Thierry Vanderborght

Plant reintroductions: the need for a global database

Plant reintroductions include labor-intensive, costly, and time-consuming work and often cannot guarantee a successful outcome. In order to maximize the chances of success, it is therefore of utmost importance to appropriately select target species, release site, cultivation and reintroduction methodology, and management technique of the out-planting site. Case studies, best practice and experiences of plant reintroductions are however not sufficiently disseminated to the plant conservation community, most often remaining in unpublished internal reports to which access is difficult. We suggest that this is a major problem for conservationists and it requires the establishment of a framework for rapid and effective broadcasting of information on plant reintroduction programs. We propose a set of variables for a centralized web-based interface which could provide the necessary information in a standardized and accessible form.

Seed banking of endangered plants: Are we conserving the right species to address climate change?

The increasing awareness of the effects of climate change on plant distributions in situ has made the appropriate application of ex situ techniques more crucial. These ex situ conservation techniques need to be targeted to priority species identified at risk from climate change. The present paper assesses the sensitivity of plant species to climate change in Belgium and explores the current conservation status of those species potentially vulnerable to climate change. We then checked whether these species were included in ex situ collections. The whole Belgian flora has been assessed (a total of 1,396 native plant species). We evaluated whether each of these species occurs in a “climate change-vulnerable” habitat, having therefore a higher probability to be impacted by climate change. The assessment revealed that there are at least 415 native plant species (30% of the Belgian native flora) that appear to be vulnerable to climate change during the next decades. Results also showed that about one-third of the species currently included in the red list may have their situation made potentially worse due to climate change. In addition, depending on the region, between 45 and 67% of the species that are currently not threatened in Belgium are likely to become so due to climate change. It also appeared that only 32% of these climate change-vulnerable species are currently held ex situ. We conclude that there is a need to identify gaps in existing ex situ collections as an urgent priority and ensure that species potentially vulnerable to climate change are conserved ex situ.

Ex situ cultivation entails high risk of seed dormancy loss on short‐lived wild plant species

Changes in life-history traits such as seed dormancy during cultivation of wild plant species in ex situ facilities could jeopardize conservation actions including revegetation and plant reintroductions, but the magnitude of these risks and their spread across different plant taxa is unknown. We explored whether plants cultivated in the Botanic Garden Meise differ in seed germination characteristics from plants from natural populations. Using a Bayesian approach of a phylogenetically informed generalized linear mixed model, we analysed germination tests of 72 herbaceous plant species from 27 plant families, originating from the cultivation beds in Meise as well as directly from wild populations. We investigated whether garden-collected seeds differ in germination percentage, seed dormancy and germination speed from wild-collected seeds. Furthermore, by analysing literature-collected information of 24 life-history traits, we sought to identify potential selection pressures causing these germination changes in order to refine conservation protocols and practices. We found a strong increase of germination percentage and a loss of seed dormancy in garden seeds compared to wild seeds across all species. However, these differences vanished with increasing storage time of the seeds as a result of decreased seed viability with seed ageing over time. Furthermore, traits associated with the life span of the species influenced the germination difference between cultivated and wild seeds, and short-lived species were particularly vulnerable to the loss of dormancy, while no difference could be detected between wild and cultivated perennial species. Synthesis and applications. Through a multispecies approach, we show that dormancy loss is a common phenomenon in ex situ collections of short-lived wild plant species. This has wide implications for the use and procedure of ex situ-reared plant material for restoration and reintroduction measures. We suggest that effective dormancy breaking and temporal distribution of seedling plantation during propagation should be incorporated in restoration and reintroduction protocols to minimize unwanted changes in seed traits. Furthermore, we caution against the use of seeds from cultivated plants for basic seed ecology research such as germination requirements and seed storage behaviour.

Effectiveness of dry heat as a seed sterilisation technique: Implications for ex situ conservation

Abstract Seed-borne pathogens are a daily issue for ex situ collection managers who try to solve it using various chemicals more or less harmful to the staff and the plant material stored. The most common physical method for seed sterilisation is moist heat, in contrast to dry heat which is used much less frequently. Consequently, the efficiency of dry heat as disinfection method and the behaviour of seeds undergoing this treatment are currently poorly known, especially for wild species. In this study, seed viability was estimated by performing germination tests according to standard procedures. Germination tests were conducted on 13,200 seeds from 66 wild species of temperate regions belonging to 22 different families. Results indicate that dry seeds exposed to 60°C during 1hour were less infected by seed-borne pathogens in 14% of the cases, whereas no change has been registered in the other cases. For all 66 studied species, no decrease in germination percentage was detected after the heat treatment. Given its positive effect on infection control without affecting seed viability, dry heat treatment as proposed here opens opportunities for seed bank managers, but also for the disinfection of herbarium collections.