ONAbout four decades ago, the late botanist Walter Scott trudged up a hill that was designated for mining and plucked a few yellow flowers from the rocky slope. He took the plants home and kept them in well-drained wooden bowls to save them from extinction. Scott’s forethought Hieracium hethlandiae (F. Hanb.) Pugsley, A hawkweed, whose star flowers might be mistaken for dandelions by the untrained eye, apparently went unnoticed by the broader botany community.
When the hillside habitat gave way to a street H. hethlandiae has been declared extinct by the UK’s National Biodiversity Network and in some scientific reports. But the plant is not extinct very much. Though Scott’s attempts to grow them back in the wild failed, the nonprofit Shetland Amenity Trust’s horticultural unit, to which he had donated some plants, succeeded in 2015, according to Paul Harvey, the organization’s natural heritage project manager. The plants have since developed into a second generation in their new home – a quarry with a geology similar to their home. Although they are still considered extinct in official records, “they seem fine here so far,” wrote Harvey in an email to The scientist.
Hieracium hethlandiae is a species of hawkweed native to the Shetland Islands. Although the species was officially considered extinct since its habitat was destroyed 40 years ago, it survived in plant collections and was reintroduced to its rocky home in 2015.
This week, H. hethlandiae joins more than a dozen other plants officially listed as extinct on national red lists, studies, and other reports but apparently still alive and – more or less – good. In a study published March 8 in Natural plants, The researchers tracked the true status of 36 officially extinct seed plant species that are endemic to Europe through a network of scientists across the continent. Thanks to rediscoveries, taxonomic revisions, and survival in botanical gardens, the authors recommend delisting 17 of them.
“Obviously it’s fantastic news [when] Plants are not extinct. But . . . They are still critically endangered, ”notes Rafaël Govaerts, botanist at the Royal Botanic Gardens in Kew, UK, who was not involved in the study. However, more research needs to be done on the survival of these plants, he adds. “There are still many unanswered questions about it.”
The new research began on the suspicion that some extinct seed plant records published in the scientific literature and used in a global analysis by Govaerts and colleagues for 2019 were inaccurate. Giulia Albani Rocchetti, a plant biologist and PhD student at the University of Roma Tre in Rome, and her colleagues set out to check the status of European species with local researchers in different countries, suggesting that they might have updates on the taxa. That endeavor was inspired in part by a 2020 report, for which researchers did the same to review the status of North American plants and questioned the reported extinctions of 14 species.
Based on a list of 36 officially extinct species compiled from National Red Lists, Govaerts’ study, and other reports, Rocchetti and colleagues contacted seed banks and botanical gardens to look for evidence that these species were still alive. They also checked records in public databases such as the Global Biodiversity Information Facility (GBIF). Notably, they learned that four officially extinct species had reappeared in the wild, such as: Ligusticum albanicum Jávorska, a member of the celery family that had been rediscovered in the Albanian mountains but was classified as extinct in Govaerts’ study.
For seven suspected extinct species, taxonomists now regard them as synonyms of living species, according to the team. For example the thistle Centaurea saxatilis (K. Koch) BD Jacks. was also believed to be extinct but is now recognized as the same as C. raphanina Sm. Which is widespread in Greece. Three other species have been misidentified in the past, including Nolletia chrysocomoides (Desf.) Cass. in Spain, which should be grouped with Galatella malacitana Blanca, Gavira & Suár.-Sant. Such taxonomic kerfuffles are not uncommon, says Rocchetti. Since individuals vary with a species, “they may be misidentified depending on the original sample of that species. Or after that [phylogenetic] Studies show that this species is actually a different species. “
Another extinct plant Filago Neglecta (Soy-Will.) DC., Which belongs to the genus of cotton roses, is said to have died out in western European countries at the beginning of the 20th century. However, the team discovered a French herbarium that may still contain viable seeds. Two other species live in botanical gardens, including H. hethlandiae in the horticultural division of the Shetland Amenity Trust and Armeria arched Welw. ex Boiss. & Reut., A “Sea Pink” species native to Portugal. Surprisingly, this one was preserved in botanical gardens in Utrecht. “And they didn’t even know that the species was actually extinct in Portugal,” says botanist and conservation biologist Thomas Abeli from the University of Roma Tre, who co-authored the study.
For Rocchetti and Abeli, the results show that the way species are defined can affect absorbance estimates, leading to a slight overestimation. Overall, however, these errors are likely to be offset by the fact that scientists also underestimate extinction because numerous species are likely to disappear before they are discovered, or because there is insufficient evidence to declare a species extinct even if it does , Says Abeli.
The results also underscore the value of local knowledge in improving the accuracy of absorbance ratings and how out of date some national Red Lists and similar absorbance ratings are, say the two authors. Ideally, there should be better communication between those making these lists and the researchers in the field. Citizen scientists also play a role, Abeli adds, referring to reports on one of the rediscovered species. Astragalus nitidiflorus Jiménez Mun. & Pau, on the Citizen Science platform iNaturalist. “I think iNaturalist, Pl @ ntnet, GBIF – all these big repositories where [lay] People can upload photos – this helps find species that are considered extinct or have not been seen in a long time, ”he says.
The extinct Ranunculus mutinensis Pignatti
© Herbarium Centrale Italicum, Museo di Storia Naturale, Sistema Museale di Ateneo, Università degli Studi di Firenze. Permission to use this photo is given to Thomas Abeli, Dipartimento di Scienze, Università Roma Tre
As for the global Red List curated by the International Union for Conservation of Nature (IUCN) – by far the most comprehensive and widely used catalog of conservation statuses – many species in Abeli’s study have not yet been assessed there by David Allen, the regional one Commissioner for the Assessment of Biodiversity of the IUCN Red List. The organization does not have the resources to record all extinct or critically endangered taxa. However, she recently received a call for tenders from the European Commission to review a number of taxonomic groups, including some in the new study. A re-evaluation of A. nitidiflorus“When we found out that the species was indeed rediscovered in the wild,” added Allen.
All of them agreed, Leopoldo Medina, a botanist who manages the vascular plant collection at Real Jardín Botánico, part of the Spanish National Research Council, that the results underscore the importance of trained plant taxonomists in creating extinctionists. “Comprehensive analyzes can fail in many cases if taxa are treated without their knowledge,” Medina wrote in an email The scientist. Further field work is also required; Although temperate regions in western countries have been relatively well studied, “we are far from knowing the diversity,” he adds.
The new findings are no surprise to Govaerts or Medina. Some previous research by Medina’s colleagues has already included the problem of misidentification N. chrysocomoides, and together they reported the rediscovery of some species in Spain. Govaerts’ global analysis also included some of the rediscoveries, but not new, unpublished local knowledge, such as the fact that H. hethlandiae was reintroduced. “I fully agree that unpublished data and local knowledge can be added to our list, but that was not the intent of our paper,” he says.
Comparing the lists in Govaerts’ article and the new study reveals a handful of other inconsistencies. For example, two are missing from Rocchetti and Abeli’s list of extinct plants Bromus Grass species listed as extinct in the wild in Govaerts’ study, while their list of non-extinct taxa does not include the white-leaved Gibraltar stock Silene tomentosa Otth, which was rediscovered in 1994. Abeli notes that his list is only intended to cover species that are considered extinct but whose delisting has not yet been recognized in official lists. Ultimately, both studies come to a similar conclusion, with about half of the species considered extinct not being completely lost. By and large, “Rediscover numbers [remain very] low in relation to the extinction rates, ”adds Medina, partly because the researchers did not know the exact extent of the extinction before Linn before plants were taxonomically categorized.
Govaerts warns that the taxonomy is constantly evolving and that recent revisions may not have been set in stone. It is also not clear whether the herbarium seeds – or even the whole plant specimens – lead to self-sustaining plant populations.
He adds that delisting is always good news. Beyond the obvious, the problem with declaring extinction is that species then lose conservation and legal protection attention. Studies like this show that absorbance lists are not necessarily permanent endpoints, but rather flowing labels. “Extinct means we haven’t found it in a hundred years, but you can turn another corner and there it is.”
T. Abeli et al., “Seventeen ‘extinct’ plant species that are back under nature protection in Europe”, Nat plants, doi: 10.1038 / s41477-021-00878-1, 2021.