Search

Banksias are iconic Australian plants, with a Gondwanan origin. Their specialised roots help survival on low‐phosphorus soils, and many species have reproductive cycles adapted to fire. They are trophically important in many of Australia’s native forests, woodlands and heathlands, providing nectar, pollen and seeds for many species of birds, mammals and invertebrates. While legacies of land use have reduced the historic extent of some Banksia species, more recent declines have raised additional concerns about their persistence in some landscapes. A range of factors are considered to be impacting Banksia persistence (Lamont et al. 2007), including habitat loss and fragmentation (e.g. Miller et al. 2020), increased fire frequency (e.g. Bradstock et al. 1997) and climate change (e.g. Steel et al. 2019), but there is no consensus about how these interacting factors may be driving declines, and how widespread these declines may be. The challenges facing Banksia species conservation in the south‐eastern state of Victoria were the focus of an online workshop in May 2020. The workshop brought together researchers and land managers from Victorian and interstate universities, Victorian government agencies and volunteer land management groups to share their knowledge of the threats facing banksias, and document ideas to reverse declines. It was organised by Arthur Rylah Institute for Environmental Research (Department Environment, Land, Water and Planning), La Trobe University (Department of Ecology, Environment and Evolution) and Federation University (Centre for eResearch and Digital Innovation).

Many plant species have pollination and seed dispersal systems and evolutionary histories that have produced strong genetic structuring. These genetic patterns may be consistent with expectations following recent anthropogenic fragmentation, making it difficult to detect fragmentation effects if no prefragmentation genetic data are available. We used microsatellite markers to investigate whether severe habitat fragmentation may have affected the structure and diversity of populations of the endangered Australian bird-pollinated shrub Grevillea caleyi R.Br., by comparing current patterns of genetic structure and diversity with those of the closely related G. longifolia R.Br. that has a similar life history but has not experienced anthropogenic fragmentation. Grevillea caleyi and G. longifolia showed similar and substantial population subdivision at all spatial levels (global F'ST = 0.615 and 0.454; Sp = 0.039 and 0.066), marked isolation by distance and large heterozygous deficiencies. These characteristics suggest long-term effects of inbreeding in self-compatible species that have poor seed dispersal, limited connectivity via pollen flow and undergo population bottlenecks because of periodic fires. Highly structured allele size distributions, most notably in G. caleyi, imply historical processes of drift and mutation were important in isolated subpopulations. Genetic diversity did not vary with population size but was lower in more isolated populations for both species. Through this comparison, we reject the hypothesis that anthropogenic fragmentation has impacted substantially on the genetic composition or structure of G. caleyi populations. Our results suggest that highly self-compatible species with limited dispersal may be relatively resilient to the genetic changes predicted to follow habitat fragmentation.

Structurally complex forest provides important habitat for a diverse array of vertebrate fauna. Frequent fire can simplify forest structure, though topographic mitigation of fire effects could potentially preserve structurally more complex habitat within certain topographic locations of fire prone landscapes. Our study assessed whether the effects of fire frequency on forest structure (tree hollows, log volume, vegetation complexity) varied with topographic position. The effect of wildfire severity and intensive logging were also examined. Frequent fire reduced vegetation cover on ridges, but not in gullies. The risk of collapse (i.e. presence of fire scars) increased for large trees on frequently burnt ridges, but remained suppressed in gullies. Crown fire reduced hollow presence in dead trees (i.e. snags), but increased hollow presence in trees with a healthy crown. The volume of extensively decomposed logs was three times greater in gullies than ridges, but was unaffected by fire frequency. Intensive logging reduced the number of hollow bearing trees and increased the volume of extensively decomposed logs, though future declines in log volume are predicted due to bottlenecks in log input. Our results suggest that gullies may play a critical role in preserving structurally complex stands within frequently burnt temperate eucalypt forests. Protecting gullies from land clearing and intensive logging is likely to be an important step in maintaining key habitat features and associated fauna in these landscapes.

Log hollows provide important habitat for a range of vertebrate fauna. Despite this, little is known about the impact fire regimes have on this resource, or the role topography may play in preserving hollows through the mitigation of fire intensity. This study examined the effect different combinations of fire frequency and topography have on (i) the number of hollow bearing logs and (ii) the presence and size of hollows within logs. The influence of wildfire severity and logging were also examined. Hollow availability (i.e. density of hollow bearing logs and hollow presence within logs) was greatest at sites burnt at ‘low’ frequency. The density of hollow logs was greater in gullies, though the effect of fire frequency did not vary with topographic position. Hollows showing signs of internal fire charring typically had a greater entrance width than unburnt hollows, which suggests fire plays an important role in creating large hollows. The number of hollow bearing logs increased with logging intensity, due to unmerchantable timber being left in situ. Wildfire severity had little effect on log hollows. The results indicate that frequent burning may reduce hollow availability, though it is likely that gullies will still retain a high density of hollow bearing logs irrespective of burning, and may play an important role in preserving connectivity of this resource across landscapes.

Subject area Higher education leadership and planning. Study level/applicability Postgraduate/higher education. Case overview Professor Rob Whelan was appointed President of the University of Wollongong in Dubai (UOWD) from the University of Wollongong in Australia (UOW). Professor Whelan brought to the job in Dubai the perspective that public-good benefits flow from a comprehensive institution engaged with the larger community and these are led by academic staff members who produce research that serves the national interest. To apply this model to UOWD meant a thorough analysis of the organization in terms of both its culture and its broader environment. This case explores the various processes through which a new leader takes stock of an existing institution, identifies the potential for development in a particular direction, draws upon a range of stakeholders to refine the vision and develop it into a strategic plan, gains support for the plan, and then implements change through close collaboration with the institution's constituents. Expected learning outcomes This case can be used to explore a number of issues in leadership and management including: identifying the various internal and external stakeholders in a complex organization; analysing strategies for mobilization for change, including the assessment of inclusive versus exclusive approaches; reviewing the opportunity costs of change; and assessing types of leadership. Supplementary materials Teaching notes.

The frequency of hybridization in plants is context dependent and can be influenced by the local mating environment. We used progeny arrays and admixture and pollen dispersal analyses to assess the relative importance of pre-mating reproductive barriers and the local demographic environment as explanations of variation in hybrid frequency in three mapped hybrid zones of Eucalyptus aggregata and E. rubida. A total of 731 open-pollinated progeny from 36 E. aggregata maternal parents were genotyped using six microsatellite markers. Admixture analysis identified substantial variation in hybrid frequency among progeny arrays (0–76.9%). In one hybrid zone, hybrid frequency was related to pre-mating barriers (degree of flowering synchrony) and demographic components of the local mating environment (decreasing population size, closer proximity to E. rubida and hybrid trees). At this site, average pollen dispersal distance was less and almost half (46%) of the hybrid progeny were sired by local E. rubida and hybrid trees. In contrast, at the other two sites, pre-mating and demographic factors were not related to hybrid frequency. Compared to the first hybrid zone where most of the E. rubida (76%) and all hybrids flowered, in the remaining sites fewer E. rubida (22–41%) and hybrid trees (0–50%) flowered and their reproductive success was lower (sired 0–23% of hybrids). As a result, most hybrids were sired by external E. rubida/hybrids located at least 2–3 km away. These results indicate that although pre-mating barriers and local demography can influence patterns of hybridization, their importance can depend upon the scale of pollen dispersal.

The Ground Parrot (Pezoporus wallicus) is a rare and iconic endemic of heathlands in southern Australia. It is threatened by frequent and widespread fire. The species has been an integral element in the development of our understanding of the impacts of fire regimes in heathlands and is an integral part of conservation management of these fire-prone ecosystems. This long-term study documents the densities of Ground Parrots in three areas of long-unburnt habitat in southern New South Wales. Using area searches and aural surveys, we estimated densities of Ground Parrots at Barren Grounds Nature Reserve–Budderoo National Park (1983–2009), Beecroft Weapons Range (1997–2008) and Nadgee Nature Reserve (1995–2009). At each location, the species occurred in long-unburnt habitat (≥20 years post-fire), sometimes at high densities (≥2 birds per 10 ha). We recommend that, in south-eastern Australia, fire should not be used to manipulate the ecological functioning of habitat for the persistence of Ground Parrot populations and conclude that there should be area-specific adaptive management plans that specify how the important elements of the biodiversity will be conserved and how this will be measured.

The patterns of hybridization and asymmetrical gene flow among species are important for understanding the processes that maintain distinct species. We examined the potential for asymmetrical gene flow in sympatric populations of Eucalyptus aggregata and Eucalyptus rubida, both long-lived trees of southern Australia. A total of 421 adults from three hybrid zones were genotyped with six microsatellite markers. We used genealogical assignments, admixture analysis and analyses of spatial genetic structure and spatial distribution of individuals, to assess patterns of interspecific gene flow within populations. A high number of admixed individuals were detected (13.9-40% of individuals), with hybrid populations consisting of F(1) and F(2) hybrids and backcrosses in both parental directions. Across the three sites, admixture proportions were skewed towards the E. aggregata genetic cluster (x=0.56-0.65), indicating that backcrossing towards E. aggregata is more frequent. Estimates of long-term migration rates also indicate asymmetric gene flow, with higher migration rates from E. aggregata to hybrids compared with E. rubida. Taken together, these results indicate a greater genetic input from E. aggregata into the hybrid populations. This asymmetry probably reflects differences in style lengths (E. rubida: ~7 mm, E. aggregata: ~4 mm), which can prevent pollen tubes of smaller-flowered species from fertilizing larger-flowered species. However, analyses of fine-scale genetic structure suggest that localized seed dispersal (40 m) and greater clustering between hybrid and E. aggregata individuals may also contribute to directional gene flow. Our study highlights that floral traits and the spatial distributions of individuals can be useful predictors of the directionality of interspecific gene flow in plant populations.

Recruitment in plant populations is often tightly coupled to major disturbances such as fires. For species with persistent seed banks, fire-related cues may allow or enhance germination. The litter layer influences germination and may modify the impact of seed predators on seeds and seedlings. The litter layer is obviously affected by fire, providing one mechanism by which disturbance can determine recruitment. We tested the role of litter in the disturbance–recruitment coupling of two species with contrasting seed release timing after fire—Banksia serrata (canopy seed bank) and Telopea speciosissima (transient seed bank) by planting their seeds both early and late in the post-fire recruitment period (PRP) and manipulating litter density in orthogonal treatments. Vertebrate seed predators were excluded. Both species established more seedlings late in the PRP, although results were strongly influenced by very poor establishment at one site. Invertebrate seed predators consumed more T. speciosissima seeds in sites early (69.5%) than late in the PRP (51.2%), while consumption of B. serrata seeds was lower overall and comparable across sites (average 47.3%). Surprisingly, litter had very little effect on establishment and none on invertebrate seed predation, suggesting that other factors are more important. Recruitment was only loosely coupled to disturbance for the canopy seed bank species; for the transient seed bank species, the coupling was tighter but separated in time from the disturbance. Understanding both the strength and temporal aspects of the disturbance–recruitment coupling is necessary for appropriate management of plant functional diversity in fire-prone habitats.

Many plants regenerate after fire from a canopy-stored seed bank, in which seed are housed in fire resistant confructescences (cones) that remain on maternal plants. This strategy would be favoured if plants accumulate a sufficiently large and genetically diverse seed bank during interfire intervals. We use a 16-year demographic study and surveys of microsatellite variation to quantify and explain the rate of accumulation of genetic diversity within the canopy seed bank of the shrub Banksia spinulosa. Flowering and fruit set were highly variable. An initial sample in 1991 of 354 reproductively mature plants generated 426 cones over 16 years, of which only 55 cones from 40 maternal plants persisted until 2005. By genotyping seed from these 55 cones we demonstrated that genetic diversity accumulated rapidly within the seed bank. Resampling revealed that diversity was determined by the number, not the age, of cones. Cones were widely distributed among plants, outcrossing rates were high (mean tm = 1.00 ± 0.04) and biparental inbreeding low. Adults displayed little evidence of isolation by distance and the genotypic diversity of seed cohorts was independent of the density of neighbouring potential sires. We therefore estimate that within at least 13 individual years the number of cones produced per year (14-63) would have contained 100% of the adult genetic diversity. We conclude that a highly outcrossed mating system and relatively widespread pollen dispersal ensure the rapid development of a genetically diverse and spatially and temporally homogeneous seed bank.

Summary 1 Increased fire frequency is seen as a key threat to plant populations in Mediterranean-type ecosystems across the globe. Short inter-fire periods may exhaust soil-stored and fire-stimulated seed banks of fire-sensitive species, reducing actual and effective population sizes and eroding genetic diversity. 2 Here we used microsatellite genotyping to investigate the genetic impacts of repeated wildfires and, in particular, the contribution of above-ground genetic processes (seed and pollen dispersal) to the genetic structuring and composition of post-fire recruits in an isolated population of the fire-sensitive shrub Persoonia mollis ssp. nectens. 3 We tested the hypothesis that limited pollen and seed dispersal, in combination with the potentially patchy effects of fire at a fine scale within populations, would generate a highly structured population, a decline in genetic diversity after each fire and genetic heterogeneity between successive cohorts. 4 Wildfires killed all 25 adult plants in 1997 and, in 2001, killed all of the 476 seedlings remaining from the 1997 seedling cohort. Although there was no possibility of replenishment of the seed bank in the interval between fires, a second cohort of 381 seedlings emerged after the 2001 fire. 5 We found no evidence that successive fires produced either a decline in genetic diversity, as measured by allelic richness or expected heterozygosity, or the genetic differentiation of adult and successive seedling cohorts (Pairwise FST = −0.0125 to 0.0009). The seedling cohorts displayed less genetic structuring than anticipated. Spatial genetic structure was low, ranging from Sp = 0.02 in the 1997 seedlings to Sp = 0.06 in the 2001 seedlings, and using parentage analysis, we found that seedlings clustered under dead adults rarely reflected simple seed shadows. 6 Synthesis. Overall, we found that a numerically large seed bank with a bet-hedging strategy of staged seed germination, in combination with genetic mixing achieved by both pollen and seed dispersal, provides a powerful buffer against the negative impacts of frequent fire in P. mollis ssp. nectens.

†Background and Aims In Australia, honey-bees have invaded systems that evolved without social insect pollinators, where many plants are adapted to vertebrate pollination. Behavioural differences between pollinators are likely to influence mating patterns, but few studies have examined this empirically in long-lived, woody, perennials. It was shown previously that outcrossing rates in Grevillea macleayana vary among populations. Here tests were conducted to determine whether the behaviour of birds and honey-bees differed between a population previously found to be highly outcrossed and two inbreeding populations. †Methods Visit frequencies and movement patterns of the visitors to inflorescences at three sites over two seasons were compared. A caging experiment was used to test the effects of excluding birds on pollen removal from newly opened flowers and on pollen deposition on stigmas that had been washed clean. †Key Results Honey-bees were the most frequent visitors overall, but honeyeaters were more frequent visitors in the population previously found to have a high outcrossing rate than they were in either of the other populations. More visits by honeyeaters were from distant plants. Pollen removal did not vary greatly among sites, and was not affected by bird exclusion; however, more pollen was deposited on the stigmas of cleaned pollen presenters in the population previously observed to be highly outcrossing than in the other two. This high level of pollen deposition was reduced by experimental bird exclusion. †Conclusions Honey-bees were the most frequent visitors, by an order of magnitude, and excluding vertebrates revealed that bees were removing most of the pollen but deposited fewer pollen grains on stigmas. Birds were more frequent visitors at the site previously found to be outcrossing than the other two sites, and they moved further between plants and visited fewer inflorescences on a plant during a foraging bout than bees did. These characteristics of bird visits to G. macleayana would be sufficient to produce significant variation in outcrossing rates among sites.

Spatial patterns of fruit set within inflorescences may be controlled by pollination, nutrient allocation, or inflorescence architecture. Generally, flowers that have spatial and/or temporal precedence are more likely to set fruits. We sought to separate these factors by comparing patterns of fruit set on inflorescences of two species of Telopea (Proteaceae); one that flowers from the tip to the base of the rachis, the other from base to tip. In both species, most fruits were set at the top of the inflorescence (the last flowers to open for T. speciosissima) and this was extreme for T. mongaensis, where the top flowers open first. Fruit set was not generally limited by inadequate pollination for either T. mongaensis or T. speciosissima, as hand pollinations did not increase fruit set and many abscised flowers contained pollen tubes. In T. speciosissima, we tested whether removal of developing topmost fruits would ‘release’ those that had initiated but not yet aborted lower down. There was no significant effect. Plant hormones can increase the degree to which a developing fruit is a sink for nutrients, so we applied cytokinin to the developing lower fruits on some inflorescences. There was no significant effect of the hormone treatment. We conclude that temporal precedence may contribute to the skewed pattern of fruit set in T. mongaensis, because there was an extreme concentration of fruit set on the distal part of the inflorescences, but it cannot explain this pattern of fruit set in T. speciosissima, where the distal flowers are the last to open. Some other process must therefore constrain fruit set to the topmost flowers in an inflorescence. While cytokinin application had no significant effect, the power of this experiment was low and we consider that the hypothesis of hormonal control is worth further exploration.

Litter accumulation after fire influences the magnitude of seed predation and seed germination. How litter accumulation and patchiness influence postfire seedling recruitment is poorly known. Species with persistent seed banks have seeds available for germination in the immediate postfire period. In contrast, plants with transient seed banks must flower after fire to place seeds in the postfire habitat. In southeastern Australian sclerophyll forests, most seedling recruitment occurs within 3 yr after fire. We found that less litter had accumulated in sites

Summary 1. Habitat fragmentation can alter the relative frequency of cross-compatible species within an area, which can affect the levels of interspecific hybrid production and reduce the viability of small populations through genetic and demographic swamping. For 18 populations of Eucalyptus aggregata, we examined the effects of absolute and relative population size (compared with its congeners E. rubida, E. viminalis and E. dalrympleand) on hybrid production, genetic diversity and subsequent seed production and seedling performance. 2. Relative population size was strongly negatively correlated with rates of hybrid seed production, suggesting increased hybridization when the potential sources of interspecific pollen outnumber the sources of intraspecific pollen for E. aggregata trees. 3. Genetic diversity was negatively correlated with relative population size which suggests that hybridization may maintain diversity lost through bottlenecks and drift following reductions in population size. However, the presence of fertile hybrid adults, and introgressed leaf traits within populations exhibiting high hybridization rates, suggests that small E. aggregata populations may be vulnerable to genetic swamping by common congeners. 4. Amongst an array of population parameters (population sizes, genetic diversity and inbreeding), seed production was only positively correlated with relative population size, whereby sites with low relative population sizes tended to produce fewer seed. This could be due to the action of pre-zygotic barriers which removes inviable hybrid genotypes as levels of interspecific pollen flow increase. 5. Germination and survivorship displayed a similar positive correlation with relative population size, suggesting post-zygotic hybrid breakdown may also contribute towards to demographic swamping of remnant populations. 6. Synthesis. Our results suggest that relative population size is an important parameter determining rates of hybrid production, seed production and seedling performance. Furthermore, relative population size has stronger effects on population fecundity than absolute population size, genetic diversity and levels of inbreeding. Relative population sizes > 0.5 (i.e. at least equal frequencies of parentals) may be required to avoid the deleterious effects of genetic and demographic swamping on the viability of rare species.

Human activities can promote increased hybridization in the genus Eucalyptus with potentially detrimental consequences for the persistence of rare species. However, many hybrid combinations have not been investigated with combined use of genetic markers and morphology. We assessed the efficiency of the STRUCTURE program and morphological intermediacy for identifying hybrids between the uncommon tree, Eucalyptus aggregata, which putatively hybridizes with the common congeners, E. rubida and E. viminalis in south-eastern Australia. We sampled 1,005 seedlings across 27 populations, all seedlings were genotyped at 6 allozyme loci and scored for 22 stem and leaf characters. Both marker sets confirmed that E. aggregata is hybridizing with both E. rubida and E. viminalis. Allozymes revealed hybrids from E. aggregata trees in 88% of populations and hybrids comprised 7.3% of all seedlings. Both genetics and morphology indicated that ~50% were likely to be F1 hybrids, and both simulations and morphological characteristics indicated that the remainder were mostly backcrosses. Morphological analysis correctly distinguished 71% of F1 hybrids from parentals and was least accurate when dealing with potential backcrosses (50% success). Hence, techniques using genetic data (no prior information) and the assessment of appropriate admixture thresholds through simulations provided the most accurate estimates of hybrid frequency. In this study, potential introgression and the high frequency of hybrids in small populations (~30%), suggests that hybridization should be considered in the management and conservation of E. aggregata.

Remnant plants in urban fringes and native plants in gardens have the potential to contribute to the conservation of threatened plants by increasing genetic diversity, effective size of populations, and levels of genetic connectedness. But they also pose a threat through the disruption of locally adapted gene pools. At Hyams Beach, New South Wales, Australia, four bushland stands of the rare shrub, Grevillea macleayana McGillivray, surround an urban area containing remnant and cultivated specimens of this species. Numbers of inflorescences per plant, fruits per plant, and visits by pollinators were similar for plants in urban gardens and bushland. Urban plants represented a substantial but complex genetic resource, displaying more genetic diversity than bushland plants judged byH(e), numbers of alleles per locus, and number of private alleles. Of 27 private alleles in urban plants, 17 occurred in a set of 19 exotic plants. Excluding the exotic plants, all five stands displayed a moderate differentiation (F(ST)= 0.14 +/- 0.02), although the urban remnants clustered with two of the bushland stands. These patterns may be explained by high levels of selfing and inbreeding in this species and by long-distance dispersal (several seeds in the urban stand were fathered by plants in other stands). Genetic leakage (gene flow) from exotic plants to 321 seeds on surrounding remnant or bushland plants has not occurred. Our results demonstrate the conservation value of this group of urban plants, which are viable, productive, genetically diverse, and interconnected with bushland plants. Gene flow has apparently not yet led to genetic contamination of bushland populations, but high levels of inbreeding would make this a rare event and difficult to detect.

Legislative listing schemes, under which the listing of a species as threatened automatically triggers command regulation and/or recovery planning, raise significant issues for policy makers. In this paper, we explore strategies for factoring considerations beyond the empirical assessment of a species’ conservation status into the resource allocation decisions that flow from listing. Even in threatened species legislation that appears to prioritise species conservation over socio-economic considerations by creating an automatic nexus between listing and conservation response, there are significant pressure valves that allow the latter to exercise a significant influence on decisions in practice. We critically examine two other techniques currently used in legislation that allow a broader range of considerations to be factored into resource allocation decisions: abandoning the automatic triggering of resource allocation by listing; and taking into account a broader range of considerations in the listing decision itself. We conclude by outlining the framework for a strategic approach to the allocation of conservation resources. This has three limbs to it: recovery plans that identify what needs to be done to bring about recovery, in addition to what available resources will allow us to do; a system for prioritising between the implementation of recovery plans; and the integration of threatened species conservation into strategic land use planning processes.

Native plants in gardens can potentially aid conservation by contributing to genetic diversity and buffering small and otherwise isolated populations from extinction. However, gene flow from such plantings may threaten the genetic integrity of natural populations. We assessed the morphological and genetic diversity of garden plants in an urban population of Grevillea macleayana in south-eastern Australia. There were two main groups of garden plants: some similar to plants in nearby natural populations; others with unusual morphology. Multivariate analysis of morphological characters separated these groupings, which were confirmed by genetic analysis. Both groups produced seeds and flowering phenologies overlapped, indicating a potential for gene flow. Hand pollination showed that plants in each group could fertilize flowers of the other. Thus, these garden plants contributed to genetic variation in an urban/bushland metapopulation but there was potential for gene flow from the unusual plants. Unless carefully managed, garden plants may therefore cause disruption of the genetic integrity of nearby natural populations.

Summary Royal National Park, Australia's oldest national park, is a significant reserve for conservation of the flora and fauna that are characteristic of the Hawkesbury Sandstone in New South Wales. Since at least 1974, Phytophthora Root Rot (caused by Phytophthora cinnamomi) has been known to occur in the Park, but there is no knowledge of the extent of infestation or the potential impacts of the disease within the Park. This study investigated the distribution of the pathogen within Royal National Park at two scales: a systematic survey by vegetation type, and a targeted survey of populations of Waratah and Spear Grass-tree. These two species are known to be susceptible to Phytophthora Root Rot and are therefore potential indicators of the impact of the pathogen on vegetation in Royal National Park. Phytophthora cinnamomi was recovered from all vegetation types sampled but most commonly in heathland/open scrub vegetation. The pathogen was easily recovered from sites containing Spear Grass-tree, but was not isolated from any sites containing Waratah. Because of the widespread distribution of P. cinnamomi, we conclude that hygiene measures will be of little use to prevent the spread of the pathogen within Royal National Park. Monitoring of the occurrence and spread of disease symptoms in plants and applying phosphite to protect susceptible rare or threatened flora may be the most appropriate management options.

Chrysanthemoides monilifera ssp. rotundata is an invasive plant in eastern Australia. It produces large quantities of fleshy fruits, which are dispersed by birds and mammals, and has the potential to alter ecological processes in native plant communities in several ways. Seed dispersal of native plants growing amongst C. monilifera could be decreased (if C. monilifera is effective in competing for limited seed dispersers), increased (if C. monilifera-infested vegetation supports more seed dispersers), or be unchanged (if there is sufficient separation in fruiting time or dispersal agents between the species, or if dispersers are not limiting). We compared the rates of removal of fruits of native plants (Monotoca elliptica and Elaeocarpus spp.) from experimental stations in C. monilifera stands, in uninfested coastal vegetation, and in vegetation from which C. monilifera had been eliminated with herbicide. The rate of removal of fruits differed between plant species and locations, but not between any of the habitat treatments. This may have resulted from temporal separation of peak fruit availability between M. elliptica and C. monilifera, and differences in fruit morphology and disperser assemblages between Elaeocarpus spp. and C. monilifera. We also measured removal of C. monilifera fruits from stations in C. monilifera stands and from where C. monilifera had been eliminated with herbicide. In the herbicide-treated habitat, removal of C. monilifera fruits was reduced. This may assist control efforts and suggests that, to reduce seed dispersal, dense (core) populations should be targeted in control programs.

Local plant density can vary dramatically within populations and may modify both the quantity and effectiveness of pollinator activity and thus the reproductive output of plants. We tested the effects of local plant density and plant size on pollinator activity on the endangered plant Persoonia bargoensis in two remnant populations in Australia. Pollinator visitation was weakly but positively correlated with local plant density in both populations ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $R^{2}=0.25$ \end{document} , \do...

In plants, understanding the interactions between breeding systems and pollination ecology may enable us to predict the impacts of rarity. We used a comparative approach to test whether rarity is associated with reproductive biology in two closely-related species pairs. This system has been recently altered by changes in fire regimes and the introduction of European honeybees. More than 35% of flowers matured fruits in the common species after natural-pollination compared to

Summary Major bushfires in south-eastern Australia in the 2002–2003 bushfire season caused the loss of ten lives, substantial damage both to rural and urban property and to infrastructure and primary production systems, and had significant environmental impacts. The scale and impacts of the fires prompted the governments of the Australian Capital Territory and Victoria to establish inquiries into the bushfires in their jurisdictions, and the federal House of Representatives and Council of Australian Governments to establish inquiries with wider terms of reference. This paper reviews the outcomes of these inquiries in the context of the most wide-ranging, that of the Council of Australian Governments (COAG), which the authors conducted. The inquiries which followed the 2002–2003 bushfire season explored many of the common themes which had emerged from the preceding 13 inquiries into significant bushfire events in Australia since 1939. These include the importance of risk reduction, particularly through fue...

The genetic effects of population fragmentation cannot be interpreted without understanding the underlying pattern of genetic variation resulting from historic population processes. We used AFLP markers to determine genetic structure and distribution of genetic diversity among populations of an endangered Australian shrub Grevillea caleyi (Proteaceae). Populations that occurred historically on four ridges have new been fragmented to varying degrees, producing some large, relatively pristine populations and very small populations consisting of fewer than 10 adult plants. We found marked population genetic structure (65.9% of genetic variation was among populations) and a significant relationship between genetic and geographic distance (rm=0.564, P=0.004). However, only 14% of overall genetic differentiation was attributable to variation among ridges, compared with 52% among populations within ridges. Moreover, genetic diversity within samples of plants did not vary with either population size or degree of isolation. Thus, the present genetic structure of populations is probably almost entirely the product of historical events. Fine-scale structuring within populations prior to fragmentation may have been caused by limited seed and pollen dispersal, despite a complex suite of (mostly avian) pollinators, and a mixed mating system that allows a large amount of selfing. The combined effects of adult longevity and a soil-stored seed bank may have buffered the recently fragmented populations against the effects of dramatic reductions in numbers of adult plants.

In many fire-prone habitats around the world, natural fire regimes have shaped the evolution of the associated flora. Critical life history stages are often linked to fire in species that occur in these fire-prone habitats but many species are unstudied. We investigated seedling emergence patterns over time, after several fires in south-eastern Australia, for three obligate seeders in the Genus Leucopogon (Family Epacridaceae): L. setiger, L. esquamatus and L. exolasius. Fixed quadrats were monitored for 12 to 30 months for newly emerged seedlings, both after fire and in unburnt L. exolasius and L. esquamatus habitats. There was a flush of seedling emergence in the first year after fire for all three Leucopogon species, with smaller pulses recorded in subsequent years. Time elapsed between fire and the onset of emergence differed between fires, but not between Leucopogon species. Whatever the timing of the fire, seedling emergence was restricted to the late autumn and winter periods, coinciding with emergence in unburnt habitat. This contrasts with patterns of emergence previously reported for other taxa, and also in this study, where emergence of the Leucopogon species after fire was delayed compared with co-occurring species in other genera. Our results suggest that seasonal factors are important to the germination ecology of these species and that combinations of fire-related and seasonal factors are necessary to maximise germination. Rainfall has a non-seasonal pattern in the study region and seasonal emergence post-fire has not previously been recorded. The magnitude of delay to emergence of species with seasonal emergence patterns will be determined by the season of fire but not by a seasonal pattern of rainfall in the post-fire year. A shift of the peak fire season could increase this delay, possibly affecting plant population recovery.

Seed germination is dependent on the interaction between the dormancy state of a seed and the presence of favourable environmental conditions. Thus, the spectacular pulse of seedling recruitment in many Australian vegetation communities following disturbances such as fire can be attributed to changes in microsite conditions and/ or the dormancy-breaking effect of the disturbance on accumulated seed banks. Grevillea rivularis is a threatened species endemic to the area immediately above Carrington Falls in the NSW Southern Highlands. Most of the population is confined to the riparian vegetation zone in woodland and heath, and is therefore subject to periodic disturbance from fire and flood. For this species, a pulse of seedling recruitment has been recorded after fire, flood and mechanical soil disturbance. The aims of this study were to examine the density and vertical distribution of the soil-stored seed bank and to investigate the role of heat and scarification as cues for germination of fresh and soil-stored seed. There was a large seed bank under the canopies of established individuals (194 ± 73 seeds m -2 ) and most seeds were found in the 0-2 cm and leaf-litter layers of the soil profile. The germination response of soil-stored and fresh seed was examined using a hierarchical series of laboratory experiments. Seeds of G. rivularis showed marked dormancy polymorphism. Thirty-six percent of soil-stored seed germinated without treatment, whereas no untreated fresh seeds germinated. Scarification or heating caused significant germination of dormant soil-stored seed, but only scarification resulted in germination of dormant fresh seeds. These results highlight important differences in the dormancy state of soil-stored and fresh seed. Thus, being a riparian species in a fire-prone environment, the dormancy mechanisms in seeds of G. rivularis suit this species to disturbance by both fire and flood.

Recent habitat loss and fragmentation superimposed upon ancient patterns of population subdivision are likely to have produced low levels of neutral genetic diversity and marked genetic structure in many plant species. The genetic effects of habitat fragmentation may be most pronounced in species that form small populations, are fully self-compatible and have limited seed dispersal. However, long-lived seed banks, mobile pollinators and long adult lifespans may prevent or delay the accumulation of genetic effects. We studied a rare Australian shrub species, Grevillea macleayana (Proteaceae), that occurs in many small populations, is self-compatible and has restricted seed dispersal. However, it has a relatively long adult lifespan (c. 30 years), a long-lived seed bank that germinates after fire and is pollinated by birds that are numerous and highly mobile. These latter characteristics raise the possibility that populations in the past may have been effectively large and genetically homogeneous. Using six microsatellites, we found that G. macleayana may have relatively low within-population diversity (3.2-4.2 alleles/locus; Hexp = 0.420-0.530), significant population differentiation and moderate genetic structure (FST = 0.218) showing isolation by distance, consistent with historically low gene flow. The frequency distribution of allele sizes suggest that this geographical differentiation is being driven by mutation. We found a lack mutation-drift equilibrium in some populations that is indicative of population bottlenecks. Combined with evidence for large spatiotemporal variation of selfing rates, this suggests that fluctuating population sizes characterize the demography in this species, promoting genetic drift. We argue that natural patterns of pollen and seed dispersal, coupled with the patchy, fire-shaped distribution, may have restricted long-distance gene flow in the past.

Introductions of European honeybees have occurred globally, potentially affecting the natural pollination ecology of many plants. Introduced honeybees are now the most frequent visitors to the inflorescences of the self-compatible, bird-pollinated Australian shrub Grevillea macleayana and may therefore be expected to have altered the mating system. To examine the degree to which birds continue to play a role in determining the mating system of G. macleayana in this disturbed system, we compared outcrossing rates in open-pollinated inflorescences with inflorescences from which birds had been selectively excluded. Outcrossing rates were estimated from the microsatellite genotypes of over 100 seeds per population in three populations. Outcrossing rates ( t) in open-pollinated seeds were surprisingly low (0.062–0.225) and did not vary significantly among the three populations. Nevertheless, outcrossing was significantly lower when birds were excluded (data pooled from all populations). Two lines of evidence suggest that there are temporal fluctuations in outcrossing rate and hence that birds usually have a major effect on the mating system of G. macleayana. First, at one site, t was substantially lower than estimates from an earlier study (0.06 in 1995 cf. 0.85 in 1990). Second, fixation indices based on seeds were high in all populations ( >0.68), whereas values for the established plants ( parental generation) were much lower in two of the three populations (0.06–0.32). Our findings suggest that honeybee activity is so high that the contribution of birds to pollination in G. macleayana is sometimes relatively trivial. Resumen: La introduccion de abejas europeas ha ocurrido globalmente, lo que potencialmente afecta la ecologia de polinizacion natural de muchas plantas. Las abejas introducidas son los visitantes mas frecuentes de las inflorescencias del arbusto australiano auto-compatible, polinizado por aves Grevillea macleayana y puede esperarse que su sistema de apareamiento ha sido alterado. Para examinar el grado al que las aves continuan jugando un papel en la determinacion del sistema de apareamiento de G. macleayana en este sistema perturbado, comparamos las tasas de exogamia en inflorescencias de polinizacion abierta con inflorescencias de que se excluyeron selectivamente las aves. Las tasas de exogamia fueron estimadas de los genotipos microsatelite de mas de 100 semillas por poblacion en tres poblaciones. Las tasas de exogamia ( t) en semillas de polinizacion abierta fueron sorprendentemente bajas (0.062–0.225) y no variaron significativamente entre las tres poblaciones. Sin embargo, la exogamia fue significativamente menor cuando las aves fueron excluidas (considerando los datos de todas las poblaciones). Dos lineas de evidencia sugieren que hay fluctuaciones en la tasa de exogamia y en consecuencia que las aves generalmente tienen un mayor efecto en el sistema de apareamiento de G. macleayana. Primero, en un sitio t fue sustancialmente menor que en estimaciones de un estudio anterior (0.06 en 1995 cf. 0.85 en 1990). Segundo, los indices de fijacion basados en semillas fueron altos en todas las poblaciones ( >0.68), mientras que los valores para las plantas establecidas (generacion parental) fueron mucho menores en dos de las tres poblaciones (0.06–0.32). Nuestros resultados sugieren que la actividad de las abejas es quizas tan alto que la contribucion de las aves a la polinizacion de G. macleayana a veces es relativamente trivial.

Summary 1 Although the season of fire occurrence is known to affect recruitment to plant populations, it has received little attention. This study investigated the dynamics of the canopy-stored seed banks of two Australian obligate seeder shrubs, Petrophile sessilis and Hakea sericea (Proteaceae), with the objective of determining the changes in viable seed supply over a year. 2 The total number of germinable seeds in the canopy, each month for 12 months during 1996–97, was estimated from separate measures of (i) pre-dispersal predation of fruits; (ii) seed predation of insect parasitoids; (iii) viability of intact seeds; and (iv) loss of seed viability following experimental heating. 3 The two species had very different seed bank dynamics throughout the year. The seed store of P. sessilis appeared to be being replaced annually, as seeds in the older fruits rapidly lost germinability and new fruits matured to replace them. For H. sericea, the seed store appeared to be accumulating each year, because older fruits retained a high level of germinability. 4 The study indicates that no one fire season will maximize the germinable seed release after fire for all species. Management strategies should therefore include varied seasons of prescribed burning to avoid compositional change and a decrease in diversity that may result from a single-season approach.

Long-term canopy storage of seeds in fruits (bradyspory) varies among species and is thought to be related to the fire regime experienced by the plant community. This study sought to quantify intraspecific variation in bradyspory among nine populations of Banksia serrata (Proteaceae) on the south coast of New South Wales. Marked differences were found between populations, ranging from more than 30% of follicles open at two coastal sites, to less than 5% of follicles open at two inland heath sites. Low levels of bradyspory occurred particularly in coastal sites which also had Banksia integrifolia, a non-bradysporous species, present. In addition to spontaneous follicle opening without fire, fall of infructes-cences to the ground after breaking of branches was observed to be a major contributor to seed release. At three sites where fire had not occurred for many years, the amount of seedling establishment since the last fire corresponded well with levels of bradyspory; there were no inter-fire recruits at the site with the strongest bradyspory, while at the site with the weakest bradyspory there were numerous inter-fire plants, some with lignotubers large enough to be able to tolerate the next fire. It is argued that populations of B. serrata exhibit variable patterns of recruitment, depending on the site characteristics, ranging from complete dependence on fire for population maintenance to bet-hedging (spreading potential recruitment between fire events and inter-fire periods). Variations in populations and reproductive characteristics among sites make the application of demographic models to management decisions habitat-specific.

Road verge remnant native vegetation often provides a last refuge for many endangered plant species. However, the value of road verge populations is often questioned because their relatively small size and isolation is expected to reduce both their reproductive potential and their genotypic diversity. We assessed the fitness, genetic variability and links with other populations of small, disjunct and highly disturbed road verge populations of the rare Australian shrub Grevillea barklyana. We found that a set of three road verge populations produced significantly more inflorescences and seed than three nearby nonverge populations. Using three random amplified polymorphic DNA (RAPD) primers, we detected similar levels of genetic variability within and among road verge and nonverge populations. We detected a total of 23 polymorphic marker bands, which allowed us to assign a unique phenotype to each of 60 surveyed plants. AMOVA revealed that only 3.3 per cent of the total variability detected was attributable to variation between the two groups of populations. The majority (80 per cent) of variation occurred among individuals within populations, and 16.7 per cent occurred among populations within each population type. Surprisingly, this pattern of variation is similar to results reported for obligatorily outcrossing species. We conclude that our three road verge populations of G. barklyana have relatively great conservation value, as all were apparently as fecund and as genetically diverse as conspecific nonverge populations.

Mammals are frequent visitors to flowers in some Australian plant communities Nectar ib usually considered to be the food sought, because pollen is thought to be of low digestibility This study compared the abilities of four non-flying mammal species to extract the protoplasts from Banksia pollen grains and quantified the amount of pollen in the diets of the species over 16 months All four species were capable of extracting the protoplast from a large proporuon of the pollen grains that they ingested the mean percentage of empty Banksia pollen grains in the faeces ranged from 37% to 66% Banksia pollen was a major component in the faecal samples from two species, Cercartetus nanus and Petaurus breviceps, between March and October It occasionally compnsed a large proportion of Amechmus stuartti faeces but was rare in the faeces of Rattusfuscipes Other major components of faeces included invertebrates and plant matenal other than pollen and fungal spores As the four mammal species tested were all from separate families and all capable of extracting the protoplast from a large proportion of the pollen grains, it is concluded that the extraction of pollen protoplasts by mammals may be widespread and may require no special adaptations

We developed eight primer pairs for Banksia microsatellite markers (five using DNA from Banksia oblongifolia and three from Banksia robur) in order to study the processes of speciation within hybridizing B. oblongifolia, B. robur and Banksia paludosa complex. We genotyped four populations of B. oblongifolia and B. robur, and three of B. paludosa. Numbers of alleles ranged from 1 to 13 across the three species and observed average heterozygosities ranged from 0.000 to 0.833. At least four loci completely discriminated B. robur from B. oblongifolia and three discriminated B. paludosa from B. oblongifolia. Seven of these primers amplified DNA from at least two of three other local species.

Seedbanks are expected to buffer populations against disturbances, such as fire, that could alter the genetic composition of smaller, ephemeral adult populations. However, seedling genotypes may be influenced by the spatially heterogeneous nature of both the seedbank and the disturbance (for example, germination may vary with local disturbance) and also by selection acting on germination and post-germination performance. We used microsatellite-DNA surveys of seedlings emerging from the soil-stored seedbanks of Grevillea macleayana after wildfire to compare diversity and spatial structure in seedlings and adults, and through resampling of the seedling data set, to determine whether the resultant adult population reflected the effects of selection or random seedling mortality. The large post-fire seedling cohorts captured the full allelic diversity of the pre-fire adult population. However, we found a mismatch in the genotypic structure of adults and seedlings. Seedlings displayed larger heterozygous deficits than adults; however, over the ensuing 11 years, seedling heterozygosity eventually matched values for the pre-fire adults. Increasing heterozygosity among adults has generally been attributed to heterosis and/or reduction in Wahlund effects via self-thinning. Resampling of early post-fire seedlings to generate samples of equivalent size to survivors at 11 years showed that increases in heterozygosity must be driven by selection favouring outcrossed seed. This finding is important in an evolutionary context but also has implications for the restoration of natural or managed populations where a seedbank is a viable source of recruits.

Several features of the phenology and reproductive biology of members of the genus Banksia indicate that these plants either have a high level of mate choice or are obligate outcrossers, with many flowers being functionally male or sterile. These species produce many inflorescences with vast numbers of flowers, yet seed-set is typically very low. Most species studied appear to have at least limited self-compatibility and outcrossing rates close to one. Despite this, pollinators normally deposit a large amount of self-pollen on stigmas. In this study, we used experimental pollinations to test for evidence of preferential outcrossing within populations of Banksia spinulosa and Banksia ericifolia. Our allozyme analysis of progeny arrays indicates that the studied populations of both B. spinulosa from a prior study and B. ericifolia as determined for 27 plants in this study are highly outcrossed. Results from pollinations using applications of self- and cross-pollen and mixtures of the two indicated that, at ...

Fire-triggered release from seed dormancy is a characteristic of many Australian plant species. We investigated aspects of the seed-bank dynamics and dormancy characteristics in seeds of Grevillea barklyana, an understorey shrub of coastal sclerophyll vegetation in the Jervis Bay Region on the south coast of New South Wales. We used two soil core sizes to compare the number and distribution of stored seeds in soil cores taken from underneath and outside the limits of plant canopies at three study sites. Core size did not affect the estimate of seed density. No seeds were found outside the existing canopies. Even in under-canopy samples, seed numbers were small. Mean seed densities were estimated as 10.9, 14.1 and 4.3 seeds per ? ? ? for the three sites. A hierarchical series of laboratory experiments was used to test the germination response of both fresh and soil-stored seeds. Likewise, we attempted to simulate 'natural' disturbance conditions in a glasshouse experiment. Both laboratory and glasshouse experiments indicated polymorphism in germination behaviour. A constant proportion of seeds exhibited enforced dormancy, when moist at room temperature, while a smaller number of seeds showed either an induced dormancy or a non-seed-coat linked innate dormancy. The majority (75%) of seeds were innately dormant due to a hard seed-coat. This dormancy was broken when the seed-coat was damaged, for instance, by heat. The level of polymorphic germination behaviour will be dependent on the length of the inter-fire periods. We conclude that the expression of polymorphism within and between species across a range of environments and fire regimes is an important consideration for any further study attempting to assess the role of the seed-bank.

smoke, the sound of sirens, and constant news reports of evacuations, houses burned, houses saved, and national parks "destroyed." The news reports quickly spread across the globe, depicting the emergency as "a fire front stretching 60 km from the Blue Mountains to Wollongong and advancing towards Sydney." Although reports like these were exaggerated, the fires that ringed Sydney were as intense as any in memory, driven by hot, dry conditions and strong, changing winds. In 2 weeks in New South Wales, over 500,000 ha of native vegetation were burned, much of it in national parks and other conservation areas.

SUMMARY Natural regeneration of abandoned farmland in several areas within the catchments of the Sydney Water Board has been very slow. Several hypotheses have been put forward to explain the fact that natural reforestation has not occurred, even after up to 50 years of abandonment. This study examines regeneration in relation to substrate, soil types and soil chemistry. The abandoned farmlands occur on four main soil types: (i) eutrophic krasnozem, now occupied mainly by bracken fern (Pteridium esculentum) associated with young seedlings of Eucalyptus and Acacia; (ii) mesotro‐phic yellow earth, now occupied by blady grass (Imperata cylindrica), with few tree seedlings and scattered, dead Acacia trees; and (iii) mesotrophic alluvial soil, and (iv) oligotrophic lithosol, which both support stands of Acacia. The soil properties of the krasnozem and the yellow earth appear to be suitable for tree establishment and growth, and do not differ from similar soils in nearby areas currently under cultivation or sup...

The description of a digital ecosystem as a “loosely coupled, demand-driven, domain clustered, agent-based, self organised, collaborative environment where agents form temporary coalitions for a specific purpose or goal, and each is proactive and responsive for its own benefit” has intriguing similarities with the definition of an ecosystem in ecology. Perhaps the similarities suggest that a deeper understanding of ecology may benefit the further development of ICT, and any differences may therefore represent cautionary tales. In this presentation, I describe characteristics of some ecological systems at several levels - from species to ecosystem - and speculate on the potential of these examples to catalyse innovation in ICT.

†Background and Aims In perennial plants (especially post-fire resprouters), extant populations may reflect recruitment events in the distant past. This is true of hybrid zones formed by twoBanksia species of swamps and woodlands in south-eastern Australia,Banksia robur andB.oblongifolia. Both resprout after fire but recruitment is dependent on periodic fires. Although plants of intermediate morphology have also been identified as hybrids using allozyme markers, the extent of ongoing hybridization is unknown. This study investigates whether both microsatellite markers and morphological measurements can be used to distinguish between the two species and their hybrids. A recent recruitment event and microsatellite markers allow the frequency of ongoing hybridization to be estimated, and also the effects of environmental variation on the morphology of plants and seedlings to be tested. †Methods Variation at seven microsatellite loci was scored and seven leaf characteristics within putatively pure stands and mixed stands of both species were measured, revealing that the two species were genetically and morphologically distinct and that mixed stands also contained genetically and sometimes morphologically distinct hybrids. An opportunity created by wildfires was used to analyse the genetics and morphometrics of adults and seedlings from two hybrid zones. †Key Results Approximately 9 % of adults and 21 % of seedlings were identified as genetic hybrids in both hybrid zones. Within these sites, the genotype of mature plants correlated well with morphology, except for some hybrid plants that had parental morphology. However, seedling morphology was highly variable and insufficient to describe the composition of the hybrid zone in this cohort. Greater phenotypic plasticity was evident among seedlings growing within the hybrid zones than seedlings growing in pots. †Conclusions The hybrid zones are complex and the range of genotypes detected in seedlings reveals both continuing hybridization and introgression.

There are several possible explanations for the low fruit: flower ratios commonly observed in the Australian Proteaceae—some proximate and others ultimate. One of these, namely that some flowers on a plant are functionally male (andromonoecy), has recently received considerable attention. However, the term andromonoecy appears to have been misused in the pollination ecology literature. In this note, we clarify the use of the terms andromonoecy and androgyny, and suggest that they should be applied with care, only after it is clear that the flowers lack ovules or that they possess dysfunctional gynoecia. These terms should not be applied to post-fertilization events which result in ovule abortion. Further, we review the current evidence for andromonoecy or androgyny in the Proteaceae, especially the genus Banksia, and present the results of studies on two additional Banksia species, B. spinulosa and B. ericifolia. The evidence so far fails to provide support for widespread andromonoecy in this genus as an explanation for low fruit: flower ratios.

Vegetative resprouting, soil or canopy-stored seed banks, post-fire seed dispersal and germination are the major strategies by which plants regenerate after fires. Post-fire regeneration modes of plants are commonly based on the presence or absence of post-fire recruitment as well as the presence or absence of post-fire resprouting. High temperatures, smoke and ash are characteristics of fire and the post-fire environment. We hypothesized that heat, smoke, ash and pH will have differential effects on seed germination depending on species’ post-fire regeneration strategies: serotinous vs. nonserotinous (which may have soil seed banks) and resprouters vs. nonresprouters (which may be obligate seeders). Here we examined the effects of these factors on the germination of 27 common east Australian species. Most serotinous species supported our hypothesis by showing no effect or reduced germination in response to heat. However, contrary to our prediction, all nonserotinous nonresprouting species also showed no effect or reduced germination in response to heat. Smoke, contrary to our hypothesis, had a negative or no effect on all serotinous and nonresprouting species, but no clear directional effect on serotinous and resprouting species. Supporting our hypotheses, ash and high pH showed positive or nonsignificant effects on the germination of all serotinous resprouting species, and a negative or no effect on nonserotinous resprouting species. However, contrary to our prediction, it had a negative or no effect on the serotinous nonresprouting species and no clear effect on nonserotinous nonresprouting species. We also discovered large differences in germination responses between conspecific populations that varied in their degree of resprouting. Although our data confirmed several of our predictions, the overall conclusion is that the responses of seeds to heat, smoke, ash and pH are not tightly associated with post-fire regeneration functional types.

• Background and Aims Germination studies of species from fire-prone habitats are often focused on the role that fire plays in breaking dormancy. However, for some plant groups in these habitats, such as the genus Leucopogon (Ericaceae), dormancy of fresh seeds is not broken by fire cues. In the field, these same species display a flush of seedling emergence post-fire. Dormancy and germination mechanisms therefore appear complex and mostly unknown. This study aimed to identify these mechanisms by establishing dormancy class and testing the effects of a set of typical germination cues, including those directly related to fire and entirely independent of fire. • Methods To classify dormancy, we assessed seed permeability and embryo morphology, and conducted germination experiments at seasonal temperatures in incubators. To test the effects of fire cues on germination, factorial combinations of smoke, heat and dark treatments were applied. Ageing treatments, using burial and seasonal incubation, were also tested. Germination phenology was established. • Key Results Seeds were dormant at release and had underdeveloped embryos. Primary dormancy of the study species was classified as morphophysiological. Seasonal temperature changes overcame primary dormancy and controlled timing of germination. Fire cues did not break primary dormancy, but there was a trend for smoke to enhance germination once this dormancy was overcome. • Conclusions Despite the fact that fire is a predominant disturbance and that many species display a flush of emergence post-fire, seasonal temperatures broke the primary physiological dormancy of the study species. It is important to distinguish between fire being responsible for breaking dormancy and solely having a role in enhancing levels of post-fire germination for seeds in which dormancy has been overcome by other factors. Biogeographical evidence suggests that morphological and physiological factors, and therefore seasonal temperatures, are likely to be important in controlling the dormancy and patterns of post-fire germination of many species in fire-prone regions.

Dispersal in most plants is mediated by the movement of seeds and pollen, which move genes across the landscape differently. Grevillea macleayana is a rare, fire-dependent Australian shrub with large seeds lacking adaptations for dispersal; yet it produces inflorescences adapted to pollination by highly mobile vertebrates (eg birds). Interpreting fine-scale genetic structure in the light of these two processes is confounded by the recent imposition of anthropogenic disturbances with potentially contrasting genetic consequences: (1) the unusual foraging behaviour of exotic honeybees and 2. widespread disturbance of the soil-stored seedbank by road building and quarrying. To test for evidence of fine-scale genetic structure within G. macleayana populations and to test the prediction that such structure might be masked by disturbance of the seed bank, we sampled two sites in undisturbed habitat and compared their genetic structure with two sites that had been strongly affected by road building using a test for spatial autocorrelation of genotypes. High selfing levels inferred from genotypes at all four sites implies that pollen dispersal is limited. Consistent with this, we observed substantial spatial clustering of genes at 10 m or less in the two undisturbed populations and argue that this reflects the predicted effects of both high selfing levels and limited seed dispersal. In contrast, at the two sites disturbed by road building, spatial autocorrelation was weak. This suggests there has been mixing of the seed bank, counteracting the naturally low dispersal and elevated selfing due to honeybees. Pollination between near neighbours with reduced relatedness potentially has fitness consequences for G. macleayana in disturbed sites.