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We introduce the AusTraits database - a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field campaigns, published literature, taxonomic monographs, and individual taxon descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological attributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised individual- and species-level measurements coupled to, where available, contextual information on site properties and experimental conditions. This article provides information on version 3.0.2 of AusTraits which contains data for 997,808 trait-by-taxon combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data, which also provides a template for other national or regional initiatives globally to fill persistent gaps in trait knowledge.

Zieria buxijugum , Z. formosa , and Z. parrisiae are three closely related, Critically Endangered species of questionable taxonomic validity that occur within six kilometres of each other on the south coast of New South Wales, Australia. We investigated genetic relationships and diversity of these species, along with two related but taxonomically distinct congeners, Z. granulata and Z. tuberculata , and a possible undescribed taxon, Z. aff. tuberculata. Double-digest restriction-site associated sequencing (ddRADseq) was used to generate anonymous genomic loci that were used for phylogenetic, network, and genetic structure analyses, and for estimating genetic diversity of the threatened species. Our results support the current taxonomic status of Z. buxijugum , Z. formosa , and Z. parrisiae , and suggest that Z. aff. tuberculata warrants recognition as a distinct species. We detected no evidence of inbreeding in the three Critically Endangered species, and found their genetic diversity to be similar to that of the more widespread species Z. granulata and Z. tuberculata. Comparison of plant material held in ex situ collections at the Australian National Botanic Gardens with wild plants highlighted several genotypes of the Critically Endangered species that are not represented in the ex situ collection, and we provide suggestions for the future inclusion of those unrepresented genotypes. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Conservation seed banks maintain collections of many seed‐bearing plant species, providing germplasm and data to support management of wild populations. However, a proportion of plant species produce seeds that are difficult to collect, dry, store and utilise; these are known as 'exceptional' species. Here we tested a framework for identifying exceptional species, to document examples and provide case studies within the Australian flora. We present a workflow that may be used to identify additional exceptional species, and direct efforts to establish appropriate collection types (seeds and/or living collections, tissue culture or cryopreservation) for their ex situ conservation. Summary: Seed banking is well established to contribute to the conservation of many seed‐bearing plant species ex situ for future use in restoration, translocation, agriculture and horticulture. In Australia, over 67% of currently listed threatened plants are represented in conservation seed banks. However, there are challenges to conserving the full extent of plant diversity in seed banks, with growing recognition that we need to think beyond conventional seed banking methods to conserve 'exceptional' plant species that are difficult to collect, store and germinate. We examine how the framework for identification of such species can be applied to the Australian flora, using examples from the recently published guidelines for 'Plant Germplasm Conservation in Australia' and case studies and data arising from the Australian Academy of Science Fenner Conference on the Environment 'Exceptional Times, Exceptional Plants'. We present a workflow to assist conservation decision‐makers and practitioners in identifying exceptional species and overcoming barriers to storage of germplasm, enabling appropriate ex situ collection types to be established via seeds, living collections, tissue culture, cryopreservation or a combination of these. Australia's seed conservation sector continues to expand, with increasing expertise, facilities and networks established to conserve a diversity of plant species; however, resolving the challenges relating to each exceptionality factor requires significantly more time, labour and collaboration than current capacity allows. Understanding the barriers to conservation and production of healthy plants, via germination or other methods of propagation, is a critical component of conserving species long‐term and ultimately returning plants to the landscape. [ABSTRACT FROM AUTHOR]

Context. The Cumberland Plain Woodland (CPW) is a threatened ecological community that is expected to experience heatwaves of increasing intensity and frequency into the future. Given the central role that temperature plays in regulating seed germination, understanding the impacts of such heatwaves on key germination attributes is vital to identify potential impacts on plant community structure. Aims. To determine the impacts of increased heatwave intensity and frequency treatments on seed germination within and across 15 native species of the CPW. We also examined the influence of interspecific variation in life-history traits on germination responses. Methods. Seeds were exposed to seven heatwave treatments of increasing intensity and frequency. Life-history trait data were also collected for each species' dormancy type, fire response traits, life form and seed mass. Key results. There was evidence within the study species of a significant effect of heatwave treatment. Germination duration was prolonged for the two most extreme simulated heatwave events. Life-history traits could not explain germination responses after heatwave treatments, however, larger seeded species had quicker germination onset and shorter periods of germination over small-seeded species; and trees had lower proportions of germination than any other life form. Conclusions. Increases in heatwave intensity and frequency have an impact on seed germination responses in native species of the CPW. Life-history traits could not explain germination responses across species along the heatwave gradient. Implications. Projected increases in heatwave intensity and frequency are likely to impact seed germination, and thus community composition, in species from the CPW. [ABSTRACT FROM AUTHOR]

Context. Seeding is common practice for ecological restoration, but establishment rates can be low. For seeds to successfully establish they must transition through early life stages of germination, emergence, and (initial) survival. Examining these demographic processes for seeds sown under a range of abiotic conditions can identify failure points and inform techniques to improve seed use. Aims. Here we quantified seed and seedling life-stage transitions in five reconstructed soils across four varying levels of simulated rainfall using five species (Acacia hilliana, Acacia inaequilatera, Indigofera monophylla, Triodia pungens, and Triodia wiseana) commonly seeded for mined land restoration of the Pilbara bioregion in north-west Western Australia. Methods. Germination, emergence, and survival were measured over a 6 week period and transition probabilities between each life-stage transition were modelled for each treatment combination. Key results. For four species, both rainfall amount and/or soil substrate significantly influenced germination probability. Rainfall was the more significant determinant, with germination greatest under the higher rainfall regimes of 120-280 mm, irrespective of soil type. Following germination, emergence of both Acacia spp. was positively influenced by soils containing topsoil, suggesting the microenvironment of soils containing topsoil was most favourable during this emergence phase. The effect of substrate was less clearcut for I. monophylla and Triodia spp, where emergence was most limited in substrates comprised solely of overburden waste material and the lowest rainfall regime exacerbated emergence failure, relative to germination success. When compared to the well-watered, 100% topsoil substrate, seedling survival of all species was most constrained in the 100% overburden waste, demonstrating these reconstructed mining substrates compromise seedling recruitment. Conclusions. This study underscores that successful seedling recruitment in this ecosystem is dependent on frequent, and repeated, rainfall events above a certain threshold (≥120 mm) and highlights the beneficial effects of sowing seeds in a substrate containing topsoil. Implications. Future seeding technologies should focus on improving the moisture relations of the microsite to offset the recruitment challenges experienced by seeds sown in hostile growing environments such as the overburden wastes tested here. [ABSTRACT FROM AUTHOR]

Context. Seeds harbour a diversity of microbes, which in some plants aid with germination and establishment. Seeds form a critical part in the lifecycle of plants and a role in many conservation and restoration activities. Aims. Because this is an emerging field in seed biology, we aim to highlight the key research gaps of interest to seed on the basis of restoration and ex situ conservation. Methods. We identify knowledge gaps associated with the seed endophytic microbiome of native Australian plants through undertaking a literature review. Additionally, culturing methods were used to identify the fungal seed endophytes of five native Australian species. Key results. We identified a diversity of taxa within the native seed and show three taxa that are common to all study hosts. Sampling seed from additional hosts at a site and additional sites of a host species showed new fungal diversity. Our literature review showed that little information is available on native seed microbiomes and we identified four key areas where research gaps exist, linking with seed-based restoration practices. Conclusions. We provide evidence that there is a complex and diverse seed microbiome within some Australian native plants and suggest ways that it could be integrated into restoration and conservation practices. Implications. We propose that by taking into consideration the presence of a seed microbiome and its potential impacts on plant health, seed microbiomes could be used as one method to restore microbial diversity into an ecosystem and to contribute to the seedling microbiome and plant health at restored sites. [ABSTRACT FROM AUTHOR]

Context. Fifty per cent of Australian rainforest species produce orthodox seeds, but little is known about their longevity in storage. Aims. To (1) estimate the longevity of seeds of 33 rainforest species using artificial aging; (2) assess the influence of habit, habitat range (restricted to rainforest or more broadly distributed), seed characteristics (endospermy, dry weight), and collection environment (e.g. precipitation, elevation and average temperature) on longevity; (3) compare longevity of rainforest seeds to previously assessed species from non-rainforest habitats; (4) compare longevity in artificial aging to real-time longevity in storage. Methods. Seeds were aged at 60% relative humidity and 45°C, and tested at pre-determined intervals until germination was reduced to zero. The time taken for germination to decline to 50% (p50AA) was calculated by probit analysis. Ordinary least-squares regression was used to model p50AA for rainforest and non-rainforest species against predictor variables. Values for p50AA were then compared with the actual longevity in storage at -20°C (p50RT) using Pearson's correlation. Key results. Species restricted to rainforest exhibited a significantly lower p50AA than species with a wider distribution or those restricted to non-rainforest habitats. Collection elevation had a significant negative influence on p50AA. In all, 14 of 33 species showed a significant decline in viability after ≤12 years in storage. Values of p50AA were not correlated with p50RT. Conclusions. Rainforests contain a high proportion of potentially, and actually, short-lived species; however, p50AA is not a good predictor of their real-time longevity. Implications. Rainforest species should be managed as short-lived, with viability checked at least every 5 years, until real-time longevity data indicate otherwise. [ABSTRACT FROM AUTHOR]

Seed science is a vital field of research that contributes to many areas of knowledge in fundamental ecology and evolution, as well as in applied areas of food production, and the conservation and restoration of native plants. A large amount of novel information, technologies and processes in seed science research are being produced and developed by early to middle career researchers (EMCRs) in academic, government and private science sectors. This breadth and novelty of research by EMCRs was evident at the second Australasian Seed Science Conference held online in September 2021. EMCRs represented almost one-third of the presenting delegates at the conference and covered research in areas including functional seed trait relationships, responses of seed traits and germination to environmental change, managing seeds in ex-situ seed and germplasm collections and using seeds as food sources. As future environmental, social and economic challenges arise, EMCR seed scientists will be at the forefront of emerging fundamental ecological and evolutionary seed science knowledge, as well as the development of technologies and processes for the conservation of native species, the utilisation of seeds in agriculture and food production, and many new ideas yet to be discovered. [ABSTRACT FROM AUTHOR]

The article discusses the ex situ conservation breakthrough at the Australian National Botanic Gardens, highlighting the successful acquisition of viable seeds for the highly exceptional species, the Endangered Muehlenbeckia tuggeranong, through a combination of living collections and seed biology research. This achievement has opened up various research avenues to further support the conservation of this unique species.