Reversing extinction trends: new uses of (old) herbarium specimens to accelerate conservation action on threatened species.

Although often not collected specifically for the purposes of conservation, herbarium specimens offer sufficient information to reconstruct parameters that are needed to designate a species as 'at-risk' of extinction. While such designations should prompt quick and efficient legal action towards species recovery, such action often lags far behind and is mired in bureaucratic procedure. The increase in online digitization of natural history collections has now led to a surge in the number new studies on the uses of machine learning. These repositories of species occurrences are now equipped with advances that allow for the identification of rare species. The increase in attention devoted to estimating the scope and severity of the threats that lead to the decline of such species will increase our ability to mitigate these threats and reverse the declines, overcoming a current barrier to the recovery of many threatened plant species. Thus far, collected specimens have been used to fill gaps in systematics, range extent, and past genetic diversity. We find that they also offer material with which it is possible to foster species recovery, ecosystem restoration, and de-extinction, and these elements should be used in conjunction with machine learning and citizen science initiatives to mobilize as large a force as possible to counter current extinction trends.

Understanding the Lost: Reconstruction of the Garden Design of Villa Peretti Montalto (Rome, Italy) for Urban Valorization.

Urbanization and urban regeneration can significantly impact cultural heritage, but a greater knowledge of the past natural and historical features is needed to value the past and understand the present. The lost Villa Peretti Montalto in Rome, once located in the area that corresponds to the current front side of Termini station, deserves great attention due to its cultural value. This work aimed to provide a floristic and functional reconstruction of the gardens of the villa during the XVI and XVII Centuries. From several bibliographic and iconographic sources, a critical analysis and interpretation of plant names was conducted. A list of 87 species and their location in the different garden sectors, during different periods with their specific uses, is provided. The arboreal design was made by classical species in the Roman context, like Cupressus sempervirens, Pinus pinea, Quercus ilex, and Ulmus glabra. In addition, ancient lost varieties of fruit trees (mainly Pyrus communis and Ficus carica) and several species of conservation interest were found. The knowledge of the ancient flora in historical gardens could be a key tool in urban greenery planning and touristic and cultural valorization.

Out-of-date datasets hamper conservation of species close to extinction.

International databases and data aggregators on species conservation status are powerful tools supporting the efforts of conservation biologists and practitioners in reducing the loss of biodiversity. However, out-of-date information and poor interoperability of databases can hamper conservation of highly threatened species or in extreme cases can result in their removal from conservation frameworks. Lack of common standards for database updates, slow update timing and incongruencies among datasets in terms of taxonomy, threats, conservation status and holding prevent proper conservation prioritization and actions. A simple survey to solve incongruencies between the BGCI PlantSearch Database and the IUCN Red List resulted in a change of status of 16 plant species, including the 'rehabilitation' of 12 species thought to be extinct.

Selecting the best candidates for resurrecting extinct-in-the-wild plants from herbaria.

Resurrecting extinct species is a fascinating and challenging idea for scientists and the general public. Whereas some theoretical progress has been made for animals, the resurrection of extinct plants (de-extinction sensu lato) is a relatively recently discussed topic. In this context, the term 'de-extinction' is used sensu lato to refer to the resurrection of 'extinct in the wild' species from seeds or tissues preserved in herbaria, as we acknowledge the current impossibility of knowing a priori whether a herbarium seed is alive and can germinate. In plants, this could be achieved by germinating or in vitro tissue-culturing old diaspores such as seeds or spores available in herbarium specimens. This paper reports the first list of plant de-extinction candidates based on the actual availability of seeds in herbarium specimens of globally extinct plants. We reviewed globally extinct seed plants using online resources and additional literature on national red lists, resulting in a list of 361 extinct taxa. We then proposed a method of prioritizing candidates for seed-plant de-extinction from diaspores found in herbarium specimens and complemented this with a phylogenetic approach to identify species that may maximize evolutionarily distinct features. Finally, combining data on seed storage behaviour and longevity, as well as specimen age in the novel 'best de-extinction candidate' score (DEXSCO), we identified 556 herbarium specimens belonging to 161 extinct species with available seeds. We expect that this list of de-extinction candidates and the novel approach to rank them will boost research efforts towards the first-ever plant de-extinction.

Seventeen 'extinct' plant species back to conservation attention in Europe.

Seventeen European endemic plant species were considered extinct, but improved taxonomic and distribution knowledge as well as ex situ collecting activities brought them out of the extinct status. These species have now been reported into a conservation framework that may promote legal protection and in situ and ex situ conservation.