, and that these temperatures are not achieved in unburnt patches or low-severity burns at depths where the majority of the seed bank is known to occur. Despite the increased regeneration observed after high-severity fire, post-fire recruitment was highly variable between sites, independent of fire severity. This indicates that while heat-stimulated germination may confer on mulga a risk-spreading strategy to a range of fire severities, post-burn recruitment may not always offset high adult death rates following high-severity fire.
Mast seeding, the intermittent production of large synchronised seed crops among plant populations, is a phenomenon that occurs at exceptionally long intervals in spinifex grasses (Triodia spp.) from arid regions of Australia. This is despite the reliance of these fire-sensitive plants on seeds for post-fire regeneration, and that spinifex grasslands rate among Australia’s most flammable ecosystems. The proximate causes and possible adaptive functions of masting in seven species of spinifex from arid regions within the 350-mm rainfall isohyet were investigated. Specifically, the seed set percentages of 79 specimens collected between 1947 and 2012 were related to the following environmental covariates: antecedent rainfall over 6, 12 and 36 months, relative humidity, and the number of days above 40°C and below 0°C during anthesis. Given the potential importance of seeding events for post-fire regeneration, it was also investigated whether masting in Triodia could represent a fire-related form of environmentally predictive masting, by testing whether high-yield years corresponded to years of increased fire occurrence. Examination of the dataset showed that 43% of specimens contained completely aborted inflorescences (0% seed fill), while seed set ranged from 2 to 69% in the remaining specimens. High levels of insect activity were also found, with 42% of specimens showing evidence of insect occupation. Statistical analyses showed that the main environmental driver of seed set was high precipitation over the previous 12 months, and that high-yield years were strongly related to years of increased fire likelihood. The number of days over 40°C was a weakly significant driver of yield, while the remaining covariates were not significant. It is hypothesised that intermittent reproduction by Triodia is a fire-related form of environmentally predictive masting, which maximises chances of post-fire regeneration by satiating seed predators during flammable periods (i.e. after heavy rain years). Furthermore, it is suggested that non-viable flower crops after initial low rainfalls may have an adaptive function, by diluting pre-dispersal seed predator densities with ‘decoy’ ovules that do not mature and lead to the starvation of developing larvae.