Harnessing the potential of integrated systematics for conservation of taxonomically complex, megadiverse plant groups.

The value of natural history collections for conservation science research is increasingly recognized, despite their well-documented limitations in terms of taxonomic, geographic, and temporal coverage. Specimen-based analyses are particularly important for tropical plant groups for which field observations are scarce and potentially unreliable due to high levels of diversity-amplifying identification challenges. Specimen databases curated by specialists are rich sources of authoritatively identified, georeferenced occurrence data, and such data are urgently needed for large genera. We compared entries in a monographic database for the large Neotropical genus Myrcia in 2007 and 2017. We classified and quantified differences in specimen records over this decade and determined the potential impact of these changes on conservation assessments. We distinguished misidentifications from changes due to taxonomic remodeling and considered the effects of adding specimens and georeferences. We calculated the potential impact of each change on estimates of extent of occurrence (EOO), the most frequently used metric in extinction-risk assessments of tropical plants. We examined whether particular specimen changes were associated with species for which changes in EOO over the decade were large enough to change their conservation category. Corrections to specimens previously misidentified or lacking georeferences were overrepresented in such species, whereas changes associated with taxonomic remodeling (lumping and splitting) were underrepresented. Among species present in both years, transitions to less threatened status outnumbered those to more threatened (8% vs 3%, respectively). Species previously deemed data deficient transitioned to threatened status more often than to not threatened (10% vs 7%, respectively). Conservation scientists risk reaching unreliable conclusions if they use specimen databases that are not actively curated to reflect changing knowledge.

Empleo del Potencial de la Sistemática Integrada para la Conservación de Grupos Botánicos Complejos y Megadiversos Resumen Cada vez se reconoce más el valor que tienen las colecciones de historia natural para la investigación dentro de la ciencia de la conservación, a pesar de las limitaciones en la documentación adecuada de la cobertura taxonómica, geográfica y temporal. Los análisis con base en especímenes son de particular importancia en los grupos de plantas tropicales, para los cuales las observaciones en el campo son escasas y potencialmente de poca confianza debido la gran cantidad de retos de identificación que amplifican la diversidad. Las bases de datos de especímenes que son curadas por especialistas son fuentes abundantes de datos identificados autoritativamente y de distribución georeferenciada, por lo que es urgente la necesidad de dichos datos para géneros extensos. Comparamos las entradas en una base de datos monográfica para el género neotropical extenso Myrcia en 2007 y en 2017. Clasificamos y cuantificamos las diferencias en los registros de especímenes durante esta década y determinamos el impacto potencial de estos cambios sobre las evaluaciones de conservación. Separamos las identificaciones erróneas de los cambios causados por la remodelación taxonómica y consideramos los efectos de la adición de especímenes y de georeferencias. Calculamos el impacto potencial de cada cambio sobre las estimaciones de la extensión de la distribución (EOO, en inglés), la medida que se utiliza con mayor frecuencia en las valoraciones del riesgo de extinción de las plantas tropicales. Examinamos si los cambios en un espécimen particular estuvieron asociados con especies para las cuales los cambios en la EOO durante la década fueron lo suficientemente amplios para cambiarles la categoría de conservación. Las correcciones hechas a especímenes previamente mal identificados o carentes de georeferencias estuvieron sobre-representadas en dichas especies, mientras que los cambios asociados con la remodelación taxonómica (agrupamiento y separación) estuvieron sub-representados. Entre las especies presentes en ambos años, las transiciones hacia un estado de conservación con menor amenaza superaron en cantidad a aquellas hacia un estado de mayor amenaza (8% vs 3%, respectivamente). Las especies que con anterioridad se clasificaban como deficientes de datos tuvieron más transiciones hacia el estado de amenazadas que hacia el estado de no amenazadas (10% vs 7%, respectivamente). Los científicos de la conservación corren el riesgo de llegar a conclusiones poco confiables si utilizan bases de datos de especímenes que no sean actualizadas para reflejar el conocimiento cambiante.

Quantifying progress toward a conservation assessment for all plants.

The Global Strategy for Plant Conservation (GSPC) set an ambitious target to achieve a conservation assessment for all known plant species by 2020. We consolidated digitally available plant conservation assessments and reconciled their scientific names and assessment status to predefined standards to provide a quantitative measure of progress toward this target. The 241,919 plant conservation assessments generated represent 111,824 accepted land plant species (vascular plants and bryophytes, not algae). At least 73,081 and up to 90,321 species have been assessed at the global scale, representing 21-26% of known plant species. Of these plant species, at least 27,148 and up to 32,542 are threatened. Eighty plant families, including some of the largest, such as Asteraceae, Orchidaceae, and Rubiaceae, are underassessed and should be the focus of assessment effort if the GSPC target is to be met by 2020. Our data set is accessible online (ThreatSearch) and is a baseline that can be used to directly support other GSPC targets and plant conservation action. Although around one-quarter of a million plant assessments have been compiled, the majority of plants are still unassessed. The challenge now is to build on this progress and redouble efforts to document conservation status of unassessed plants to better inform conservation decisions and conserve the most threatened species.

The sampled Red List Index for plants, phase II: ground-truthing specimen-based conservation assessments.

The IUCN Sampled Red List Index (SRLI) is a policy response by biodiversity scientists to the need to estimate trends in extinction risk of the world's diminishing biological diversity. Assessments of plant species for the SRLI project rely predominantly on herbarium specimen data from natural history collections, in the overwhelming absence of accurate population data or detailed distribution maps for the vast majority of plant species. This creates difficulties in re-assessing these species so as to measure genuine changes in conservation status, which must be observed under the same Red List criteria in order to be distinguished from an increase in the knowledge available for that species, and thus re-calculate the SRLI. However, the same specimen data identify precise localities where threatened species have previously been collected and can be used to model species ranges and to target fieldwork in order to test specimen-based range estimates and collect population data for SRLI plant species. Here, we outline a strategy for prioritizing fieldwork efforts in order to apply a wider range of IUCN Red List criteria to assessments of plant species, or any taxa with detailed locality or natural history specimen data, to produce a more robust estimation of the SRLI.