Multiple introductions, polyploidy and mixed reproductive strategies are linked to genetic diversity and structure in the most widespread invasive plant across Southern Ocean archipelagos

This work received support from the Swiss Polar Institute and Ferring Pharmaceuticals through the Antarctic Circumnavigation Expedition (“ACE”). Additional fi- nancial and logistical support was provided by the South African National Research Foundation (NRF) and by the South African National Antarctic Programme (SANAP). MM and CH were also supported by the National Research Foundation (grant 89967). We thank Tasmanian Parks and Wildlife Service for granting ac- cess and collection permits for Macquarie Island and the Australian Antarctic Program for logistical support. We thank Institut polaire français Paul- Émile Victor for logistical support for sampling on Iles Kerguelen and Ile de la Possession. We thank wintering staff for sam- ple collection on Ile de la Possession. We thank the Department of Conservation for granting access and collection permits for the New Zealand islands. We thank Heritage Expeditions for providing logis- tics and voyage support. Collections were undertaken on the ACE expedition under permits granted to the expedition and its research- ers. Collections at the Prince Edward Islands, and at the Tristan da Cunha and Gough islands were permitted through the South African National Antarctic Program, notably via the Prince Edward Islands Management Committee for the former and the Tristan da Cunha Conservation Department for the latter.Biological invasions in remote areas that experience low human activity provide unique opportunities to elucidate processes responsible for invasion success. Here we study the most widespread invasive plant species across the isolated islands of the Southern Ocean, the annual bluegrass, Poa annua. To analyse geographical variation in genome size, genetic diversity and reproductive strategies, we sampled all major sub-Antarctic archipelagos in this region and generated microsatellite data for 470 individual plants representing 31 populations. We also estimated genome sizes for a subset of individuals using flow cytometry. Occasional events of island colonization are expected to result in high genetic structure among islands, overall low genetic diversity and increased self-fertilization, but we show that this is not the case for P. annua. Microsatellite data indicated low population genetic structure and lack of isolation by distance among the sub-Antarctic archipelagos we sampled, but high population structure within each archipelago. We identified high levels of genetic diversity, low clonality and low selfing rates in sub-Antarctic P. annua populations (contrary to rates typical of continental populations). In turn, estimates of selfing declined in populations as genetic diversity increased. Additionally, we found that most P. annua individuals are probably tetraploid and that only slight variation exists in genome size across the Southern Ocean. Our findings suggest multiple independent introductions of P. annua into the sub-Antarctic, which promoted the establishment of genetically diverse populations. Despite multiple introductions, the adoption of convergent reproductive strategies (outcrossing) happened independently in each major archipelago. The combination of polyploidy and a mixed reproductive strategy probably benefited P. annua in the Southern Ocean by increasing genetic diversity and its ability to cope with the novel environmental conditions.National Research Foundation 89967Antarctic Circumnavigation Expedition “ACE”South African National Research Foundation (NRF)South African National Antarctic Programme (SANAP

Ancient vicariance and climate-driven extinction explain continental-wide disjunctions in Africa: the case of the Rand Flora genus Canarina (Campanulaceae)

20 p., gráf., mapas, tablas -- Post-print del artículo publicado en Molecular Ecology. Versión revisada y corregida.Transoceanic distributions have attracted the interest of scientists for centuries. Less attention has been paid to the evolutionary origins of ‘continent-wide’ disjunctions, in which related taxa are distributed across isolated regions within the same continent. A prime example is the ‘Rand Flora’ pattern, which shows sister taxa disjunctly distributed in the continental margins of Africa. Here, we explore the evolutionary origins of this pattern using the genus Canarina, with three species: C. canariensis, associated with the Canarian laurisilva, and C. eminii and C. abyssinica, endemic to the Afromontane region in East Africa, as case study. We infer phylogenetic relationships, divergence times and the history of migration events within Canarina using Bayesian inference on a large sample of chloroplast and nuclear sequences. Ecological niche modelling was employed to infer the climatic niche of Canarina through time. Dating was performed with a novel nested approach to solve the problem of using deep time calibration points within a molecular dataset comprising both above-species and population-level sampling. Results show C. abyssinica as sister to a clade formed by disjunct C. eminii and C. canariensis. Miocene divergences were inferred among species, whereas infraspecific divergences fell within the Pleistocene–Holocene periods. Although C. eminii and C. canariensis showed a strong genetic geographic structure, among-population divergences were older in the former than in the latter. Our results suggest that Canarina originated in East Africa and later migrated across North Africa, with vicariance and aridification-driven extinction explaining the 7000 km/7 million year divergence between the Canarian and East African endemics.This work was funded by the Spanish Ministerio de Economía y Competitividad (Projects CGL2006-09696, CGL2009-1332-C03-01, CGL2012-40129-C02-01) the JAE-Doc programme (CSIC/FSE) to MA, and a PhD research grant (BES-2010-037261) to MM. LP was funded by a research contract under CGL2012-40129-C02-01.Peer reviewe

Biogeography Meets Niche Modeling: Inferring the Role of Deep Time Climate Change When Data Is Limited

Biogeography Meets Niche Modeling: Inferring the Role of Deep Time Climate Change When Data Is Limited. Geographic range shifts are one major organism response to climate change, especially if the rate of climate change is higher than that of species adaptation. Ecological niche models (ENM) and biogeographic inferences are often used in estimating the effects of climatic oscillations on species range dynamics. ENMs can be used to track climatic suitable areas over time but have often been limited to shallow timescales; biogeographic inference can reach greater evolutionary depth, but often lacks spatial resolution. This study presents a simple approach that treats them as independent and complementary sources of evidence, which, when used in partnership, can be employed to reconstruct geographic range shifts over deep evolutionary timescales. For testing this, we chose two extreme African disjunctions: Camptoloma (Scrophulariaceae) and Canarina (Campanulaceae), each comprising of three species disjunctly distributed in Macaronesia and eastern/southern Africa. Using inferred ancestral ranges in tandem with preindustrial and paleoclimate ENM hindcastings, we show that the disjunct pattern was the result of fragmentation and extinction events linked to Neogene aridification cycles. Our results highlight the importance of considering temporal resolution when building ENMs for rare endemics with small population sizes and restricted climatic tolerances such as Camptoloma, for which models built on averaged monthly variables were more informative than those based on annual bioclimatic variables. Additionally, we show that biogeographic information can be used as truncation threshold criteria for building ENMs in the distant past. Our approach is suitable when there is sparse sampling on species occurrences and associated patterns of genetic variation, such as in the case of ancient endemics with widely disjunct distributions as a result of climate change

Editorial: Overcoming the Global Climate Crisis: Solutions to Minimize the Loss of Mediterranean Plants

Editorial on the Research Topic Overcoming the Global Climate Crisis: Solutions to Minimize the Loss of Mediterranean PlantsMediterranean-climate regions are home to significant levels of plant diversity and endemism that are challenged by the threats of the modern world: habitat loss and fragmentation, high human population growth, and overexploitation of natural resources. Because of the fast rate of changes occurring in its ecosystems, many plants are threatened, and the trend is to worsen throughout the century (Muñoz-Rodríguez et al., 2016; Habel et al., 2019; Abeli et al., 2021). By 2100, this area will experience the highest biodiversity loss of all terrestrial biomes (Sala et al., 2000). In this context, and with the Damocles sword of climate change, it is urgent to explore new perspectives to prevent and reduce the loss of Mediterranean plantsinfo:eu-repo/semantics/publishedVersio

Rare and widespread: integrating Bayesian MCMC approaches, Sanger sequencing and Hyb-Seq phylogenomics to reconstruct the origin of the enigmatic Rand Flora genus Camptoloma

Premise Genera that are widespread, with geographically discontinuous distributions and represented by few species, are intriguing. Is their achieved disjunct distribution recent or ancient in origin? Why are they species-poor? The Rand Flora is a continental-scale pattern in which closely related species appear codistributed in isolated regions over the continental margins of Africa. Genus Camptoloma (Scrophulariaceae) is the most notable example, comprising three species isolated from each other on the northwest, eastern, and southwest Africa. Methods We employed Sanger sequencing of nuclear and plastid markers, together with genomic target sequencing of 2190 low-copy nuclear genes, to infer interspecies relationships and the position of Camptoloma within Scrophulariaceae by using supermatrix and multispecies-coalescent approaches. Lineage divergence times and ancestral ranges were inferred with Bayesian Markov chain Monte Carlo (MCMC) approaches. The population history was estimated with phylogeographic coalescent methods. Results Camptoloma rotundifolium, restricted to Southern Africa, was shown to be a sister species to the disjunct clade formed by C. canariense, endemic to the Canary Islands, and C. lyperiiflorum, distributed in the Horn of Africa–Southern Arabia. Camptoloma was inferred to be sister to the mostly South African tribes Teedieae and Buddlejeae. Stem divergence was dated in the Late Miocene, while the origin of the extant disjunction was inferred as Early Pliocene. Conclusions The current disjunct distribution of Camptoloma across Africa was likely the result of fragmentation and extinction and/or population bottlenecking events associated with historical aridification cycles during the Neogene; the pattern of species divergence, from south to north, is consistent with the “climatic refugia” Rand Flora hypothesis

iNaturalist: aplicaciones, oportunidades y aspectos a tener en cuenta en cuanto a su uso en botánica

Comunicación oral presentada en el XI Congreso de Biología de la Conservación de Plantas (SEBiCoP) celebrado del 17 al 21 de julio de 202

El Biomaratón de Flora Española: un evento de participación ciudadana para reconectar a la ciudadanía con la diversidad vegetal

Póster presentado en el XI Congreso de Biología de la Conservación de Plantas (SEBiCoP) celebrado del 17 al 21 de julio de 202

I Biomaratón de Flora Española: ciencia ciudadana para visibilizar la biodiversidad vegetal

[ES] Con objeto de fomentar el interés por la botánica, surgió la idea de organizar el I Biomaratón de Flora Española: un evento de ciencia ciudadana en el que personas de todo el país salieron a fotografiar el mayor número posible de plantas. Se realizó utilizando la plataforma de ciencia ciudadana iNaturalist, y se vertebró por medio de coordinadores en todas las comunidades autónomas y de alrededor de 100 instituciones, que dieron apoyo y divulgación al evento. Del 21 al 23 de mayo de 2021, más de 1.000 participantes registraron unas 25.000 observaciones de más de 2.500 especies, aproximadamente el 25% de las especies documentadas en España. Además, se organizaron actividades asociadas, como charlas, paseos botánicos, talleres de manejo de la plataforma, etc. Posteriormente se realizó un datablitz, centrado en la identificación de grupos de plantas poco conocidos, complicados y/o atractivos, y en compartir las experiencias de las actividades realizadas, fomentando así la interacción entre botánicos y ciudadanos. Este ha sido el mayor evento de ciencia ciudadana centrado en la botánica organizado en España. Queda demostrado que la acción conjunta de aficionados y profesionales puede ayudar a fomentar la pasión por la biodiversidad.[EN] With the intention of fostering the interest in botany in the society, the idea of organizing the 1st Bioblitz of Spanish Flora arose: a citizen science event in which people from all over the country went out to register as many species of plants as possible through photographs. The event was organized throughout the iNaturalist citizen science platform, and later supported by coordinators in all the Spanish Autonomous Communities and around 100 institutions that gave support and dissemination of the event. From May 21st to 23rd of 2021, more than 1,000 participants recorded about 25,000 observations of more than 2,500 species, approximately 25% of the species documented in Spain. In addition, numerous associated activities were organized, such as talks, botanical walks, workshops, etc. Subsequently, a datablitz was held, focused on the identification of little-known, complicated and/or attractive plant groups, and to share the experiences of the activities carried out, thus promoting interaction between botanists and citizens. To conclude, some of the experiences of the Bioblitz were presented. This is the largest botanical-focused citizen science event ever organized in Spain. It has been proven that the cooperative action of amateurs and professionals might help foster the passion for biodiversity.Motivación y objetivos Resultados del I Biomaratón Evento datablitz para comunicar a científicos y ciudadanos Ciencia ciudadana como motor de interés botánico II Biomaratón de Flora Española Agradecimiento

Resolviendo una incógnita biogeográfica, el caso de la Rand Flora afro-mediterránea.

Existe un enigmático patrón florístico que ha intrigado a científicos y naturalistas desde hace décadas. Consiste en una distribución de linajes de plantas emparentados que se encuentran distribuidos en regiones florísticas alrededor del continente africano, y separados por áreas de clima hostil. En biogeografía este tipo de distribuciones fragmentadas se conocen como disyunciones. Este patrón de distribución florística en forma de anillo, se conoce como Rand Flora. Dos hipótesis se han postulado para explicar este patrón: 1) Una serie de acontecimientos climáticos y geológicos habrían extirpado una flora ancestral de parte de su área de distribución, quedando así relegada a refugios alrededor de África. 2) Las disyunciones observadas son el resultado de recientes eventos de dispersión a larga distancia, con una posterior diversificación en las nuevas áreas. El objetivo del proyecto es entender los factores históricos que han configurado este patrón florístico. Se aborda el análisis a partir del estudio comparado de varios grupos de plantas que muestran dicha distribución, usando técnicas filogenéticas moleculares, datación y nuevos métodos biogeográficos. En el presente trabajo se hace una introducción al patrón conocido como Rand Flora. Se enumeran sugerentes ejemplos para interpretar las distribuciones geográficas. Se presentan los estudios de dos casos de especial relevancia, relacionados con dicho patrón; el caso Canarina y el caso Hypericum. Además se exponen y discuten los primeros resultados del proyecto

Lineage-specific climatic niche drives the tempo of vicariance in the Rand Flora

Aim: The disjunct distribution patterns of sister taxa can arise when previously continuous distribution ranges are fragmented by environmental changes such as major climatic events. Populations become isolated on either side of the newly established environmental barrier, and absence of gene flow promotes allopatric speciation, in a process that is known as ecological vicariance. If climate change altered the ancestral range gradually, such as along temporal temperature or moisture gradients, the age of divergence of disjunct species should be related to the lineage tolerance to climatic conditions. Here, we investigate this hypothesis using as a study model the African Rand Flora, a continental-scale floristic pattern that relates sister taxa distributed on either side of the Saharan Desert. Location: Africa, Macaronesia, Mediterranean Basin and the Middle East. Methods: We estimated the extant climatic tolerances of 14 Rand Flora lineages based on present occurrence data, and correlated the phylogenetic age of divergence between vicariant clades. We tested whether the tempo of the vicariance in the Rand Flora lineages was associated with the average values of their climatic niches in agreement with niche-driven divergence. We hindcasted species ranges using species distribution models combined with palaeoclimate simulations to infer the potential distribution of each lineage's ancestors. Results: We found a positive relationship between the lineage temperature niche and the age of the Rand Flora disjunction: lineages with subtropical affinities diverged first, whereas those with a higher tolerance to drier conditions (temperate or sub-xeric adaptations) exhibited younger disjunctions. The range reconstructions showed the existence of climatic corridors south of the Sahara in the wetter Late Miocene, which became interrupted during the mid-Pliocene warming event. Main conclusions: Our results suggest that climate change leading to the formation of the Sahara Desert drove Rand Flora lineages divergences along a temporal sequence that matched the climatic niche of species.Peer Reviewe