Browsing by Author "Convey, Peter"

Now showing 1 - 5 of 5
  • No Thumbnail Available
    Item
    Ancient diversification in extreme environments: exploring the historical biogeography of the Antarctic winged midge Parochlus steinenii (Diptera: Chironomidae)
    (2024) Maturana, Claudia S.; Mejias, Tamara Contador; Simoes, Felipe L.; Valladares, Moises A.; Vidal, Paula M.; Ganan, Melisa; Gonzalez-Wevar, Claudio A.; Poulin, Elie; Sands, Chester J.; Convey, Peter
    The terrestrial fauna of Antarctica consists of a limited number of species, notably insects, small crustaceans and other micro-invertebrates. Over long periods of evolutionary isolation, these organisms have developed varying degrees of tolerance to multifaceted environmental stresses. Recent molecular biogeographical research highlights the enduring persistence of much of Antarctica's current terrestrial fauna, with estimates spanning from hundreds of thousands to millions of years. Parochlus steinenii, commonly known as the Antarctic winged midge, stands out as one of the only two insect species native to Antarctica. Distributed across three biogeographic regions, southern South America and the Falkland/Malvinas Islands, sub-Antarctic South Georgia and the Maritime Antarctic South Shetland Islands, this midge raises questions about the temporal isolation of its populations and their divergence. Employing mitochondrial and nuclear genetic markers, we conducted phylogeographic and demographic analyses on 151 individuals of P. steinenii obtained across the three main biogeographic regions including the Magellanic sub-Antarctic Ecoregion (MSE) of southern South America, the sub-Antarctic Island of South Georgia (SG) and the South Shetland Islands (SSI) within the Maritime Antarctic (MA). Our data support the diversification of P. steinenii during the mid-Pleistocene around 1.46 Mya. This period included a branching event between a clade containing only specimens from the MSE and a clade containing individuals from a broader range of locations including the SSI and SG. Based on intraspecific phylogeographic and demographic inferences, we detected strong evolutionary divergence between the three main biogeographic regions. We also detected a signal of population growth during the deglaciation process in SSI and SG, contrary to the pattern seen in the MSE. The different demographic and phylogeographic histories between the sampled biogeographic regions could result from the MA and SG experiencing a strong genetic bottleneck due to a reduction in population size during the Last Glacial Maximum, while the MSE maintained a significant effective population size. The high level of divergence detected between individuals from the MSE and the remaining biogeographic regions supports the hypothesis of a speciation process taking place in P. steinenii.
  • No Thumbnail Available
    Item
    Ecological features of exotic Vespula wasps (Hymenoptera: Vespidae) invading the southernmost UNESCO Biosphere Reserve
    (2022) Rendoll-Carcamo, Javier; Convey, Peter; Ganan, Melisa; Maldonado-Marquez, Alan; Zuniga, Luna Menares; Contador, Tamara
    Invasive alien species may cause substantial changes and damaging impacts. Here, we document the current distribution and ecological interactions with native biota of relatively recently introduced wasps, Vespula vulgaris and V. germanica, in the southern part of the Cape Horn Biosphere Reserve (CHBR) in southern Chile. We conducted field studies in four different habitats on Navarino Island: evergreen, deciduous and mixed forests, and shrublands. The spread of V. vulgaris throughout the island has led to it occupying suitable habitats in both urban and rural settings, while V. germanica has not been observed in the last 2 years. The presence of V. vulgaris in remote areas of the CHBR is likely the result of human-mediated movement through the channels within the reserve. The composition of foraged items was different in each of the four studied habitats, yet strongly linked to the resources of each, indicating the inherent ability of V. vulgaris to exploit available resources efficiently. V. vulgaris mainly forages berries from shrubs, and preys on a variety of arthropods, particularly hoverflies, craneflies and lepidoptera larvae. The lack of natural competitors and availability of multiple resources has allowed V. vulgaris to rapidly become a common pest in urban and rural settings in the southern extremity of South America. While we consider that eradication would now be impossible, population control at local scales may still be possible with proper planning and long-term management. Our data provide a baseline for management planning, and we strongly recommend social engagement and dialog with relevant governmental institutions to achieve this challenging task.
  • No Thumbnail Available
    Item
    Occurrence of the Non-Native Annual Bluegrass on the Antarctic Mainland and Its Negative Effects on Native Plants
    (2012) Molina-Montenegro, Marco A.; Carrasco-Urra, Fernando; Rodrigo, Cristian; Convey, Peter; Valladares, Fernando; Gianoli, Ernesto
    Few non-native species have colonized Antarctica, although increased human activity and accelerated climate change may increase their number, distributional range, and effects on native species on the continent. We searched 13 sites on the maritime Antarctic islands and 12 sites on the Antarctic Peninsula for annual bluegrass (Poa annua), a non-native flowering plant. We also evaluated the possible effects of competition between P. annua and 2 vascular plants native to Antarctica, Antarctic pearlwort (Colobanthus quitensis) and Antarctic hairgrass (Deschampsia antarctica). We grew the native species in experimental plots with and without annual bluegrass under conditions that mimicked the Antarctic environment. After 5 months, we measured photosynthetic performance on the basis of chlorophyll fluorescence and determined total biomass of both native species. We found individual specimens of annual bluegrass at 3 different sites on the Antarctic Peninsula during the 20072008 and 20092010 austral summers. The presence of bluegrass was associated with a statistically significant reduction in biomass of pearlwort and hairgrass, whereas the decrease in biomass of bluegrass was not statistically significant. Similarly, the presence of bluegrass significantly reduced the photosynthetic performance of the 2 native species. Sites where bluegrass occurred were close to major maritime routes of scientific expeditions and of tourist cruises to Antarctica. We believe that if current levels of human activity and regional warming persist, more non-native plant species are likely to colonize the Antarctic and may affect native species.
  • No Thumbnail Available
    Item
    Shifting Perspectives in Polar Research: Global Lessons on the Barriers and Drivers for Securing Academic Careers in Natural Sciences
    (2021) Figuerola, Blanca; Valiente, Nicolas; Barbosa, Andres; Brasier, Madeleine J.; Colominas-Ciuro, Roger; Convey, Peter; Liggett, Daniela; Fernandez-Martinez, Miguel Angel; Gonzalez, Sergi; Griffiths, Huw J.; Jawak, Shridhar D.; Merican, Faradina; Noll, Daly; Prudencio, Janire; Quaglio, Fernanda; Pertierra, Luis R.
    The polar regions provide valuable insights into the functioning of the Earth's regulating systems. Conducting field research in such harsh and remote environments requires strong international cooperation, extended planning horizons, sizable budgets and long-term investment. Consequently, polar research is particularly vulnerable to societal and economic pressures during periods of austerity. The global financial crisis of 2008, and the ensuing decade of economic slowdown, have already adversely affected polar research, and the current COVID-19 pandemic has added further pressure. In this article we present the outcomes of a community survey that aimed to assess the main barriers and success factors identified by academic researchers at all career stages in response to these global crises. The survey results indicate that the primary barriers faced by polar early and mid-career researchers (EMCRs) act at institutional level, while mitigating factors are developed at individual and group levels. Later career scientists report pressure toward taking early retirement as a means of institutions saving money, reducing both academic leadership and the often unrecognized but vital mentor roles that many play. Gender and social inequalities are also perceived as important barriers. Reorganization of institutional operations and more effective strategies for long-term capacity building and retaining of talent, along with reduction in non-research duties shouldered by EMCRs, would make important contributions toward ensuring continued vitality and innovation in the polar research community.
  • No Thumbnail Available
    Item
    TerrANTALife 1.0 Biodiversity data checklist of known Antarctic terrestrial and freshwater life forms
    (Springer, 2024) Pertierra, Luis R.; Varliero, Gilda; Barbosa, Andres; Biersma, Elisabeth M.; Convey, Peter; Chown, Steven L.; Cowan, Don; De Los Rios, Asuncion; Escribano-Alvarez, Pablo; Fontaneto, Diego; Fraser, Ceridwen; Harris, Mathew; Hughes, Kevin; Griffiths, Huw; le Roux, Peter; Liu, Xiaoyue P.; Lynch, Heather; Majewska, Roksana; Martinez, Pablo A.; Molina-Montenegro, Marco; Olalla-Tarraga, Miguel A.; Peck, Lloyd; Quesada, Antonio; Ronquillo, Cristina; Ropert-Coudert, Yan; Sancho, Leopoldo; Terauds, Aleks; Vianna, Juliana; Wilmotte, Annick; Hortal, Joaquin; Greve, Michelle; CEDEUS (Chile)
    Background Incomplete species inventories for Antarctica represent a key challenge for comprehensive ecological research and conservation in the region. Additionally, data required to understand population dynamics, rates of evolution, spatial ranges, functional traits, physiological tolerances and species interactions, all of which are fundamental to disentangle the different functional elements of Antarctic biodiversity, are mostly missing. However, much of the fauna, flora and microbiota in the emerged ice -free land of the continent have an uncertain presence and/or unresolved status, with entire biodiversity compendia of prokaryotic groups (e.g. bacteria) being missing. All the available biodiversity information requires consolidation, cross -validation, re -assessment and steady systematic inclusion in order to create a robust catalogue of biodiversity for the continent. New information We compiled, completed and revised eukaryotic species inventories present in terrestrial and freshwater ecosystems in Antarctica in a new living database: terrANTALife (version 1.0). The database includes the first integration in a compendium for many groups of eukaryotic microorganisms. We also introduce a first catalogue of amplicon sequence variants (ASVs) of prokaryotic biodiversity. Available compendia and literature to date were searched for Antarctic terrestrial and freshwater species, integrated, taxonomically harmonised and curated by experts to create comprehensive checklists of Antarctic organisms. The final inventories comprises 470 animal species (including vertebrates, freeliving invertebrates and parasites), 306 plants (including all Viridiplantae: embryophytes and green algae), 997 fungal species and 434 protists (sensu lato). We also provide a first account for many groups of microorganisms, including non-lichenised fungi and multiple groups of eukaryotic unicellular species (Stramenophila, Alveolata and Rhizaria (SAR), Chromists and Amoeba), jointly referred to as "protists". In addition, we identify 1753 bacterial (obtained from 348117 ASVs) and 34 archaeal genera (from 1848 ASVs), as well as, at least, 14 virus families. We formulate a basic tree of life in Antarctica with the main lineages listed in the region and their "known-accepted-species" numbers.