Summary: Trait‐based approaches have improved our understanding of plant evolution, community assembly and ecosystem functioning. A major challenge for the upcoming decades is to understand the functions and evolution of early life‐history traits, across levels of organization and ecological strategies. Although a variety of seed traits are critical for dispersal, persistence, germination timing and seedling establishment, only seed mass has been considered systematically. Here we suggest broadening the range of morphological, physiological and biochemical seed traits to add new understanding on plant niches, population dynamics and community assembly. The diversity of seed traits and functions provides an important challenge that will require international collaboration in three areas of research. First, we present a conceptual framework for a seed ecological spectrum that builds upon current understanding of plant niches. We then lay the foundation for a seed‐trait functional network, the establishment of which will underpin and facilitate trait‐based inferences. Finally, we anticipate novel insights and challenges associated with incorporating diverse seed traits into predictive evolutionary ecology, community ecology and applied ecology. If the community invests in standardized seed‐trait collection and the implementation of rigorous databases, major strides can be made at this exciting frontier of functional ecology.

Ex situ seed conservation aims to support species survival in the wild. This can be achieved by contributing genetic material for reintroduction. The goals of reintroduction are to increase both plant and population numbers, create self-sustaining populations and ultimately remove a species from its threatened listing. Quality seed collections with a broad genetic base are required to achieve this goal. Storage conditions that minimise deterioration of seeds will maximise the quality of seeds available for future use. Additionally, ex situ seed conservation provides long-term insurance against species or genotype loss until actual or potential threats can be removed. As threats to biodiversity escalate the most judicious conservation strategies will be ones that combine available resources to provide the highest possible degree of protection. Banked seeds are available irrespective of season and periods of low fecundity. Forward planning of reintroduction projects can be achieved with knowledge of the quantity and quality of banked seed. This paper discusses the challenges facing ex situ seed conservation while highlighting the benefits of integrating ex situ seed storage and plant reintroduction to help provide for better conservation outcomes.

In obligate seeding species, the germination niche is crucial for colonization and population survival. It is a high-risk phase in a plant's life cycle, and is directly regulated by temperature. Seeds germinate over a range of temperatures within which there is an optimum temperature, with thresholds above and below which no germination occurs. We suggest that abrupt changes in temperature associated with a warming climate may cause a disconnect between temperatures seeds experience and temperatures over which germination is able to occur, rendering obligate seeding species vulnerable to decline and extinction. Using a bidirectional temperature gradient system, we examined the thermal constraints in the germination niche of some geographically restricted species from the low altitude mountains of the Stirling Range, southern Western Australia, including seedlots from lowland populations of four of these species. We demonstrated that high temperatures are not a limiting factor for germination in some restricted species, signifying a lack of relationship between geographic range size and breadth of the germination niche. In contrast, we identified other restricted species, in particular Sphenotoma drummondii, as being at risk of recruitment failure as a consequence of warming: seeds of this species showed a strong negative relationship between percentage germination and increasing temperature above a relatively low optimum constant temperature (13°C). We found some ecotypic differences in the temperature profiles between seeds collected from montane or lowland populations of Andersonia echinocephala, and while specific populations may become more restricted, they are perhaps at less risk of extinction from climate warming. This seed-based approach for identifying extinction risk will contribute tangibly to efforts to predict plant responses to environmental change and will assist in prioritizing species for management actions, directing limited resources towards further investigations and can supplement bioclimatic modelling.

The Southwest Australian Floristic Region (SWAFR) is a global biodiversity hotspot with high plant diversity and endemism and a broad range of threatening processes. An outcome of this is a high proportion of rare and threatened plant species. Ongoing discovery and taxonomic description of new species, many of which are rare, increases the challenges for recovery of threatened species and prioritisation of conservation actions. Current conservation of this diverse flora is based on integrated and scientific evidence-based management. Here we present an overview of current approaches to the conservation of threatened flora in the SWAFR with a focus on active management through recovery and restoration that is integrated with targeted research. Key threats include disease, fragmentation, invasive weeds, altered fire regimes, grazing, altered hydro-ecology and climate change. We highlight the integrated approach to management of threats and recovery of species with four case studies of threatened flora recovery projects that illustrate the breadth of interventions ranging from In situ management to conservation reintroductions and restoration of threatened species habitats. Our review and case studies emphasise that despite the scale of the challenge, a scientific understanding of threats and their impacts enables effective conservation actions to arrest decline and enhance recovery of threatened species and habitats.

The storage of seeds is a commonly used means of preserving plant genetic diversity in the face of rising threats such as climate change. Here, the findings of research from the past decade into thermal requirements for germination are synthesised for more than 100 plant species from southern Western Australia. This global biodiversity hotspot is predicted to suffer major plant collapse under forecast climate change. A temperature gradient plate was used to assess the thermal requirements underpinning seed germination in both commonly occurring and geographically restricted species. The results suggest that the local climate of the seed source sites does not drive seed responses, neither is it indicative of temperatures for optimal germination. The low diurnal phase of the temperature regime provided the most significant impact on germination timing. Several species germinated optimally at mean temperatures below or close to current wet quarter temperatures, and more than 40% of species were likely to be impacted in the future, with germination occurring under supra-optimal temperature conditions. This research highlights both species vulnerability and resilience to a warming climate during the regeneration phase of the life cycle and provides vital information for those aiming to manage, conserve and restore this regional flora.

A risk-assessment tool was used to investigate the risk of extinction from disease caused by Phytophthora cinnamomi to 33 taxa from the Stirling Range National Park, Western Australia. Criteria used to score risk of extinction were the direct impact of P. cinnamomi on taxa, number of extant or extinct populations, percentage of populations infested by P. cinnamomi, proximity and topographical relationship of populations to P. cinnamomi, proximity of populations to tracks and the number of additional threatening processes. Direct impact scores were derived from mortality curves determined from the survival of taxa after soil inoculation with P. cinnamomi in a shade-house environment. On the basis of the total extinction risk score, nine taxa had a ‘very high’, five had a ‘high’, six a ‘moderate’, eight a ‘low’, four a ‘very low’ and one ‘no’ risk of extinction. Whereas the methodology confirmed the current threatened status of nine taxa, it also identified five taxa, not currently listed, to be at ‘high’ risk of extinction. Other threatening processes identified included fire, herbivory, aerial canker disease and climate change. These combine with P. cinnamomi to push taxa further towards extinction. Quantification of risk of extinction identifies taxa at risk and allows for prioritisation of management actions for currently threatened flora. This risk-assessment methodology combined glasshouse inoculation with habitat and ecological data, current in situ disease impact and proximity to disease and vectors, to enable a more comprehensive assessment of extinction risk and may be used in other areas with endemic flora threatened by P. cinnamomi.