Extinction risk of the endemic vascular flora of Kauai, Hawaii, based on IUCN assessments.

The International Union for Conservation of Nature's Red List of Threatened Species (IUCN Red List) is the world's most comprehensive information source on the global conservation status of species. Governmental agencies and conservation organizations increasingly rely on IUCN Red List assessments to develop conservation policies and priorities. Funding agencies use the assessments as evaluation criteria, and researchers use meta-analysis of red-list data to address fundamental and applied conservation science questions. However, the circa 143,000 IUCN assessments represent a fraction of the world's biodiversity and are biased in regional and organismal coverage. These biases may affect conservation priorities, funding, and uses of these data to understand global patterns. Isolated oceanic islands are characterized by high endemicity, but the unique biodiversity of many islands is experiencing high extinction rates. The archipelago of Hawaii has one of the highest levels of endemism of any floristic region; 90% of its 1367 native vascular plant taxa are classified as endemic. We used the IUCN's assessment of the complete single-island endemic (SIE) vascular plant flora of Kauai, Hawaii, to assess the proportion and drivers of decline of threatened plants in an oceanic island setting. We compared the IUCN assessments with federal, state, and other local assessments of Kauai species or taxa of conservation concern. Finally, we conducted a preliminary assessment for all 1044 native vascular plants of Hawaii based on IUCN criterion B by estimating area of occupancy, extent of occurrence, and number of locations to determine whether the pattern found for the SIE vascular flora of Kauai is comparable to the native vascular flora of the Hawaiian Islands. We compared our results with patterns observed for assessments of other floras. According to IUCN, 256 SIE vascular plant taxa are threatened with extinction and 5% are already extinct. This is the highest extinction risk reported for any flora to date. The preliminary assessment of the native vascular flora of Hawaii showed that 72% (753 taxa) is threatened. The flora of Hawaii may be one of the world's most threatened; thus, increased and novel conservation measures in the state and on other remote oceanic islands are urgently needed.

La Lista Roja de la Unión Internacional para la Conservación de la Naturaleza (Lista Roja UICN) es la fuente más completa a nivel mundial de información sobre el estado de conservación de las especies. Las agencias gubernamentales y las organizaciones para la conservación dependen cada vez más de las valoraciones en esta lista para desarrollar sus políticas y prioridades de conservación; también los organismos de financiamiento usan las valoraciones como criterios de evaluación y los investigadores aplican metaanálisis a los datos de la lista para abordar preguntas fundamentales y aplicadas a las ciencias de la conservación. Sin embargo, las casi 143,000 valoraciones de la UICN representan sólo una fracción de la biodiversidad mundial y están sesgadas en cuanto a la cobertura regional y de organismos. Estos sesgos pueden afectar a las prioridades de conservación, al financiamiento y al uso de estos datos para entender los patrones globales. Las islas oceánicas aisladas se caracterizan por un alto endemismo, aunque la biodiversidad única de muchas de estas islas está experimentando un índice elevado de extinciones. El archipiélago de Hawái tiene uno de los niveles más altos de endemismo de cualquier región florística con el 90% de los 1,367 taxones nativos de flora vascular clasificado como endémico. Usamos las valoraciones de la UICN para todas las plantas vasculares endémicas de una sola isla (ESI) en Kauai, Hawái, para evaluar la proporción y los impulsores de la declinación de plantas amenazadas en el entorno de una isla oceánica. Comparamos las valoraciones de la UICN con las federales, estatales y otras valoraciones locales de las especies o taxones de Kauai que son de importancia para la conservación. Por último, realizamos una valoración preliminar para las 1,044 especies de plantas vasculares nativas de Hawái con base en el criterio B de la UICN mediante la estimación del área de ocupación, la extensión de la ocurrencia y el número de localidades para determinar si el patrón hallado para la flora vascular ESI de Kauai es comparable con la flora vascular nativa de las islas hawaianas. Comparamos nuestros resultados con los patrones observados en las valoraciones de otras floras. De acuerdo con la UICN, el 95% de los taxones de plantas vasculares ESI de Kauai están amenazadas y el 5% ya se encuentra extinto. A la fecha, este es el riesgo de extinción más alto reportado para cualquier flora. La valoración preliminar de la flora vascular nativa de Hawái mostró que el 72% (753 taxones) se encuentra amenazado. La flora de Hawái puede ser una de las más amenazadas a nivel mundial; por lo tanto, se necesitan urgentemente medidas novedosas e incrementadas en el estado y en otras islas oceánicas remotas.

Schiedeawaiahuluensis (Caryophyllaceae), an enigmatic new species from Kaua'i, Hawaiian Islands and the first species discovered by a drone collection system.

During a survey by the National Tropical Botanical Garden drone team, an enigmatic Schiedea was observed in December 2021on steep, rocky cliff faces of the Waiahulu Valley in the Waimea Canyon of Kaua'i. Subsequently, another survey was conducted in March 2022 and, by use of a remotely controlled cutting device suspended below the drone, the first herbarium specimen was collected, as well as a seed collection of an undescribed cliff-dwelling species of Schiedea. Detailed study of the collections and plants grown at the University of California, Irvine greenhouse showed that it had enlarged, somewhat whitish sepals similar to those of cliff-dwelling S.attenuata (the sole species in sect. Leucocalyx), yet differed significantly from all other species in the genus. It also shares with S.attenuata a woody habit, hermaphroditic flowers, coloured nectar and styles 5 to 7 or 8. We describe it here as S.waiahuluensis given the only known localities are on the cliffs of this valley and place it in an enlarged sect. Leucocalyx. With the discovery of this new species, there are 36 species in this Hawaiian endemic genus.

Collecting critically endangered cliff plants using a drone-based sampling manipulator.

Kaua'i, an island within the Hawai'i archipelago, is home of a unique flora that contains 250 single-island endemic plant species. Threats have led to a significant population decrease where 97% of these plant species are now listed as endangered, critically endangered, or extinct. Vertical cliff habitats on Kaua'i work as refugia to protect plants from their stressors. However, this habitat makes conservation work particularly difficult, forcing scientists, and botanists to use risky and time-consuming methods such as abseiling to access remote plant populations. Here we present the Mamba, the first aerial system capable of sampling plants on cliffs. This system is operated by two pilots and consists of an actively controlled platform suspended by a long cable under a lifting drone. Eleven otherwise inaccessible samples from five critically endangered species were collected during the first field trials on Kaua'i Island. The samples are currently surviving in nurseries, demonstrating that the Mamba can be used to complete the conservation life cycle for organisms located in difficult areas, from location to collection, then cultivation and outplanting.