Arthur Hugh Garfit Alston

Scleria is a pantropical genus of annual and perennial herbs and the sixth largest genus in the Cyperaceae family with around 261 species. In this study, we produced preliminary extinction risk assessments for the ~30% of Scleria species that do not yet have a global Red List assessment and followed the Evolutionarily Distinct and Globally Endangered (EDGE2) and Ecologically Distinct and Globally Endangered (EoDGE) protocols to identify evolutionary and ecologically unique Scleria species at greatest risk of extinction and hotspots of rare and endangered species. Our results indicate that 38 of the 78 Scleria species not yet included in the Red List, and 26% of species in the genus, are potentially threatened with extinction. The risk of extinction is not equally distributed across the phylogeny, and the Afrotropics and the Neotropics accumulate most threatened species. Eleven ecoregions mostly from four African (Madagascar, D.R. Congo, Zambia and Tanzania) and two South American (Brazil, Venezuela) countries accumulate almost half of Scleria species and stand out in terms of their sum of EDGE2 scores. Phylogenetic and functional distinctiveness metrics were largely uncorrelated, and the EcoDGE metric mostly points towards South American countries as reservoirs of ecologically distinctive and endangered species: Brazil, Venezuela, Bolivia, Peru, Colombia, Guyana and Dominican Republic. Recent methodological advances in the identification of species at-risk of extinction and the novel EDGE2 framework emerge as powerful tools to identify conservation priorities.

Karst formations are distinguished by their high levels of species diversity and endemism, including ferns and lycophytes. However, the existing data on plant community composition in karst formations remains deficient. Addressing these knowledge gaps is imperative, given the current accelerated rates of species loss, to enhance efforts to conserve biodiversity in these habitats. This study documents and explains patterns of fern and lycophyte species diversity within karst landscapes (KL) and non-karst landscapes (NKL) in the Philippines. Our comprehensive analysis involved aggregating 19,529 occurrence points encompassing 1,024 fern and lycophyte species sourced from field expeditions, voucher records from local herbaria, and online databases. Indices for species richness, weighted endemism, and corrected weighted endemism were then computed across KL and NKL areas to describe spatial diversity and identify fern and lycophyte hotspot areas. Gap analyses were also performed to determine if established protected areas (PAs) were sufficient to cover the identified fern and lycophyte diversity hotspots. Principal Component Analysis (PCA) was conducted to determine potential ecological drivers of distribution between KL and NKL areas. The findings reveal that most fern and lycophyte species were recorded to occur in NKL areas, with 995 (97.16%) species identified, while 676 (66.02%) species were documented to occur in KLs, including 29 (2.83%) exclusive to karsts. Identified hotspots for NKL are within mountain ecosystems, which are already under existing legal protection. In contrast, KLs have five areas identified as congruent hotspots but considered gap areas due to their exclusion from current PA boundaries. Existing PAs thus provide less protection to karst habitats and their associated floras. PCA did not reveal any significant environmental predictors, suggesting separation of KL and NKL species distributions, possibly due to lack of high-resolution environment data available for karsts. To facilitate the conservation of fern and lycophyte species in karsts, we propose installing and expanding existing PA boundaries, along with conducting more focused surveys in karst regions to better understand their ecological dynamics.

AbstractPremiseBiotic disjunctions have attracted scientific attention for the past 200 years. Despite being represented in many familiar plants (such as bald cypress, flowering dogwood, sweetgum, partridgeberry, etc.), the eastern North American (ENA)–Mexican (M) disjunction remains poorly understood. Major outstanding questions include the divergence times of taxa exhibiting the disjunction and environmental/geological processes that may underlie the disjunction. Symphyotrichum Nees (Asteraceae), one of the most diverse genera in the eastern USA, displays several examples of disjunct ENA–M taxa.MethodsWe generated target capture data using the Angiosperms353 baitset and generated the first well‐sampled phylogenomic hypothesis for Symphyotrichum and its close relatives. Focusing on S. subgenus Virgulus, we used MCMCTREE to perform divergence time estimation and the R package BioGeoBEARS to infer ancestral regions and biogeographic transitions between North America and Mexico. Finally, we used the ancestral niche reconstruction method Utremi to test for a role of historical aridification in generating the disjunction.ResultsOur molecular data suggest a recent radiation of Symphyotrichum at the Plio‐Pleistocene boundary (~2.5 mya), with early connections to Mexico in ancestral lineages that closed off shortly after and were followed by vicariance across this region. Except for some present‐day broadly distributed species, there is a complete lack of movement between ENA and M after ~0.5 mya.ConclusionsA reconstructed disjunct distribution of suitable habitat in Pleistocene climatic models corroborates results from biogeographic modeling and confirms glacial cycles are more likely to be associated with the breakup of ENA–M biogeographic connections.

En Santander, Colombia, asociado al valle del Magdalena Medio se presentan serranías con remanentes boscosos que contrastan con las zonas deforestadas de las partes bajas. Presentamos una serie (90 especímenes de 48 especies) de la Serranía de La Paz, Betulia, catalogada en la Colección de Ornitología del Museo de Historia Natural de la Universidad Industrial de Santander (UIS-AV) y que proviene principalmente de una expedición en 2023 con el objetivo de estudiar su avifauna a partir de especímenes. La composición de especies de esta serie se comparó con la de otras series de UIS-AV recolectadas recientemente en el Magdalena Medio, y con una serie recolectada en la misma serranía en 1956 cuya información fue obtenida en el GBIF. Nuestra serie de la Serranía de La Paz comparte más especies con un área de bosque continuo en Bolívar que con fragmentos de bosque en Santander. Aunque varias especies de la Serranía de La Paz se registran en otros sitios del Magdalena Medio, nuestra serie incluye a Cotinga nattererii, Trogon rufus y Trogon caligatus que son especies con pocos especímenes para Santander que fueron recolectados hace más de 70 años, además de Euphonia concinna que representa un registro novedoso para el departamento. El 90 % de las especies recolectadas en 1956 están en UIS-AV o se registraron en 2023, pero Psarocolius wagleri, Cacicus cela y Falco sparverius, estuvieron ausentes. La Serranía de La Paz tiene especies de aves características de bosques del Magdalena Medio y puede ser un sitio apropiado para conservarlas.

The family Onocleaceae represents a small family of terrestrial ferns, with four genera and around five species. It has a circumboreal to north temperate distribution, and exhibits a disjunct distribution between Eurasia and North America, including Mexico. Historically, the taxonomy and classification of this family has been subject to debate and contention among scholars, leading to contradictory classifications and disagreements on the number of genera and species within the family. Furthermore, due to this disjunct intercontinental distribution and the lack of detailed study across its wide range, this family merits further study to clarify its distributional pattern. Maximum likelihood and Bayesian phylogenetic reconstructions were based on a concatenated sequence dataset for 17 plastid loci and one nuclear locus, which were generated from 106 ingroup and six outgroup taxa from three families. Phylogenetic analyses support that Onocleaceae is composed of four main clades, and Pentarhizidium was recovered as the first branching lineages in Onocleaceae. Molecular dating and ancestral area reconstruction analyses suggest that the stem group of Onocleaceae originated in Late Cretaceous, with subsequent diversification and establishment of the genera Matteuccia, Onoclea, Onocleopsis, and Pentarhizidium during the Paleogene and Neogene. The ancestors of Matteuccia, Onoclea, and Onocleopsis could have migrated to North America via the Beringian land bridge or North Atlantic land bridge which suggests that the diversification of Matteuccia + Onoclea + Onocleopsis closely aligns with the Paleocene-Eocene Thermal Maximum (PETM). In addition, these results suggest that Onocleaceae species diversity peaks during the late Neogene to Quaternary. Studies such as this enhance our understanding of the mechanisms and climatic conditions shaping disjunct distribution in ferns and lycophytes of eastern Asia, North America, and Mexico and contribute to a growing body of evidence from other taxa, to advance our understanding of the origins and migration of plants across continents.

The Southern Islands Vascular Flora (SIVFLORA) dataset is a globally significant, open-access resource that compiles essential biodiversity data on vascular plants from islands across the Southern Ocean. The SIVFLORA dataset was generated through five steps: study area delimitation, compiling the dataset, validating and harmonizing taxonomy, structuring dataset attributes, and establishing file format and open access. Covering major taxonomic divisions, SIVFLORA offers a comprehensive overview of plant occurrences, comprising 14,589 records representing 886 species, 95 families, and 42 orders. This dataset documents that 58.62% of the taxa are native, 9.61% are endemic, and 31.77% are alien species. The Falkland/Malvinas Archipelago, the most species-rich, contrast sharply with less diverse islands like the South Orkney Archipelago. SIVFLORA serves as a taxonomically harmonized, interoperable resource for investigating plant diversity patterns, ecosystem responses to climate change in extreme environments, island biogeography, endemism, and the effects of anthropogenic pressures on Southern Ocean flora.

Without appropriate and ongoing management interventions, weeds will continue to economically and environmentally disadvantage agricultural and natural ecosystems. For these management strategies to have long‐term sustained success, they need to carefully consider the biological aspects of the targeted weed. These strategies will also need to consider potential adaptations evolved by the targeted weed in response to a range of selection pressures imposed by anthropogenetic factors, climate change, changing environmental conditions, and inappropriate or unsuccessful management regimes. One group of weeds that has been observed to readily adapt to a wide range of conditions and has shown considerable challenges in their management is invasive grasses. Adding to these challenges is that several invasive grasses have also developed resistance to a range of herbicide modes of action, which, to date, has been one of the most commonly used methods of control. To address these challenges, this review explores the biology and ecology of the globally invasive annuals Echinochloa crus‐galli (Barnyard grass) and Panicum capillare (Witchgrass), and the perennial Sorghum halepense (Johnson grass) to identify (i) the most suitable management options for their control and (ii) potential research gaps that may assist in the future management direction of these species. Based on the findings of this review, it is clear that an integrated management approach that targets different aspects of the plant's biology, in combination with early detection and treatment and ongoing surveillance, is necessary for the long‐term control of these species. Although a combination of methods appears promising, further investigation still is required to evaluate their efficiency and long‐term success in a changing environment, all of which are further discussed within this review.

The flowering phenology of many tropical mountain forest tree species remains poorly understood, including flowering synchrony and its drivers across neotropical ecosystems. We obtained herbarium records for 427 tree species from a long-term monitoring transect on the northwestern Ecuadorian Andes, sourced from the Global Biodiversity Information Facility and the Herbario Nacional del Ecuador. Using machine learning algorithms, we identified flowering phenophases from digitized specimen labels and applied circular statistics to build phenological calendars across six climatic regions within the neotropics. We found 47 939 herbarium records, of which 14 938 were classified as flowering by Random Forest Models. We constructed phenological calendars for six regions and 86 species with at least 20 flowering records. Phenological patterns varied considerably across regions, among species within regions, and within species across regions. There was limited interannual synchronicity in flowering patterns within regions primarily driven by bimodal species whose flowering peaks coincided with irradiance peaks. The predominantly high variability of phenological patterns among species and within species likely confers adaptative advantages by reducing interspecific competition during reproductive periods and promoting species coexistence in highly diverse regions with little or no seasonality.

Cold tolerance strategies in plants vary from structural to biochemical permitting many plants to survive and grow on sites that experience freezing conditions intermittently. Although tree ferns occur predominantly across the tropics, they also occur in temperate zones and occasionally in areas that experience sub‐zero temperatures, and how these large ferns survive freezing conditions is unknown. Many temperate tree fern taxa are marcescent – retaining whorls of dead fronds encircling the upper trunk – or develop short or prostrate trunks, possibly to insulate against frost damage to their trunks and growing crowns. We asked the following questions: 1) do global growth patterns and traits of tree ferns respond to freezing conditions associated with latitude and elevation, 2) do growth patterns of tree ferns in New Zealand vary along a temperature‐related gradient, and 3) do marcescent tree fern skirts insulate the growing crown from sub‐zero temperatures? To establish what morphological adaptations permitted the Cyatheales to occur in biomes that experience intermittent sub‐zero temperatures and frost, we 1) reviewed the global distributions of these structural and morphological traits within the tree ferns (Cyatheales); 2) assessed the patterns of tree fern marcescence, and other traits potentially associated with cold tolerance (no trunk, prostrate, short‐trunked) of nine taxa of the Cyatheales along environmental gradients across New Zealand; and 3) conducted a field experiment to assess the thermal insulation properties of tree fern marcescent skirts. We identified significant trends among growth forms, marcescence, and environmental gradients consistent with our hypothesis that these are adaptations to tolerate cold. Our field experiments provide quantitative evidence that marcescent skirts have a strong insulating effect on tree fern trunks. The Cyatheales have evolved several strategies to protect the pith cores of their trunks from extreme cold temperatures in temperate forests allowing them to capture niche space in environments beyond the tropics.

The Arecaceae family (palms) holds global significance for its economic and ecological roles. Borneo is known as a center of endemic plant species but faces threats from human activities, including those affecting palms. This study aims to update the distribution and conservation status of endemic Bornean palms, identify potential conservation priority areas, and conduct a gap analysis to inform conservation strategies. The methodology involved comprehensive data collection, along with spatial and statistical analysis for conservation assessment and prioritization. Despite challenges like limited data on palm distribution in Indonesia, the study provides critical insights for developing targeted conservation strategies, particularly for conservation priority areas outside protected areas. The study identified 210 endemic Bornean palms, including 16 genera and 111 local endemics, with Malaysia exhibiting the highest species richness. Preliminary global assessment categorized 147 species as threatened palms, with 51 Critically Endangered (CR), 65 Endangered (EN), and 31 Vulnerable (VU). Meanwhile, 63 species were recognized as Least Concern (LC) and Near Threatened (NT). Furthermore, we conducted a hotspot analysis to identify key areas for conservation efforts. This analysis identified 32 grids (covering 12,378.93 km2), representing 10 % of the total identified Conservation Priority Areas (CPA), and 45 grids (covering 104,257.3 km2), representing 20 %. The larger area encompassed by the 20 % CPA highlights broader landscape-level priorities, emphasizing the importance of scaling conservation efforts to address habitat connectivity and ecological resilience. These areas spanned all regions, but a higher percentage was found in Malaysia at 10 % and 20 % sensitivity levels. These findings provide important guidance for targeted conservation actions and support further discussions on the future conservation of endemic Bornean palms.