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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., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Annals of Botany Company.)

Morphological variation is common within widely distributed plant species and often raises interesting taxonomic and evolutionary questions. We sampled eight typical inland populations and two coastal dwarf populations of Banksia occidentalis to assess whether the coastal variant warrants taxonomic recognition. Genomic (single nucleotide polymorphisms) and morphometric analyses were undertaken to assess the variation within and between variants. Genetically, the coastal populations were more closely related to geographically adjacent populations of the typical variant than they were to each other, indicating that each coastal population has originated independently. Morphologically, the coastal populations also did not represent a cohesive phenotypic group, with both falling outside the range of variation for the typical variant, but also not overlapping each other. Wide morphological, but not genomic, variation was identified along a coastal–inland transect. Combined, these data indicate that the morphological variation in these coastal populations is the result of parallel ecotype evolution from experiencing similar environmental conditions and does not represent the diversification of a distinct evolutionary lineage that would have warranted taxonomic recognition. Our study highlights the consequences of strong selection pressures in marginal environments and provides fascinating insight to the long evolutionary history of the flora in this ancient Australian landscape. [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]

Morphologically variable species complexes can present significant challenges to conservation when taxonomic boundaries, and therefore conservation units, are ambiguous. In such cases, the definition of Evolutionarily Significant Units (ESUs) based on high-resolution genomic data can be an effective method to clarify genetic divergence and inform conservation actions. Here, we employ a population genomic approach using SNP data to delineate conservation units in a morphologically ambiguous plant species complex (Conospermum caeruleum; Proteaceae) from a global biodiversity hotspot. Over 200 individuals representing five subspecies and three informal morphological forms were sampled across a wide geographic range. Phylogenomic (ML tree and SplitsTree network) and population genomic (STRUCTURE, PCoA, FST) analyses resolved three divergent genetic groups that were incongruent with the current taxonomy, but consistent with geographic distribution. One ESU was comprised of three genetic subgroups, and these can be considered Management Units (MUs) to conserve population genetic structure and diversity. These MUs were surprisingly incongruent with the current subspecies-level taxonomy, but one MU was consistent with a recently documented morphological form, and all were consistent with ecogeographic distribution. We recommend a full taxonomic revision of the Conospermum genus based on a phylogenomic approach to assess any wider incongruence with morphology, and that conservation strategies should be informed by genetic data. Our study exemplifies the application of genomics to the conservation of a morphologically ambiguous species complex, enabling and enhancing the practical conservation of appropriate units of biodiversity. [ABSTRACT FROM AUTHOR]

Ecological restoration is addressing the challenge of biodiversity conservation in landscapes where native vegetation has been extensively cleared. Reestablishing ecological interactions that support self‐sustainable populations plays an essential role in restoration efforts. For animal‐pollinated plant species, comparing mating system dynamics within restoration populations with natural remnant populations can inform the progress of restoration activities. We assessed mating system parameters, seed weight, invertebrate floral visitors, and genetic diversity for two restoration populations and two native reference remnant populations of the animal‐pollinated, woody shrub/tree, Hakea laurina (Proteaceae) in the Southwest Australian Floristic Region. There was no difference in outcrossing rates between the two sites (restoration and reference populations combined) or treatments (sites combined). However, one restoration population showed significantly lower outcrossing that was correlated with reduced seed weight, greater inbreeding, and significantly lower invertebrate richness and abundance compared to its nearby remnant population. In contrast, in the other restoration population, all measures were comparable to the reference remnant population. Local genetic diversity available in remnant populations was captured in both restoration populations. Limitations to pollinator services may be affecting mating patterns and potentially population fitness, in a younger restoration population with reduced proximity to remnant vegetation, which has a tall coplanted overstorey species and spatially aggregated individuals. We highlight these aspects of restoration populations as important areas of ongoing research that will impact the reestablishment of ecological interactions, and the assessment of mating system dynamics as a valuable tool to inform the current progress of restoration activities. [ABSTRACT FROM AUTHOR]

There is an increasing need to establish populations of threatened plants in threat‐free habitat to prevent species extinction. The amount of genetic diversity in founding plants will influence whether the new population has the capacity to persist and evolve over time, and factors that influence the maintenance of genetic diversity, such as the mating systems, will also play a role in population persistence. We developed 13 nuclear microsatellite markers and used these to evaluate genetic diversity and mating system parameters of three translocated populations of two subspecies of Lambertia orbifolia, and compared these parameters to seven wild populations. Genetic diversity was maintained in the translocated population of L. orbifolia subsp. Scott River Plains, established using a single source population (Nar = 3.270 and He = 0.478 in translocated population; Nar = 3.280 and He = 0.534 in wild populations), and maintained or increased in the two admixed translocated populations of L. orbifolia subsp. orbifolia (Nar = 3.115, 3.830 and He = 0.511, 0.635 in translocated populations; Nar = 2.708 and He = 0.438 in wild populations) compared to wild populations of each subspecies. Mating system parameters were comparable between translocated and wild populations of L. orbifolia subsp. Scott River Plains indicating the likelihood of genetic diversity being maintained in future generations. However, there was increased selfing in translocated populations of L. orbifolia subsp. orbifolia, suggesting suboptimal pollination and high values for the inbreeding coefficient in these admixed populations (Fis = 0.474, 0.275), which may be an artifact of the Wahlund effect or from less fit (inbred) seedlings surviving ex situ propagation and translocation. [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]

Fragmentation of plant communities is generally considered to be detrimental to the survival of the constituent species, especially those that are rare. We investigated the effects of fragmentation on reproductive biology in nine populations of the rare taxon Banksia nivea subsp. uliginosa , differing in size and habitat context. Small mammals were the main pollinator, with lower contributions from honeybees and birds (honeyeaters). There was no significant relationship between population size, fruit set and seed germinability. Fruit set was marginally highest (25.5 ± 3.4) in medium size populations and was variable over years. Lower fruit set (1.0 ± 0.6) in the smallest population may be due to inbreeding depression or lack of pollinators in a degraded habitat, but low fruit set was also observed in the largest population despite high levels of gene flow, possibly due to low pollinator visitation rate in a low-density population. Seeds from all populations had high germination success (>93.4%). Predation occurred in up to 56% of fruit and increased with increasing population size, but was not significantly different between populations of different size. Our study provided evidence that the reproductive output in species in a naturally fragmented landscape system may be resilient to reduced population size and other influences of anthropogenic fragmentation. [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]

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]

We used a comparative approach to assess congruence of phylogeographic and genetic structure and diversity, demographic signals, and ratios of pollen to seed dispersal, in the context of species-specific life-history traits, for two widespread sympatric perennial plant species. We sampled Grevillea paradoxa and Melaleuca nematophylla across the species' ranges throughout the Transitional Rainfall Zone and extending slightly into the Arid Zone of southwest Western Australia. Both species exhibited range-wide phylogeographic and contemporary genetic structure. Moderate haplotype diversity centred in populations on Banded Ironstone Formation (BIF) outcrops and within the Murchison River gorge supports a hypothesis of historical persistence and evolution in these mesic refugia. These features are likely to play important roles in evolutionary persistence with ongoing climate change. There was little evidence of particularly complex demographic histories for the region. More limited haplotype diversity, as well as more limited nuclear genetic diversity and connectivity, in G. paradoxa was consistent with predictions from life-history traits of shorter lifespan, lower fecundity, more limited seed dispersal, and shorter plants, but inconsistent with a prediction of greater pollen dispersal by bird pollinators. Low pollen to seed dispersal ratios suggest seed dispersal plays a greater than expected role in maintaining connectivity in this semi-arid landscape. The study highlights a need for research that integrates aspects of seed ecology and seed and pollen dispersal as well as phylogeographic and genetic patterns in Gondwanan shrublands and other semi-arid landscapes globally. [ABSTRACT FROM AUTHOR]

Comparative studies of sympatric species that integrate both phylogeographical and population genetic approaches provide insight into how demographic events and life history traits shape adaptive potential and drive species persistence. Such studies are rare for species-rich and strongly structured environments, especially those of the southern hemisphere. For two sympatric, perennial shrubs of the south-west Western Australian semi-arid zone, Grevillea globosa and Mirbelia sp. Bursarioides, we assessed historical and contemporary genetic diversity and structure, demographic processes and ratios of pollen to seed dispersal. Phylogeographical structure was not detected and haplotype networks were star-like. Number of haplotypes, nucleotide diversity, haplotype diversity, and allelic diversity were statistically significantly lower for G. globosa than for M. sp. Bursarioides. Levels of haplotype divergence and more contemporary genetic divergence and expected heterozygosity were lower for G. globosa than for M. sp. Bursarioides, but differences were not statistically significant. Both species exhibited signals of isolation by distance and low pollen to seed dispersal ratios (5.26:1 and 6.88:1). Grevillea globosa displayed signals of historical and contemporary demographic expansion. Results imply an important role for aspects of seed ecology that impact population demography, as well as direct dispersal and a significant contribution of seed dispersal to genetic connectivity in a semi-arid landscape. [ABSTRACT FROM AUTHOR]

The genetic structure of disjunct populations is determined by founding genetic properties, demographic processes, gene flow, drift and local selection. We aim to identify the genetic consequences of natural population disjunction at regional and local scales in H akea oldfieldii using nuclear and plastid markers to investigate long-term effective population sizes and gene flow, and patterns of diversity and divergence, among populations. Regional divergence was significant as shown by a consistent pattern in principal coordinates, neighbor-joining and Bayesian analyses, but divergence at the local level was also significant with localized distribution of plastid haplotypes and populations clustering separately in Bayesian analyses. Historical, recent and first-generation gene flow was low, suggesting that recent habitat fragmentation has not reduced gene migration significantly. Genetic bottlenecks were detected in three populations. Long-term effective population size was significantly correlated with the number of alleles/locus and observed heterozygosity, but not with census population size, suggesting that the loss of diversity is associated with long-term changes rather than recent fragmentation. Inbreeding coefficients were significant in only three populations, suggesting that the loss of diversity is linked to drift and bottlenecks associated with demographic processes (local extinction by fires) rather than inbreeding. Historical disjunction as a result of specific ecological requirements, contraction of habitats following drying during the Pleistocene, low gene flow and changes in population size are likely to have been important forces driving divergence through isolation by distance and drift. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179, 319-334. [ABSTRACT FROM AUTHOR]

Plant species distributed across terrestrial islands can show significant genetic divergence among populations if seed and pollen dispersal are restricted. We assessed the genetic connectivity between populations of Grevillea georgeana, restricted to seven disjunct inselbergs in semi-arid Western Australia. The phylogeographical pattern and population genetics of populations were determined using sequence data from two plastid DNA intergenic spacers and ten nuclear microsatellite loci. The plastid DNA markers indicated high genetic differentiation among the majority of populations. Haplotypes were restricted to individual inselbergs, with the exception of two that were shared among three isolated populations that formed part of an elongated greenstone belt and that may be connected via inaccessible populations of G. georgeana. There was also strong differentiation within some of the populations, suggesting long-term isolation and persistence of G. georgeana on these terrestrial islands. Overall, the genetic patterns suggest limited seed dispersal, with differentiation in the plastid DNA genome being driven by genetic drift. In contrast, pollen movement, although generally restricted, may occur between neighbouring populations, resulting in a pattern of isolation by distance in the nuclear markers. This potential for limited or no seed dispersal, but connectivity via pollen flow, should be considered, given that many of the inselbergs are under consideration for resource development. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 178, 155-168. [ABSTRACT FROM AUTHOR]

The Banded Iron Formations ( BIFs) of south-western Australia are terrestrial islands characterized by high species richness and endemism. Regional endemics occur across multiple formations without inhabiting the intervening landscape matrix. We investigated whether the occurrence on BIF terrestrial islands has led to genetic differentiation among the eight known populations of the regional endemic, Banksia arborea. Genetic structure was assessed using three chloroplast DNA sequence markers and 11 nuclear microsatellite loci. Phylogenetic relationships were assessed with statistical parsimony and Bayesian methods. Dates of haplotype divergence were estimated using the time to most recent common ancestor of B. arborea and Banksia purdieana, as well as a conservative angiosperm chloroplast (cp) DNA mutation rate. Population genetic diversity and structure was assessed amongst and within populations by genotyping 24 geographically clustered individuals from each BIF and three subpopulations within the Die Hardy Range BIF. Indirect gene flow estimates were determined using a method based on the frequency of private alleles. Banksia arborea showed low genetic diversity in (cp) DNA and a complex structural pattern, with genetic differentiation of some BIF populations and an absence of differentiation amongst others, reflecting either retention of ancestral polymorphism across northern BIF populations or more recent connectivity of these populations. There was little evidence of pollen dispersal both between BIFs and within the large BIF known as Die Hardy Range. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114, 860-872. [ABSTRACT FROM AUTHOR]

Subspecies are traditionally defined using phenotypic differences associated with different geographical areas. Yet patterns of morphological and genetic variation may not coincide and thereby fail to reflect species' evolutionary history. The division of the shrub Banksia nivea Labill. into one widespread (B. nivea subsp. nivea) and two geographically localized subspecies (B. nivea subsp. uliginosa (A.S. George) A.R. Mast & K.R. Thiele and B. nivea subsp. Morangup (M. Pieroni 94/2)) in south-west Australia has been based mainly on variation in leaf shape and pistil length, although flowering time and habitat differences are also evident, and subsp. uliginosa occurs on a different substrate. To assess the genetic divergence of B. nivea subspecies, we genotyped representatives from each subspecies for nuclear microsatellite and non-coding chloroplast sequence variation. We used distance and parsimony-based methods to assess genetic relatedness. Patterns were consistent with the existing taxonomy of subsp. nivea and uliginosa but not subsp. Morangup. Phylogenetic analyses revealed evidence for a more recent divergence of subsp. uliginosa associated with expansion from dryer sandy soils into the winter-wet ironstone soils in the southwest of Western Australia, consistent with progressive long-term climatic drying. Nuclear microsatellites showed low to moderate diversity, high population differentiation overall, and genetic structuring of subspecies in different biogeographical areas. We propose this pattern reflects the predicted impact of a patchy distribution, small populations, and restrictions to gene flow driven by both distance and biogeographic differences in subspecies' habitats. [ABSTRACT FROM AUTHOR]

Premise: Recent habitat fragmentation is posing a risk to the wavy‐leaved smokebush, Conospermum undulatum (Proteaceae), a rare plant species endemic to southwestern Western Australia. Microsatellite markers are required to characterize the genetic diversity and structure of the species for conservation purposes and to facilitate ecological studies. Methods and Results: Illumina MiSeq high‐throughput sequencing was used to develop 20 novel microsatellite markers for C. undulatum. Polymorphism at each locus was assessed using 72 individuals from three natural populations. Nineteen markers were polymorphic, with the number of alleles per locus ranging from two to 21, and observed and expected heterozygosity ranging from 0.000 to 1.000 and 0.117 to 0.919, respectively. All markers successfully amplified in three congeneric species (C. stoechadis, C. canaliculatum and C. triplinervium). Conclusions: The microsatellite markers will be useful for revealing patterns of genetic diversity, dispersal dynamics, and hybridization events for C. undulatum to inform future conservation efforts. [ABSTRACT FROM AUTHOR]

• Disruption of pollination services has been investigated in many species; however, fragmentation-induced effects on endemic plants that rely on species-specific invertebrate pollinators are still unclear. While honeybees can forage over long distances, many native bees with small body size are unable to extend their foraging range, making habitat fragmentation the largest threat to such systems. • Here, we defined the pollinator assemblage of our target species, Conospermum undulatum (Proteaceae), among remnant populations characterized by different degrees of fragmentation. We explored the impact of fragmentation on flower visitation in eleven populations of C. undulatum. Lastly, we took advantage of the fragmentation gradient to tease apart the influences of pollen quantity and quality on pollen limitation. • Small populations showed an impoverished pool of weakly effective pollinators. Flower visitation increased from 1.5% to 74.3% with increasing floral display index, while it increased from 1.3% to 5.6% with increasing connectivity levels of populations. We found evidence of pollen quantity limitation across all the populations; however, the overall pollen limitation was greater in small fragments where genetic factors limited the quality of pollen. • Native bees were absent in small isolated remnants. Our study highlights the importance of such pollinators for plants that coevolved with them. The availability of compatible pollen is limited in small remnant populations and native pollinators appeared unable to maintain an adequate inter-population pollen flow in heavily fragmented landscapes. The effects of habitat fragmentation can be exacerbated in small and isolated populations of plants that rely on species-specific pollinators for sexual reproduction. [ABSTRACT FROM AUTHOR]