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Plant persistence and migration in face of climate change depends on successful reproduction by seed, a central aspect of plant life that drives population dynamics, community assembly and species distributions. Plant reproduction by seed is a chain of physiological processes, the rates of which are a function of temperature, and can be modelled using thermal time models. Importantly, while seed reproduction responds to its instantaneous thermal environment, there is also evidence of phenotypic plasticity in response to the thermal history experienced by the plant's recent ancestors, by the reproducing plant since seedling establishment, and by its seeds both before and after their release. This phenotypic plasticity enables a thermal memory of plant reproduction, which allows individuals to acclimatise to their surroundings. This review synthesises current knowledge on the thermal memory of plant reproduction by seed, and highlights its importance for modelling approaches based on physiological thermal time. We performed a comprehensive search in the Web of Science and analysed 533 relevant articles, of which 81 provided material for a meta-analysis of thermal memory in reproductive functional traits based on the effect size Zr. The articles encompassed the topics of seed development, seed yield (mass and number), seed dormancy (physiological, morphological and physical), germination, and seedling establishment. The results of the meta-analysis provide evidence for a thermal memory of seed yield, physiological dormancy and germination. Seed mass and physiological dormancy appear to be the central hubs of this memory. We argue for integrating thermal memory into a predictive framework based on physiological time modelling. This will provide a quantitative assessment of plant reproduction, a complex system that integrates past and present thermal inputs to achieve successful reproduction in changing environments. The effects of a warming environment on plant reproduction cannot be reduced to a qualitative interpretation of absolute positives and negatives. Rather, these effects need to be understood in terms of changing rates and thresholds for the physiological process that underlie reproduction by seed.

Summary Assumptions about the germination ecology of alpine plants are presently based on individual species and local studies. A current challenge is to synthesise, at the global level, the alpine seed ecological spectrum. We performed a meta‐analysis of primary data from laboratory experiments conducted across four continents (excluding the tropics) and 661 species, to estimate the influence of six environmental cues on germination proportion, mean germination time and germination synchrony; accounting for seed morphology (mass, embryo : seed ratio) and phylogeny. Most alpine plants show physiological seed dormancy, a strong need for cold stratification, warm‐cued germination and positive germination responses to light and alternating temperatures. Species restricted to the alpine belt have a higher preference for warm temperatures and a stronger response to cold stratification than species whose distribution extends also below the treeline. Seed mass, embryo size and phylogeny have strong constraining effects on germination responses to the environment. Globally, overwintering and warm temperatures are key drivers of germination in alpine habitats. The interplay between germination physiology and seed morphological traits further reflects pressures to avoid frost or drought stress. Our results indicate the convergence, at the global level, of the seed germination patterns of alpine species.

Overlooked in national reports and in conservation programs, wild food plants (WFPs) have been a vital component of food and nutrition security for centuries. Recently, several countries have reported on the widespread and regular consumption of WFPs, particularly by rural and indigenous communities but also in urban contexts. They are reported as critical for livelihood resilience and for providing essential micronutrients to people enduring food shortages or other emergency situations. However, threats derived from changes in land use and climate, overexploitation and urbanization are reducing the availability of these biological resources in the wild and contributing to the loss of traditional knowledge associated with their use. Meanwhile, few policy measures are in place explicitly targeting their conservation and sustainable use. This can be partially attributed to a lack of scientific evidence and awareness among policymakers and relevant stakeholders of the untapped potential of WFPs, accompanied by market and non-market barriers limiting their use. This paper reviews recent efforts being undertaken in several countries to build evidence of the importance of WFPs, while providing examples of cross-sectoral cooperation and multi-stakeholder approaches that are contributing to advance their conservation and sustainable use. An integrated conservation approach is proposed contributing to secure their availability for future generations.

The thermal thresholds for seed germination identified in this study (T(b) and θ(50)) explained the differences in seed germination detected among populations. Under the two simulated IPCC scenarios, an altitude-related risk from climate warming is identified, with lowland populations being more threatened due to a compromised seed dormancy release and a narrowed seed germination window.

Light conditions provide important information about the best time and place for seedling establishment. Photoinhibition of seed germination (PISG), defined as the partial or complete suppression of germination under white light, has been interpreted as a physiological adaptation to avoid germination at or near the soil surface. This review is the first report of an all-inclusive, fully quantitative analysis of PISG in seed plants. Pertinent data available from the published literature for 301 taxa from 59 families and 27 orders were assessed. The association of PISG with several plant and seed traits allowed us to consider the adaptive significance of PISG in relation to plant life histories and the natural environments. As no gymnosperm has been found to be truly photoinhibited, it seems that PISG is apomorphic to flowering plants (especially monocots). Seeds of most taxa with PISG have a dark colour and intermediate mass, mostly in the range 1 to 27 mg. PISG is absent from humid tropical regions and from cold climates, but it is strongly associated with open, disturbed and dry habitats. An intriguing implication of PISG is the formation of a soil-surface seed bank. Taken together, these results clearly indicate that PISG is a physiological adaptation to avoid germination on the soil surface, where conditions are not suitable for seedling establishment. PISG is probably much more frequent in seed plants than previously thought. Thus, laboratory experiments should be conducted under well-characterized light and dark conditions

Tb and θ50 values facilitated model development of the thermal niche for in situ germination of R. persicifolia. These experimental approaches may be applied to model the natural regeneration patterns of other species growing on Mediterranean mountain waterways and of physiologically dormant species, with overwintering cold stratification requirement and spring germination.