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Threatened species in rainforests may be vulnerable to climate change, because of their potentially narrow thermal tolerances, small population sizes, restricted distributions and limited dispersal. We investigated the relative influence of potential climate change on the population viability of Triunia robusta (Proteaceae), an endangered rainforest shrub endemic to southeast Queensland, Australia. A spatially explicit, stochastic population model with seven stage classes was developed and linked with the species distribution model (SDM) to explore a variety of hypothetical climate change simulations over a 90‐year period from 2010 to 2100: (1) constant population dynamics, (2) changes in habitat distributions as trend in carrying capacity and (3) changes in habitat distributions, precipitation and temperature regime as relative change in seedling survival and fecundity. The results revealed high vulnerability of small populations to local extinction regardless of geographical location or climatic stressors, while some larger populations located in the southern end of the species distribution range showed persistence in‐situ. Triunia robusta was found to be sensitive to reduced precipitation and increased temperature, limiting the species reproductive activities and seedling establishment and reducing the overall abundance consequently. Integration of population models and SDM allowed for the evaluation of multiple climatic stressors that may affect habitat distributions and population dynamics of T. robusta and ultimately suggest potential implications for future conservation and management planning with respect to climate change. [ABSTRACT FROM AUTHOR]

Background and Aims The prevailing view from the areocladogenesis of molecular phylogenies is that the iconic South African Cape Proteaceae (subfamily Proteoideae) arrived from Australia across the Indian Ocean during the Late Cretaceous (100–65 million years ago, Ma). Since fossil pollen indicates that the family probably arose in North-West Africa during the Early Cretaceous, an alternative view is that it migrated to the Cape from North-West-Central Africa. The plan therefore was to collate fossil pollen records throughout Africa to determine if they are consistent with an African (para-autochthonous) origin for the Cape Proteaceae, and to seek further support from other palaeo-disciplines. Methods We used palynology (identity, date and location of records), molecular phylogeny and chronogram preparation, biogeography of plate tectonics, and palaeo-atmospheric and ocean circulation models. Key Results Our collation of the rich assemblage of Proteaceae palynomorphs stretching back to 107 Ma (Triorites africaensis) in North-West Africa showed its progressive overland migration to the Cape by 75–65 Ma. No key palynomorphs recorded in Australia–Antarctica have morphological affinities with African fossils but specific clade assignment of the pre-Miocene records is not currently possible. The Cape Proteaceae encompass three molecular-based clades (tribes) whose most recent apparent ancestors are sisters to those in Australia. However, our chronogram shows that the major Adenanthos / Leucadendron -related clade, originating 54–34 Ma, would have 'arrived' too late as species with Proteaceae affinities were already present ~20 million years earlier. The Franklandia / Protea -related clade arose 118–81 Ma so its distinctive pollen should have been the foundation for the scores of palynomorphs recorded at 100–80 Ma, but it was not. Also, the prevailing winds and ocean currents trended away from South Africa rather than towards, as the 'out-of-Australia' hypothesis requires. Based on the evidence assembled here, we list three points favouring an Australian origin and nine against; four points favouring an Antarctic origin and seven against; and nine points favouring a North-West-Central African origin and three against. Conclusions We conclude that a gradual migration of the Proteaceae from North-West-Central Africa southeast→south→southwest to the Cape and its surroundings occurred via adaptation and speciation during the period 95–70 Ma. We caution that incorrect conclusions may be drawn from literal interpretations of molecular phylogenies that neglect the fossil record and do not recognize the possible confounding effects of selection under matched environments leading to parallel evolution and extinction of bona fide sister clades. [ABSTRACT FROM AUTHOR]

Background and aims: Proteaceae are a prominent plant family in south-western Australia. Most Proteaceae are 'calcifuge', occurring exclusively on old phosphorus (P)-impoverished acidic soils, with a few 'soil-indifferent' species also found on young P-richer calcareous soils. Calcium (Ca)-enhanced P toxicity explains the calcifuge habit of Proteaceae. However, previous research has so far been focused exclusively on the roles of Ca and P in determining Proteaceae distribution, and consequently there is little knowledge on how other soil-based strategies influence this distribution. We aimed to study the effects of young calcareous soils on four soil-grown Proteaceae and assess differences between calcifuge and soil-indifferent Proteaceae to better understand their natural distribution. Methods: Two calcifuge and two soil-indifferent Proteaceae from south-western Australia were grown in six contrasting soils, including young calcareous, and old acidic soils. Results: When grown in calcareous soils all species showed root growth inhibition, micronutrient deficiency, Ca-enhanced P toxicity, and negative impacts on physiology. Calcifuge species were more sensitive to calcareous soils than soil-indifferent ones, although this varied between genera. Soil-indifferent species tended to produce more cluster roots, release more carboxylates per root mass, and allocate less Ca to their leaves, compared with calcifuges; they also had smaller seeds and were less sensitive to Ca-enhanced P toxicity. Conclusion: We surmise that a combination of these traits allows soil-indifferent species to tolerate calcareous soils. This study provides insight into how Proteaceae respond to young calcareous soils and how this influences their distribution. [ABSTRACT FROM AUTHOR]

Background and aims: Hakea prostrata (Proteaceae) is a highly phosphorus-use-efficient plant native to southwest Australia. It maintains a high photosynthetic rate at low leaf phosphorus (P) and exhibits delayed leaf greening, a convergent adaptation that increases nutrient-use efficiency. This study aimed to provide broad physiological and gene expression profiles across leaf development, uncovering pathways leading from young leaves as nutrient sinks to mature leaves as low-nutrient, energy-transducing sources. Methods: To explore gene expression underlying delayed greening, we analysed a de novo transcriptome for H. prostrata across five stages of leaf development. Photosynthesis and respiration rates, and foliar pigment, P and nitrogen (N) concentrations were determined, including the division of P into five biochemical fractions. Key results: Transcripts encoding functions associated with leaf structure generally decreased in abundance across leaf development, concomitant with decreases in foliar concentrations of 85% for anthocyanins, 90% for P and 70% for N. The expression of genes associated with photosynthetic function increased during or after leaf expansion, in parallel with increases in photosynthetic pigments and activity, much later in leaf development than in species that do not have delayed greening. As leaves developed, transcript abundance for cytosolic and mitochondrial ribosomal proteins generally declined, whilst transcripts for chloroplast ribosomal proteins increased. Conclusions: There was a much longer temporal separation of leaf cell growth from chloroplast development in H. prostrata than is found in species that lack delayed greening. Transcriptome-guided analysis of leaf development in H. prostrata provided insight into delayed greening as a nutrient-saving strategy in severely phosphorus-impoverished landscapes. [ABSTRACT FROM AUTHOR]

Background and aims: In extremely low-phosphorus (P) environments, most Proteaceae exude carboxylates from cluster roots. These carboxylates mobilise inorganic P which leads to a relatively high leaf manganese concentration ([Mn]). However, we found that Adenanthos cygnorum (Proteaceae) in a low-P habitat did not invariably have a high leaf [Mn] in south-western Australia. We aimed to explore how A. cygnorum acquires P in severely P-impoverished habitats. Methods: We determined soil P concentrations and leaf [Mn] of A. cygnorum growing within 1 m and more than 10 m away from other large Proteaceae. We also grew plants in a glasshouse to determine its root carboxylate exudation and rhizosheath phosphatase activity. Results: Adenanthos cygnorum did not produce functional cluster roots. It depended on carboxylates released by a P-mobilising neighbour, Banksia attenuata (Proteaceae), to acquire P when growing in severely P-impoverished soil (< 8 mg P kg− 1 dry soil). In slightly less P-impoverished soil (> 11 mg P kg− 1 dry soil), phosphatases released by A. cygnorum hydrolysed sufficient organic P that was relatively mobile. Conclusion: The reliance on facilitation of P acquisition in A cygnorum depended strongly on location. We demonstrated the exudation of phosphatases, which mobilise inorganic P; this P was adequate for growth when there was sufficient organic P in soil. Facilitation of P acquisition by B. attenuata allowed A. cygnorum to extend its range into severely P-impoverished habitats where it cannot exist without facilitation. This knowledge provides a better understanding of the diversity of P-acquisition strategies in severely P-impoverished environments. [ABSTRACT FROM AUTHOR]

Background and Aims Soils in south-western Australia are severely phosphorus (P) impoverished, and plants in this region have evolved a variety of P-acquisition strategies. Phosphorus acquisition by Adenanthos cygnorum (Proteaceae) is facilitated by P-mobilizing neighbours which allows it to extend its range of habitats. However, we do not know if other Adenanthos species also exhibit a strategy based on facilitation for P acquisition in P-impoverished environments. Methods We collected leaf and soil samples of Adenanthos barbiger , A. cuneatus , A. meisneri, A. obovatus , A. sericeus and Adenanthos sp. Whicher Range (G.J. Keighery 9736) growing in their natural habitats at different locations within the severely P-limited megadiverse environment of south-western Australia. Hydroponic experiments were conducted to collect the carboxylates exuded by cluster roots. Pot experiments in soil were carried out to measure rhizosheath phosphatase activity. Key Results We found no evidence for facilitation of P uptake in any of the studied Adenanthos species. Like most Proteaceae, A. cuneatus , A. meisneri , A. obovatus , A. sericeus and Adenanthos sp. Whicher Range (G.J. Keighery 9736) expressed P-mining strategies, including the formation of cluster roots. Cluster roots of A. obovatus were less effective than those of the other four Adenanthos species. In contrast to what is known for most Proteaceae, we found no cluster roots for A. barbiger. This species probably expressed a post-fire P-acquisition strategy. All Adenanthos species used P highly efficiently for photosynthesis, like other Proteaceae in similar natural habitats. Conclusions Adenanthos is the first genus of Proteaceae found to express multiple P-acquisition strategies. The diversity of P-acquisition strategies in these Proteaceae, coupled with similarly diverse strategies in Fabaceae and Myrtaceae, demonstrates that caution is needed in making family- or genus-wide extrapolations about the strategies exhibited in severely P-impoverished megadiverse ecosystems. [ABSTRACT FROM AUTHOR]

Tingid classification has been problematic since the recognition of the family. The exaggerated ornamentation of many tingids has caused confusion in morphology-based phylogenies due to convergence. Also, some genera, like Ulonemia , lack exaggerated structures and their diagnoses rely on reduced morphology, making identification difficult. The relationship between these genera is of great interest, as several species of Ulonemia have recently become pests of Macadamia , and several of these genera are found on other Proteaceae. We used 16S, COI , 18S, and 28S to determine genus-level relationships of Ulonemia and other Australian Tingidae using maximum likelihood (ML) and Bayesian inference. We also analysed a morphological dataset using maximum parsimony. The parsimony analysis yielded numerous morphological homoplasies, and most deep clades lacked support. The ML and Bayesian analyses had strong support and returned a paraphyletic Ulonemia with three strongly supported clades. Two new genera, Cercotingis gen. nov. and Proteatingis gen. nov. are erected and Ulonemia redescribed to account for the observed phylogenies. Three new species of Cercotingis (C. croajingolong sp. nov. C. namadgi sp. nov. and C. tasmaniensis sp. nov.) and four new species of Proteatingis (Pr. astibosetes sp. nov. Pr. howardi sp. nov. Pr. minuta sp. nov. and Pr. xouthos sp. nov.) are described, with keys to species of Cercotingis and Proteatingis. [ABSTRACT FROM AUTHOR]

The Australian genus Isopogon (Proteaceae) consists of approximately 39 species, most of which occur in southwestern Australia, a region of considerable endemism and biodiversity. Unresolved taxonomic issues exist for two species complexes (nine suspected taxa) allied to I. spathulatus and I. polycephalus. There is uncertainty in how to delimit species in these two complexes due to unclear or overlapping morphological characters, although recognition of four phrase‐named taxa provide starting hypotheses for potential new taxa. We used a genomic approach (ddRAD) to generate SNPs for 146 samples from 32 populations across the two complexes to evaluate the genomic distinction of taxa and delimit species. We used an optimised ipyrad assembly of the sequenced libraries, followed by custom filtering of samples and SNPs for ordination, genetic structure, distance and concatenation and coalescent phylogenetic analyses. Population genetic and phylogenetic analyses consistently supported three geographically overlapping yet genomically distinct groups, two of which showed additional genomic divergence consistent with multiple distinct species. Existing morphological hypotheses were congruent with genomic groupings in some cases but discordant in others, where genomic admixture suggested existing taxa were conspecific. Evaluating morphological characters, geographic distribution and genomic distinction, we recognise five species and three subspecies from nine original taxa. We provide a key to species in the complexes and related taxa, updated descriptions for existing taxa, and describe two new species, I. elatus sp. nov. and I. pallidus sp. nov., and two new subspecies, I. spathulatus subsp. obovatus stat. nov. and I. spathulatus subsp. elongatus subsp. nov. [ABSTRACT FROM AUTHOR]

Banksia L.f., an iconic genus of the Proteaceae, is endemic to Australia, with its highest species richness and phylogenetic diversity (PD) in southwestern Western Australia. Analysis of the phylogenetic component of richness and endemism uncovered important patterns of Banksia evolutionary history that are not seen at the species level. We found that Banksia is significantly phylogenetically clustered in this region, likely due to recent evolutionary radiations. We also found significant concentrations of phylogenetic endemism in this region, both neoendemism (short, range‐restricted evolutionary branches) and paleoendemism (long, range‐restricted evolutionary branches). There is a striking northwest to southeast divide in phyloturnover in southwestern Western Australia. The majority of the variation in turnover patterns can be explained by environmental factors, with climate representing the largest covariate. This study adds to the growing body of evidence that indicates the importance of integrating phylogenetic and biodiversity data to inform conservation planning. [ABSTRACT FROM AUTHOR]

Well-preserved leaf fossils from the Middle Eocene Anglesea site in Victoria are assigned to a new species of Megahertzia (M. paleoamplexicaulis R.J.Carp. & Rozefelds), a genus of Proteaceae now represented by a single species, M. amplexicaulis A.S.George & B.Hyland, in the Wet Tropics rainforests of Queensland. Megahertzia -like cuticular remains also occur in the Eocene Mount Hotham assemblage of Victoria, and pollen closely conforming to Megahertzia (i.e. Proteacidites latrobensis W.K.Harris) occurs widely in Cenozoic sediments of Australia and in New Zealand. All these records add to other fossil evidence that many species of Australian rainforest Proteaceae are the last vestiges of formerly much more widespread lineages. The fossil leaves are near-identical in architecture and cuticular features to lobed leaves of M. amplexicaulis , including that they have small teeth, stomata in well-defined areoles, and fine cuticular striations. Moreover, where preserved, the leaf fossils show amplexicaul bases, a unique (apomorphic) trait of the extant species. The apparent absence at Anglesea of simple (unlobed) leaves in Megahertzia and two other taxa of fossil Proteaceae is discussed; this leaf type could have evolved convergently in response to forest canopy heat increase as Australia drifted towards the Equator. The World Heritage Queensland Wet Tropics support an amazing 15 endemic genera of the Gondwanan Proteaceae family, including Megahertzia from the Daintree rainforest. Megahertzia -like fossil leaves were first collected from the Anglesea coal mine (Victoria, 3000 km away!) over 30 years ago, but have never been described. New fossil studies show the sole living species of Megahertzia as the last vestige of a formerly much more widespread lineage, and underscore the imperative need for conserving Australia's unique rainforest biota. [ABSTRACT FROM AUTHOR]

Flower diseases threaten macadamia production, but there is a limited understanding of their aetiology. This study was undertaken to establish the ecology of the causal agents in commercial orchards in Australia. Raceme samples at different developmental stages were collected from 42 commercial macadamia orchards during the 2018–2020 flowering seasons. Morphological and molecular phylogenetic analyses of the isolates obtained from the samples with symptoms revealed that 16 fungal species, including two Botrytis spp., six Cladosporium spp., six Neopestalotiopsis spp. and two Pestalotiopsis spp., were associated with the flower blights. Twelve of the fungal species were identified as new records in macadamia. A comparison of the fungal genera showed that Neopestalotiopsis spp. (48%) and Cladosporium spp. (47%) were the most prevalent in the majority of macadamia production regions and were obtained from all four raceme developmental stages. The genus Botrytis was more commonly distributed (16%) in the production areas where humidity was high and was mostly isolated from the mature developmental raceme stages. Based on in planta infection assays under field conditions, the fungal pathogens varied in aggressiveness on macadamia racemes, with B. cinerea, B. macadamiae, C. cladosporioides, C. devikae, N. drenthii, N. macadamiae, N. maddoxii, N. vheenae, P. macadamiae and P. telopeae as the most aggressive and C. angulosum and C. proteacearum as the least aggressive. This study improves our understanding of the aetiology and distribution of the causal agents of flower blight complex in macadamia. [ABSTRACT FROM AUTHOR]

The frequency and intensity of drought events are predicted to increase because of climate change, threatening biodiversity and terrestrial ecosystems in many parts of the world. Drought has already led to declines in functionally important tree species, which are documented in dieback events, shifts in species distributions, local extinctions, and compromised ecosystem function. Understanding whether tree species possess the capacity to adapt to future drought conditions is a major conservation challenge. In this study, we assess the capacity of a functionally important plant species from south-eastern Australia (Banksia marginata, Proteaceae) to adapt to water-limited environments. A water-manipulated common garden experiment was used to test for phenotypic plasticity and genetic adaptation in seedlings sourced from seven provenances of contrasting climate-origins (wet and dry). We found evidence of local adaptation relating to plant growth investment strategies with populations from drier climate-origins showing greater growth in well-watered conditions. The results also revealed that environment drives variation in physiological (stomatal conductance, predawn and midday water potential) and structural traits (wood density, leaf dry matter content). Finally, these results indicate that traits are coordinated to optimize conservation of water under water-limited conditions and that trait coordination (phenotypic integration) does not constrain phenotypic plasticity. Overall, this study provides evidence for adaptive capacity relating to drought conditions in B. marginata, and a basis for predicting the response to climate change in this functionally important plant species. [ABSTRACT FROM AUTHOR]

Background and aims: Proteaceae species strongly acidify their rhizosphere to increase soil phosphorus (P) availability, which also inadvertently increases the availability of other elements, such as manganese and rare earth elements (REE). This study aimed to investigate REE (hyper) accumulation in the Proteaceae genus Helicia from Queensland, Australia, from a systematic assessment of REE concentrations in herbarium specimens and verification with field collected samples. Methods: Herbarium X-ray fluorescence (XRF) scanning (using yttrium as a proxy for REEs) was undertaken on selected Helicia species (Proteaceae) at the Queensland Herbarium, followed by Inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis and field collection of H. glabriflora samples to confirm the XRF findings. Results: The herbarium XRF analysis revealed highly anomalous REE concentrations in some Helicia species, reaching ~ 1300 µg Y g-1 in H. australasica and H. glabriflora. The ICP-AES analysis of the herbarium specimens revealed total REE concentrations (REE) of up to 2300 µg g-1 in H. australasica and H. glabriflora, with relatively higher light REEs (~ 70%) and yttrium (~ 20%) concentrations, compared to heavy REEs (~ 10%). The field collected H. glabriflora material had relatively higher total REE concentrations in the mature leaves (~ 850 µg REE g-1) and stems (~ 675 µg REE g-1), compared to young leaves (~ 130 µg REE g-1), roots (~ 220 µg REE g-1) and soil (~ 90 µg REE g-1). Conclusion: The discovery of REE (hyper)accumulation in these Helicia species suggests that the Proteaceae family may host several other REE hyperaccumulators that are hitherto undiscovered. This calls for systematic assessment of the Proteaceae using the same approach as used in this study. The findings have potential implications for (i) discovery of REE hyperaccumulator plants, (ii) investigation of REE uptake and accumulation in plants and (iii) biogeochemical exploration of buried REE ore deposits. [ABSTRACT FROM AUTHOR]

Phosphite has been sprayed on threatened natural plant communities in southwestern Australia for the past 25 years to mitigate the impact of the globally widespread plant pathogen, Phytophthora cinnamomi. Of concern is that this may result in an increase in phosphorus concentrations in naturally nutrient deficient soils, causing the loss of plant species that are sensitive to increased phosphorus levels. The impact of aerial spraying phosphite on soil and Proteaceae species richness and abundance was measured at three sites within the Southeast Coastal Province of Western Australia. Healthy and diseased vegetation which had been sprayed with phosphite for 14–26 years was compared with nonsprayed healthy and diseased vegetation. Contrary to expectations, there was no evidence that spraying is doing harm to Proteaceae species at the three sites studied. Healthy‐nonsprayed and Healthy‐sprayed areas had generally similar levels of soil total P, and this was associated with similar values for Proteaceae species richness and abundance in these areas. Phosphite spraying of diseased vegetation benefited Proteaceae plant diversity and abundance by preventing the disappearance of some species. Given these results, it was recommended that phosphite spraying be continued as a management action for controlling Phytophthora cinnamomi while research into alternative solutions continues. [ABSTRACT FROM AUTHOR]

Narrowly endemic species are particularly vulnerable to catastrophic events. Compared to widespread species, they may also be less capable of adapting to shifts in environmental pressures as a result of specialisation on a narrow range of local condition and limited ability to disperse. However, life-history traits, such as preferential outcrossing and high fecundity can maintain genetic diversity and evolutionary potential, and boost species resilience. The endangered Grevillea bedggoodiana (Enfield Grevillea) is an understorey shrub restricted to an area of ca. 150 km2 in south-eastern Australia with a legacy of large-scale anthropogenic disturbance. Prior to this study little was known about its biology and population structure. Here, its breeding system was assessed through a controlled pollination experiment at one of its central populations, and eight populations were sampled for genetic analysis with microsatellite markers. The species was found to be preferentially outcrossing, with no evidence of pollination limitation. In most populations, allelic richness, observed heterozygosity and gene diversity were high (Ar: 3.8–6.3; Ho: 0.45–0.65, He: 0.60 − 0.75). However, the inbreeding coefficients were significant in at least four populations, ranging from Fi -0.061 to 0.259 despite high outcrossing rates. Estimated reproductive rates varied among sampled populations but were independent of gene diversity and inbreeding. Despite its small geographic range, the species' populations showed moderate differentiation (AMOVA: FST = 0.123), which was largely attributable to isolation by distance. We interpret these results as suggesting that G. bedggoodiana is reproductively healthy and has maintained high levels of genetic diversity despite recent disturbance. [ABSTRACT FROM AUTHOR]

Translocation is commonly used in the conservation of threatened species to help mitigate the risk of local extinctions. However, translocations are often limited by knowledge of the species ecological requirements that promote persistence in the landscape. Small translocation trials with a strong experimental design can help to address species knowledge gaps and identify effective strategies for the successful establishment of a threatened species prior to implementing full‐scale planting regimes. In this study, we experimentally translocated 128 plants of the endangered Persoonia hirsuta (Proteaceae) at a dry sclerophyll mining offset in New South Wales (NSW), Australia, and investigated the effects of propagation type (seeds and vegetative cuttings), plant guards, and mulching on short‐term plant growth and survival. Transplants were impacted by herbivory and unprecedented extreme temperatures over summer 2019–2020 with 25 of the 128 plants surviving after 20 months of monitoring. Among the surviving individuals, all but one were seed propagated and 72% of survivors were protected by a plant guard. Short‐term survival and establishment of P. hirsuta translocants was increased by producing plants from seeds, and the use of plant guards with localized mulch. We also identified significantly greater root volume, projected area, and diameter for seedlings than cuttings grown plants. Our study successfully identified several key factors that should be considered for the ongoing management of P. hirsuta and vindicates the importance of small experimental trials when planning threatened plant translocations. [ABSTRACT FROM AUTHOR]

Climate change and land management decisions have considerably altered fire regimes globally resulting in increased risks of extreme fire seasons. Fire intensity is one characteristic of fire regime which is projected to increase. However, the magnitude and impact of intense fires on plant habitat and life history characteristics (such as the soil environment or seedling recruitment) remain unclear for many species. The widespread 2019–2020 Black Summer fires across Eastern Australia provided the opportunity to examine the impact of these fires on the short‐term regeneration of the Endangered Persoonia hirsuta (Proteaceae), an obligate seeding (reliant on regeneration from seed following fire) shrub presently threatened by population decline and dieback (plant death from branch and root tips backwards) of an unknown cause. In this study, we used a combination of metrics to estimate fire severity in the field at 22 plots across three fire‐affected populations which we used as a proxy to understand the relative impacts of fire intensity on P. hirsuta regeneration post‐fire. We also recorded the recruitment, growth, dieback and mortality of P. hirsuta seedlings at these plots over 21 months following the fires and examined whether the post‐fire soil environment (carbon, nitrogen and phosphorus) was related to fire severity and seedling responses. Seedling recruitment and growth were variable across sites and showed no relationship to fire severity. However, seedling dieback and mortality were significantly higher among plots exposed to high severity fires. Additionally, characteristics of the post‐fire soil environment varied by fire severity and explained variation in seedling recruitment, growth and dieback. Our work provides important evidence that already vulnerable populations of P. hirsuta may be further threatened by increasing fire severity, highlighting the importance of understanding the effects of fire on habitat and life history characteristics for threatened plants. [ABSTRACT FROM AUTHOR]

Telopea speciosissima, the New South Wales waratah, is an Australian endemic woody shrub in the family Proteaceae. Waratahs have great potential as a model clade to better understand processes of speciation, introgression and adaptation, and are significant from a horticultural perspective. Here, we report the first chromosome‐level genome for T. speciosissima. Combining Oxford Nanopore long‐reads, 10x Genomics Chromium linked‐reads and Hi‐C data, the assembly spans 823 Mb (scaffold N50 of 69.0 Mb) with 97.8% of Embryophyta BUSCOs "Complete". We present a new method in Diploidocus (https://github.com/slimsuite/diploidocus) for classifying, curating and QC‐filtering scaffolds, which combines read depths, k‐mer frequencies and BUSCO predictions. We also present a new tool, DepthSizer (https://github.com/slimsuite/depthsizer), for genome size estimation from the read depth of single‐copy orthologues and estimate the genome size to be approximately 900 Mb. The largest 11 scaffolds contained 94.1% of the assembly, conforming to the expected number of chromosomes (2n = 22). Genome annotation predicted 40,158 protein‐coding genes, 351 rRNAs and 728 tRNAs. We investigated CYCLOIDEA (CYC) genes, which have a role in determination of floral symmetry, and confirm the presence of two copies in the genome. Read depth analysis of 180 "Duplicated" BUSCO genes using a new tool, DepthKopy (https://github.com/slimsuite/depthkopy), suggests almost all are real duplications, increasing confidence in the annotation and highlighting a possible need to revise the BUSCO set for this lineage. The chromosome‐level T. speciosissima reference genome (Tspe_v1) provides an important new genomic resource of Proteaceae to support the conservation of flora in Australia and further afield. [ABSTRACT FROM AUTHOR]

The calcifuge habit of plants is commonly explained in terms of high soil pH and its effects on nutrient availability, particularly that of phosphorus (P). However, most Proteaceae that occur on nutrient‐impoverished soils in south‐western Australia are calcifuge, despite their ability to produce cluster‐roots, which effectively mobilize soil P and micronutrients. We hypothesize that the mechanism explaining the calcifuge habit in Proteaceae is their sensitivity to P and calcium (Ca), and that soil‐indifferent species are less sensitive to the interaction of these nutrients. In this study, we analyzed growth, gas‐exchange rate, and chlorophyll fluorescence of two soil‐indifferent and four calcifuge Hakea and Banksia (Proteaceae) species from south‐western Australia, across a range of P and Ca concentrations in hydroponic solution. We observed Ca‐enhanced P toxicity in all analyzed species, but to different extents depending on distribution type and genus. Increasing P supply enhanced plant growth, leaf biomass, and photosynthetic rates of soil‐indifferent species in a pattern largely independent of Ca supply. In contrast, positive physiological responses to increasing [P] in calcifuges were either absent or limited to low Ca supply, indicating that calcifuges were far more sensitive to Ca‐enhanced P toxicity. In calcifuge Hakeas, we attributed this to higher leaf [P], and in calcifuge Banksias to lower leaf zinc concentration. These differences help to explain these species' contrasting sensitivity to Ca‐enhanced P toxicity and account for the exclusion of most Proteaceae from calcareous habitats. We surmise that Ca‐enhanced P toxicity is a major factor explaining the calcifuge habit of Proteaceae, and, possibly, other P‐sensitive plants. [ABSTRACT FROM AUTHOR]

OCBIL theory provides a basis for understanding of the evolution and ecology of biota on old, climatically buffered, infertile landscapes (OCBILs) worldwide. Here, we test a genetic hypothesis presented in OCBIL theory that predicts highly differentiated intraspecific population systems on OCBILs vs. more limited differentiation on young, often disturbed, fertile landscapes (YODFELs). We examined patterns of genomic and morphological divergence in Banksia seminuda across OCBILs and YODFELs in south-western Australia. We also used these data to determine whether these OCBIL and YODFEL populations represent distinct subspecific lineages, a point of previous contention among taxonomists. As hypothesized, genomic analyses based on 3466 SNP loci revealed strong structuring within B. seminuda , with high differentiation across narrow geographic scales among OCBIL populations vs. lower differentiation across much larger geographic scales among YODFEL populations. In addition, genomic and morphological divergence was found between OCBIL and YODFEL populations, providing comprehensive quantitative evidence for two subspecies. These findings have taxonomic implications for the species and provide support for OCBIL theory and its insights into the evolution, ecology and conservation of biota on ancient landscapes. [ABSTRACT FROM AUTHOR]

Processes driving the divergence of floral traits may be integral to the extraordinary richness of flowering plants and the assembly of diverse plant communities. Several models of pollinator‐mediated floral evolution have been proposed; floral divergence may (i) be directly involved in driving speciation or may occur after speciation driven by (ii) drift or local adaptation in allopatry or (iii) negative interactions between species in sympatry. Here, we generate predictions for patterns of trait divergence and community assembly expected under these three models, and test these predictions in Hakea (Proteaceae), a diverse genus in the Southwest Australian biodiversity hotspot. We quantified functional richness for two key floral traits (pistil length and flower color), as well as phylogenetic distances between species, across ecological communities, and compared these to patterns generated from null models of community assembly. We also estimated the statistical relationship between rates of trait evolution and lineage diversification across the phylogeny. Patterns of community assembly suggest that flower color, but not floral phenology or morphology, or phylogenetic relatedness, is more divergent in communities than expected. Rates of lineage diversification and flower color evolution were negatively correlated across the phylogeny and rates of flower colour evolution were positively related to branching times. These results support a role for diversity‐dependent species interactions driving floral divergence during the Hakea radiation, contributing to the development of the extraordinary species richness of southwest Australia. [ABSTRACT FROM AUTHOR]

Scope: Proteaceae are an ecologically distinctive family, with largest radiations in the sclerophyll vegetation types of Australia and South Africa. This brief paper comments on Hayes et al. (2021), who have mapped leaf phosphorus concentration on to the phylogenetic tree for the family. Conclusions: Considered across all seed plants worldwide, Proteaceae contribute most of the lowest leaf nitrogen (N) and phosphorus (P) concentrations known. Hayes et al. concluded that they have used low-phosphorus strategy from their origins ca. 100 My ago. Occasional excursions into higher leaf P have been relatively recent and have not produced many species. The family as a whole is an instance of phylogenetic niche conservatism. The conservatism arises not from trait inertia but from the intensity of competition in continental vegetation, giving Proteaceae competitive advantage within distinct niches and inhibiting them from radiating into other ways of life. When a distinct niche is concentrated into a single clade in this way, quantitative methods that test for replicate patterns across multiple clades will not detect strong signal. However, niche-conservative clades make important and distinctive contributions to the world's ecology. [ABSTRACT FROM AUTHOR]

Aims: Non-mycorrhizal species such as Banksia (Proteaceae) that depend on root exudates to acquire phosphorus (P) are prominent in south-western Australia, a biodiversity hotspot on severely P-impoverished soils. We investigated the consequences of an exudate-releasing P-mobilising strategy related to control of iron (Fe) acquisition in two Banksia species, B. attenuata R.Br. and B. laricina C. Gardner, that differ greatly in their geographical distribution and rarity. Methods: We undertook solution culture experiments to measure root-mediated Fe reduction (FeR) in non-cluster and cluster roots at four stages of cluster-root development, and whole root systems for plants grown at 2 to 300 μM Fe (as Fe-EDTA). As a positive control, we used Pisum sativum (cv. Dunn) to validate the FeR assay. Results: Unlike typical Strategy I species, both Banksia species showed no significant variation in FeR, for either cluster or non-cluster roots, when grown at a wide range of Fe supply. For roots of different developmental stages, we measured a range for B. attenuata cluster roots of 0.13 ± 0.03 to 1.29 ± 0.14 μmol Fe3+ reduced g−1 FW h−1 and 0.56 ± 0.11 to 1.10 ± 0.24 μmol Fe3+ reduced g−1 FW h−1 in non-cluster roots. Similarly, for B. laricina cluster-roots, FeR ranged from 0.22 ± 0.07 to 1.21 ± 0.37 μmol Fe3+ reduced g−1 FW h−1, and in non-cluster roots from 0.56 ± 0.11 to 0.71 ± 0.08 μmol Fe3+ reduced g−1 FW h−1. We also observed only minor differences for whole-root system FeR, and even though B. attenuata showed signs of leaf Fe deficiency in the 2 μM Fe treatment, its FeR was the lowest of both species across all treatments at 0.079 ± 0.009 μmol Fe3+ reduced g−1 FW h−1, compared with the fastest rate of 0.20 ± 0.014 μmol Fe3+ reduced g−1 FW h−1 for B. laricina in the 28 μM Fe treatment. Taking plants through a pulse from low to high Fe, then back to low Fe supply did not elucidate any significant response in FeR. Conclusions: Although Fe acquisition is tightly controlled in the investigated Banksia species, such control is not based on regulation of FeR, which challenges the model that is commonly accepted for Strategy I species. [ABSTRACT FROM AUTHOR]

Very few of the >650 Proteaceae species in south-western Australia cope with the high calcium (Ca) levels in young, calcareous soils (soil indifferent); most are Ca sensitive and occur on nutrient-impoverished, acidic soils (calcifuge). We assessed possible control points for Ca transport across roots of two soil-indifferent (Hakea prostrata and Banksia prionotes) and two calcifuge (H. incrassata and B. menziesii) Proteaceae. Using quantitative X-ray microanalysis, we investigated cell-specific elemental Ca concentrations at two positions behind the apex in relation to development of apoplastic barriers in roots of plants grown in nutrient solution with low or high Ca supply. In H. prostrata , Ca accumulated in outer cortical cells at 20 mm behind the apex, but [Ca] was low in other cell types. In H. incrassata , [Ca] was low in all cells. Accumulation of Ca in roots of H. prostrata corresponded to development of apoplastic barriers in the endodermis. We found similar [Ca] profiles in roots and similar [Ca] in leaves of two contrasting Banksia species. Soil-indifferent Hakea and Banksia species show different strategies to inhabit calcareous soils: H. prostrata intercepts Ca in roots, reducing transport to shoots, whereas B. prionotes allocates Ca to specific leaf cells. [ABSTRACT FROM AUTHOR]

Hundreds of Proteaceae species in Australia and South Africa typically grow on phosphorus (P)‐impoverished soils, exhibiting a carboxylate‐releasing P‐mobilizing strategy. In the Southwest Australian Biodiversity Hotspot, two Xylomelum (Proteaceae) species are widely distributed, but restricted within that distribution.We grew Xylomelum occidentale in hydroponics at 1 μM P. Leaves, seeds, rhizosheath and bulk soil were collected in natural habitats.Xylomelum occidentale did not produce functional cluster roots and occupied soils that are somewhat less P‐impoverished than those in typical Proteaceae habitats in the region. Based on measurements of foliar manganese concentrations (a proxy for rhizosphere carboxylate concentrations) and P fractions in bulk and rhizosheath soil, we conclude that X. occidentale accesses organic P, without releasing carboxylates. Solution 31P‐NMR spectroscopy revealed which organic P forms X. occidentale accessed.Xylomelum occidentale uses a strategy that differs fundamentally from that typical in Proteaceae, accessing soil organic P without carboxylates. We surmise that this novel strategy is likely expressed also in co‐occurring non‐Proteaceae that lack a carboxylate‐exuding strategy. These co‐occurring species are unlikely to benefit from mycorrhizal associations, because plant‐available soil P concentrations are too low.Synthesis. Our findings show the first field evidence of effectively utilizing soil organic P by X. occidentale without carboxylate exudation and explain their relatively restricted distribution in an old P‐impoverished landscape, contributing to a better understanding of how diverse P‐acquisition strategies coexist in a megadiverse ecosystem. [ABSTRACT FROM AUTHOR]

In Australia, Phytophthora cinnamomi is the only species reported as the causal agent of stem canker and root rot in macadamia. In other countries, five Phytophthora species have been reported to cause diseases in macadamia, which led us to question if more than one Phytophthora species is responsible for poor tree health in macadamia orchards in Australia. To investigate this, samples were collected from the rhizosphere, stem, and root tissues of trees with and without symptoms, nurseries, and water sources from 70 commercial macadamia orchards in Australia. Phytophthora isolates were identified based on morphological characteristics and DNA sequencing. P. cinnamomi was the most predominant and widely distributed species, and was obtained from the different types of samples including symptomless root tissues. In addition to P. cinnamomi, only P. multivora was isolated from diseased tissue (stem canker) samples. Six other Phytophthora species were obtained from the rhizosphere samples: P. pseudocryptogea, P. citrophthora, P. nicotianae, P. gondwanense, P. sojae, and a new Phytophthora taxon. Only P. cinnamomi was obtained from macadamia nursery samples, while five Phytophthora species were obtained from water sources. Of the heterothallic Phytophthora species, mating type A2 isolates were dominant in P. cinnamomi isolates, whereas only mating type A1 isolates were obtained for P. nicotianae, P. pseudocryptogea, and P. citrophthora. Pathogenicity assays revealed that P. cinnamomi and P. multivora caused significantly larger stem and leaf lesions than P. citrophthora, P. nicotianae, and P. pseudocryptogea. Phytophthora sp. and P. sojae were nonpathogenic towards leaves and stems. [ABSTRACT FROM AUTHOR]

Background and Aims Ant–plant associations are widely diverse and distributed throughout the world, leading to antagonistic and/or mutualistic interactions. Ant pollination is a rare mutualistic association and reports of ants as effective pollinators are limited to a few studies. Conospermum (Proteaceae) is an insect-pollinated genus well represented in the south-western Australia biodiversity hotspot, and here we aimed to evaluate the role of ants as pollinators of C. undulatum. Methods Pollen germination after contact with several species of ants and bees was tested for C. undulatum and five co-flowering species for comparison. We then sampled the pollen load of floral visitors of C. undulatum to assess whether ants carried a pollen load sufficient to enable pollination. Lastly, we performed exclusion treatments to assess the relative effect of flying- and non-flying-invertebrate floral visitors on the reproduction of C. undulatum. For this, we measured the seed set under different conditions: ants exclusion, flying-insects exclusion and control. Key Results Pollen of C. undulatum , along with the other Conospermum species, had a germination rate after contact with ants of ~80 % which did not differ from the effect of bees; in contrast, the other plant species tested showed a drop in the germination rate to ~10 % following ant treatments. Although ants were generalist visitors, they carried a pollen load with 68–86 % of suitable grains. Moreover, ants significantly contributed to the seed set of C. undulatum. Conclusions Our study highlights the complexity of ant–flower interactions and suggests that generalizations neglecting the importance of ants as pollinators cannot be made. Conospermum undulatum has evolved pollen with resistance to the negative effect of ant secretions on pollen grains, with ants providing effective pollination services to this threatened species. [ABSTRACT FROM AUTHOR]

Australian macadamia production is threatened by a disorder known as abnormal vertical growth (AVG), for which the etiology is unknown. AVG is characterized by vigorous upright growth and reduced lateral branching, flowering, and nut set that results in over 70% yield loss annually. Six commercial macadamia orchards were surveyed in 2012 and again in 2018 to examine spatiotemporal dynamics of the epidemic. Data were subjected to point-pattern and geostatistical analyses. AVG incidence in all orchards showed a better fit to the beta-binomial distribution than the binomial distribution. AVG incidence in the different orchards varied between 5 and 47% in 2012, and 13 and 55% in 2018 and the rate of spread was slow, averaging at about 2% increase in disease incidence per annum. Spatial patterns of AVG were highly aggregated on both survey years and spread was mainly between neighboring trees in a row or trees that were opposite to each other in different rows. Semivariograms showed large range values (approximately 15 to 120), indicating aggregation of AVG-affected trees beyond quadrat levels. Furthermore, clusters of disease were mainly at the edge of the orchard on the first survey date and the disease progressed toward the center of the orchard over time. It is concluded that AVG is caused by an infectious agent, and based on patterns of spread, we hypothesize that spread is facilitated by root grafting or root-to-root contact. Furthermore, a vascular-limited pathogen could be involved that modulates plant hormone production. [ABSTRACT FROM AUTHOR]

Land clearing of habitat into smaller, isolated remnants is a major driver of plant and animal extinctions globally. In southeastern Australia, once widespread temperate savannas have been subjected to extensive land clearing since European settlement. Some small fragments have persisted, but declines in the dominant trees have been reported, with anecdotal observations of widespread recruitment bottlenecks and seed set failure. To test the hypothesis that populations of Banksia marginata are experiencing widespread recruitment bottlenecks, we examined tree size-class distribution and production of infructescences (cones) of 15 populations on the western plains of Victoria, Australia. We found no evidence of widespread recruitment bottlenecks or a failure to set seeds; most populations were recruiting, though we did find evidence of declining recruitment with population size, suggesting evidence of an Allee effect. The proportion of trees without cones varied between populations; three populations had large numbers of trees (> 40%) lacking mature fertile cones. Managers should focus on minimising threats to seedling survival and augment populations below 100 individuals to improve recruitment and maintain stand persistence in the landscape. [ABSTRACT FROM AUTHOR]

Phomopsis husk rot (PHR) in macadamia is a disease of economic importance in major commercial production areas in Australia and South Africa. Effective control of PHR is hindered by limited knowledge about its aetiology and epidemiology. The diversity and pathogenicity of more than 50 isolates of Diaporthe associated with PHR in macadamia orchards in Australia and South Africa was assessed. Multilocus phylogenetic analyses of DNA sequences of the ITS, tef1α, and tub2 gene loci revealed four novel clades that are described as Diaporthe australiana sp. nov., D. drenthii sp. nov., D. macadamiae sp. nov., and D. searlei sp. nov. Pathogenicity tests with representative isolates found that all four species caused PHR of varying severity between and within species, as well as between the two macadamia cultivars HAES 344 and HAES 816. The Australian species, D. australiana, was the most aggressive species compared with the three South African species. This study improves our understanding of the aetiology of PHR in macadamia and paves the way for more effective disease management. [ABSTRACT FROM AUTHOR]

Aim: Seasonal germination is critical in synchronizing seedling emergence with optimal conditions for survival but will be disrupted by climate change. Understanding how germination of threatened species with complex dormancy patterns will be affected by climate change is a priority for their management. By exploring the effects of temperature on germination for six Persoonia species ranging in rareness, this study aims to improve ex situ plant production and better understand the probable impacts of climate change on persistence of local populations. Location: South‐eastern Australia. Methods: The role of temperature on seed dormancy was explored using generalized additive models to predict germination probabilities for six Persoonia species ranging in rarity. Embryos were exposed to 24‐hr cycles of alternating 12‐hr warmer/light and 12‐hr cooler/dark combinations of temperatures between 8°C and 45°C. Optimal temperature conditions for germination were determined, and spatiotemporal changes in germination probability were predicted in response to expected temperatures under future climate change scenarios. Results: Unique germination niches representing complex responses across diurnal regimes were identified for each species. Germination probability was predicted to decline in four species in response to warmer day or night temperatures and in two species in response to cooler day or night temperatures. Across bioregions, areas of likely germination largely aligned with species‐specific temperature sensitivity, with suitable germination niche declining in four species, one staying roughly the same and one increasing in physical range under predicted climate warming. Main conclusions: In response to increased temperatures associated with climate change, germination probability varied from current rates. These changes were quantified both spatially and temporally and highlight expected challenges for persistence of some populations, particularly range restricted and rare species. Current understanding of extinction threat must consider future conditions, and these results highlight the urgent need to protect populations of these six Persoonia species that are currently threatened by habitat destruction and encourage future population persistence through restoration efforts. [ABSTRACT FROM AUTHOR]

Fragmentation of natural vegetation is currently one of the largest threats to plant populations and their interactions with pollinators. Plant reproductive susceptibility to habitat fragmentation has been investigated in many species; however, the response of wild mass‐flowering species is poorly known, with research limited to mainly boreal plant species.Here, we studied twelve remnant populations of the threatened mass‐flowering shrub Conospermum undulatum in the southwest Australian biodiversity hotspot, each presenting different population size, level of isolation, and floral display. We assessed the impact of fragmentation on (a) fruit and seed production; and (b) seed germination. To gain a deeper understanding of factors influencing the reproductive success of C. undulatum, we performed pollinator exclusion and self‐pollination treatments to experimentally assess the mating system of this threatened shrub.We found C. undulatum to be strictly self‐incompatible and totally reliant on pollinators visiting with an outcrossed pollen load to complete the reproductive cycle. Further, we found that fruit production dropped from 35% to <20% as a result of decreasing floral display. A reduction in population size from 880 to 5 plants and from ~700 to 0.21 in the floral display index led to a decrease in seed output, while a similar reduction in seed output, from 6% to 3%, was observed as a result of increasing isolation index from −21.41 to −0.04. Overall, seed germination was positively related to population size, and a negative relationship was found between germination and isolation.Synthesis and applications. Our results demonstrate the important relationship between pollinators and floral morphology in plants of southwest Australia that have coevolved with native pollinators and developed characteristic flower morphologies over long time frames. Indeed, due to its characteristic pollination mechanism, the self‐incompatible C. undulatum can only rely on specialized native pollinators for pollen flow and cannot rely on its mass‐flowering trait to attract generalist pollinators from coflowering species; neither can it compensate for the lack of visitors by promoting geitonogamy. Consequently, fragmentation has a significant effect on the reproductive output of C. undulatum, and size, isolation, and floral display of populations are important factors to be considered when planning conservation actions for the species. [ABSTRACT FROM AUTHOR]

Over 650 Proteaceae occur in south-western Australia, contributing to the region's exceptionally high biodiversity. Most Proteaceae occur exclusively on severely nutrient-impoverished, acidic soils (calcifuge), whilst only few also occur on young, calcareous soils (soil-indifferent), higher in calcium (Ca) and phosphorus (P). The calcifuge habit of Proteaceae is explained by Ca-enhanced P toxicity, putatively linked to the leaf cell-specific allocation of Ca and P. Separation of these elements is essential to avoid the deleterious precipitation of Ca-phosphate. We used quantitative X-ray microanalysis to determine leaf cell-specific nutrient concentrations of two calcifuge and two soil-indifferent Proteaceae grown in hydroponics at a range of Ca and P concentrations. Calcium enhanced the preferential allocation of P to palisade mesophyll (PM) cells under high P conditions, without a significant change in whole leaf [P]. Calcifuges showed a greater PM [P] compared with soil-indifferent species, corresponding to their greater sensitivity. This study advances our mechanistic understanding of Ca-enhanced P toxicity, supporting the proposed model, and demonstrating its role in the calcifuge distribution of Proteaceae. This furthers our understanding of nutrient interactions at the cellular level and highlights its importance to plant functioning. [ABSTRACT FROM AUTHOR]

The Jurien Bay dune chronosequence in south‐western Australia's biodiversity hotspot comprises sites differing in nutrient availability, with phosphorus (P) availability declining strongly with increasing soil age. We have explored the exceptionally high photosynthetic P‐use efficiency (PPUE) of Proteaceae in this region, triggering the question what the PPUE of co‐occurring species in other families might be along the Jurien Bay chronosequence.We explored how traits associated with PPUE, photosynthetic nitrogen (N)‐use efficiency (PNUE) and leaf respiration might converge along the chronosequence, and whether Proteaceae and non‐Proteaceae species differ in leaf traits associated with nutrient use.Seven to 10 species were sampled at three sites differing in nutrient availability (ranging from N‐ to P‐limited). Measurements of leaf light‐saturated photosynthesis and dark respiration were integrated with measurements of total N and P concentration in both mature and senesced leaves, and leaf mass per unit area (LMA).Contrary to what is known for other chronosequences, rates of photosynthesis and respiration did not decrease with increasing soil age and LMA along the Jurien Bay chronosequence. However, they increased when expressed per unit leaf P. Both N and P were used much more efficiently for photosynthesis on nutrient‐poor sites, in both Proteaceae and non‐Proteaceae species. Proteaceae had the fastest rate of photosynthesis per unit leaf P, followed by species that preferentially allocate P to mesophyll cells, rather than epidermal cells.Synthesis. Our results show that with declining soil P availability, photosynthetic P‐use efficiency of all investigated species from different families increased. Plants growing on the oldest, most nutrient‐impoverished soils exhibited similar rates of CO2 exchange as plants growing on more nutrient‐rich younger soils, and extraordinarily high photosynthetic P‐use efficiency. This indicates convergence in leaf traits related to photosynthetic nutrient use on severely P‐impoverished sites. [ABSTRACT FROM AUTHOR]

Dramatic range disjunction of plant populations can have significant genetic consequences that directly influence conservation planning. Genomic technologies provide improved opportunity to investigate genetic variation in species of conservation concern, where small sample sizes often limited the use of previous technologies. In this study, we used 1134 neutral single nucleotide polymorphisms to investigate genomic diversity, differentiation and ancestry across the highly disjunct range of Banksia biterax to identify conservation units and make management recommendations. We also sequenced four non-coding regions of the chloroplast genome to infer phylogeographical history. We found strong genetic differentiation associated with disjunct populations at several geographical scales, but levels of diversity were more influenced by effective population size. Divergent haplotypes and a lack of haplotype sharing indicated that disjunct populations have been historically isolated from the core range of the species. Our data indicate that disjunction can drive strong differentiation but does not necessarily reduce diversity and that disjunct populations of B. biterax represent long-term relicts in the landscape. Three geographical regions should each be considered independent evolutionarily significant units, two of which are of conservation concern. Fire management, pathogen control and ex situ seed storage are key management actions for the long-term persistence of B. biterax. [ABSTRACT FROM AUTHOR]

Identifying the geographic origins of crops is important for the conservation and utilization of novel genetic variation. Even so, the origins of many food crops remain elusive. The tree nut crop macadamia has a remarkable domestication history, from subtropical rain forests in Australia through Hawaii to global cultivation all within the last century. The industry is based primarily on Macadamia integrifolia and M. integrifolia–M. tetraphylla hybrid cultivars with Hawaiian cultivars the main contributors to world production. Sequence data from the chloroplast genome assembled using a genome skimming strategy was used to determine population structure among remnant populations of the main progenitor species, M. integrifolia. Phylogenetic analysis of a 506 bp chloroplast SNP alignment from 64 wild and cultivated accessions identified phylogeographic structure and deep divergences between clades providing evidence for historical barriers to seed dispersal. High levels of variation were detected among wild accessions. Most Hawaiian cultivars, however, shared a single chlorotype that was also present at two wild sites at Mooloo and Mt Bauple from the northernmost distribution of the species in south-east Queensland. Our results provide evidence for a maternal genetic bottleneck during early macadamia domestication, and pinpoint the likely source of seed used to develop the Hawaiian cultivars. The extensive variability and structuring of M. integrifolia chloroplast genomic variation detected in this study suggests much unexploited genetic diversity is available for improvement of this recently domesticated crop. [ABSTRACT FROM AUTHOR]

Natural products isolation studies of eight endemic Tasmanian Proteaceae species - Agastachys odorata, Persoonia juniperina, Hakea megadenia, Hakea epiglottis, Orites diversifolius, Orites acicularis, Orites revolutus, and Telopea truncata - and three endemic Australian Proteaceae species Banksia serrata, Banksia praemorsa, and Banksia marginata were undertaken. Two previously unreported glycoside-derived natural products were identified, in addition to four other tremendously rare arbutin esters. The results of this study provide further evidence consistent with the proposal that these distinctive arbutin esters represent markers that can provide valuable insights into the chemical evolution of plant species within the family Proteaceae., (© 2023 The Authors. Chemistry & Biodiversity published by Wiley-VHCA AG, Zurich, Switzerland.)

Macrobotanical analyses, which offer important information about human-environment interactions of the past, are underdeveloped in Australia due to limited reference materials, poor preservation of organic remains and inadequate field sampling strategies. Wood, seeds, fibres and resin provide invaluable information on diet, technology and human-environment interaction. When excavated from stratified archaeological deposits, macrobotanical remains enable analysis at a scale that is spatio-temporally linked with human occupation, unlike broad-scale palaeo-environmental records, which defy correlation with short-time human responses. Identification and analyses of wood charcoal and seeds from Mount Behn rockshelter, Bunuba country, in the southern Kimberley region of Western Australia, where the largest stone point assemblage for the region was excavated. Neither the anthracological nor carpological records reflect the taxon richness of vegetation communities of the modern vegetation, precluding both palaeo-environmental reconstruction and in-depth exploration of resource management and use. Certain taxa are over-represented in the anthracological and carpological records, in particular, Proteaceae wood charcoal and Celtis spp. endocarps, and we explore how anthracological and carpological spectra are artefacts of preservation, with particular reference to other macrobotanical research that has been conducted in the Kimberley region and Western Australia. [ABSTRACT FROM AUTHOR]

Aims: The Proteaceae are a diverse family of approximately 80 genera and 1700 species with a mostly southern-hemisphere distribution. While distributional patterns of various subsets of the Proteaceae have been studied, no quantitative continental-scale study of species-level spatial biodiversity patterns of the Australian Proteaceae has been conducted. The aim of this study is to identify and examine patterns of distribution, diversity and endemism for the Proteaceae (at family, genera and species levels) of continental Australia and to investigate the environmental drivers for the observed patterns. Methods: Using 151,899 herbarium records for 1179 Australian Proteaceae species, we investigate taxon richness, endemism, and compositional turnover along with climatic and soil correlates. Results: Species richness and endemism was highest in the Southwest phytogeographical region, as well as the Atherton and Southeastern subregions. Genus richness was highest in the Northeastern and Atherton subregions. Highest species turnover occured in the Southwestern region and the Southeastern subregion while lowest species turnover occured in the Northern, Northern Desert and Eremaean regions. Over the entire continent, soil geochemistry and climate explain 37% of the variation in species turnover; however, in areas of high species richness, they account for >75% of the variation in species turnover. Conclusions: These results suggest that the biogeographic patterns of the Proteaceae are impacted by climate and soils, where Proteaceae specialization has filled novel environmental niches associated with low nutrient and low water availability soils, particularly in southwestern Australia. [ABSTRACT FROM AUTHOR]

Due to substantial recent field and taxonomic research, the true biodiversity of plant bugs in the subfamily Phylinae in Australia is only beginning to emerge. This study is a contribution to advancing our understanding of the diversity of plant bugs in Australia. A new genus and five new species of Australian Phylinae are here described, where all species are associated with host plants in the Proteaceae, a family of plants with few well-documented plant bug associates. The new genus Protemiris gen. nov. and the new species P. adenanthi sp. nov., P. conospermi sp. nov., P. distichi sp. nov., P. grevillae sp. nov. and P. isopogoni sp. nov. are mostly restricted to Western Australia, with one species also occurring in the Northern Territory. A morphology-based cladistic analysis confirms the monophyly of this new genus and places it in the recently described subtribe Exocarpocorina of the tribe Semiini, among other Australian phylines with similarly elaborate male and female genitalia. Habitus and scanning electron images, genitalic illustrations, host associations and distribution maps for the new plant bug species are provided. [ABSTRACT FROM AUTHOR]

Cookson (1950) erected the fossil pollen genus Banksieaeidites to accommodate palynomorphs with characters resembling those of the extant Proteaceae genus Banksia. One of the most commonly reported species, Banksieaeidites arcuatus Stover & A.D.Partr., is now known to more closely resemble pollen of the Proteaceae subtribe Musgraveinae, than that of subtribe Banksiinae. The late Eocene Mulga Rock deposits in the southern Officer Basin of Western Australia have yielded palynofloras that contain up to 7% of two new species that can confidently be aligned with pollen of modern Banksia. Banksieaeidites davidsonii sp. nov. and B. rugulus sp. nov. are formally described, and pollen from eight extant Banksia are described and compared with the two fossil species. The variation in extant Banksia L.f. pollen morphology, and that between the two Banksia subgenera (B. subgenus Banksia and B. subgenus Spathulatae A.R.Mast & K.R.Thiele) are discussed, and the changes in the morphology of Banksia pollen grains as they mature are reported. [ABSTRACT FROM AUTHOR]