Regeneration from seeds in a temperate native flora: A climate‐smart and natural–capital‐driven germination risk modelling approach

Abstract

Societal Impact StatementExceptionally rainy winters and hot–dry summers are becoming the new normal around the United Kingdom. The effects of these climatic changes can already be seen in forests and grasslands, agricultural fields and even in our own gardens, as native plants try to keep pace with them. In this study, the seed germination of the native flora of Wakehurst, in the Southeast England, was analysed to identify potential threats to the long‐term persistence of selected species, which are part of the natural landscape of this area. Recommendations are provided for ecological restoration interventions which aim to maintain the different potential benefits those plants can provide to people.Summary Seeds play an important role in plant adaptation to human‐driven climate change. In this study, we applied a multilevel modelling of thermal germination responses of native temperate plants, to understand how global warming could affect their reproduction and the potential benefits they provide, as part of their natural capital. We identified Wakehurst (Southeast England, UK), as our study system. We modelled thermal seed germination parameters of the native flora as a whole and according to different uses categories (e.g., medicinal or food plants), through a phylogenetic meta‐analysis of publicly available data from Kew's Millennium Seed Bank (MSB). We also carried out a comparative germination study for MSB seed lots of 20 selected species. Finally, we quantified the germination risk, by comparing current and predicted environmental temperatures with thermal germination parameters at flora, uses categories and species level. Under future climatic scenarios, germination of the native flora will be at higher risk in spring than in autumn. Fitted quadratic models, although affected by phylogeny, did not show major differences among uses categories. Species with a narrow window of cold germination temperatures could be more at risk than those with warm optimal temperatures. Restoration activities should target species from phylogenetically clustered uses categories, to avoid losing their benefit provisions, and implement climate‐smart seed sourcing for high‐risk species. This multilevel germination modelling approach, based on collections and available data from conservation seed banks, can be applied to selected floras and regions to inform climate‐smart ecological restoration activities, while accounting for their natural capital.

MedGermDB: A seed germination database for characteristic species of Mediterranean habitats

“…Particularly, we expect to quantitatively test the main cold-cued germination syndrome of the Mediterranean flora (Thanos et al, 1989;Picciau et al, 2019;Carta et al, 2022) and identify germination optima across species and habitats. We also envisage the use of this kind of data to forecast plant responses to current and future climatic conditions (Sentinella et al, 2020;Mattana et al, 2023).…”

Verified hypotheses on the “nurse” and “burial” effects on introduced Quercus rubra regeneration in a mesic Scots pine forest

“…Successful seed germination and seedling development are crucial for species survival, as the highest mortality of plants is observed in these two stages of plant regeneration (Jia et al., 2020 ; Mattana et al., 2023 ; Yan et al., 2015 ). In the case of commercially important woody species intentionally planted outside their native range, the successful development of juvenile specimens from seeds, naturally dispersed or collected and sown directly to the ground, also has a fundamental meaning for forest management due to the interest in less costly regeneration of stands (Löf et al., 2019 , 2021 ; Pötzelsberger et al., 2020 ).…”