MERRAclim Dataset. 19 global bioclimatic variables from the 1990s decade at 5 arcminutes resoluti... more MERRAclim Dataset. 19 global bioclimatic variables from the 1990s decade at 5 arcminutes resolution in GEOtiff format. The humidity version used is the min. The variables have been built using the same protocol as WorldClim with data from MERRA. Temperature layers (BIO1-BIO11) are in degree Celsius multiplied by 10, humidity layers (BIO12-BIO19) are in kg of water/kg of air multiplied by 100000
MERRAclim Dataset. 19 global bioclimatic variables from the 2000s decade at 2.5 arcminutes resolu... more MERRAclim Dataset. 19 global bioclimatic variables from the 2000s decade at 2.5 arcminutes resolution in GEOtiff format. The humidity version used is the mean. The variables have been built using the same protocol as WorldClim with data from MERRA. Temperature layers (BIO1-BIO11) are in degree Celsius multiplied by 10, humidity layers (BIO12-BIO19) are in kg of water/kg of air multiplied by 100000
MERRAclim Dataset. 19 global bioclimatic variables from the 2000s decade at 5 arcminutes resoluti... more MERRAclim Dataset. 19 global bioclimatic variables from the 2000s decade at 5 arcminutes resolution in GEOtiff format. The humidity version used is the mean. The variables have been built using the same protocol as WorldClim with data from MERRA. Temperature layers (BIO1-BIO11) are in degree Celsius multiplied by 10, humidity layers (BIO12-BIO19) are in kg of water/kg of air multiplied by 100000
MERRAclim Dataset. 19 global bioclimatic variables from the 1990s decade at 5 arcminutes resoluti... more MERRAclim Dataset. 19 global bioclimatic variables from the 1990s decade at 5 arcminutes resolution in GEOtiff format. The humidity version used is the max. The variables have been built using the same protocol as WorldClim with data from MERRA. Temperature layers (BIO1-BIO11) are in degree Celsius multiplied by 10, humidity layers(BIO12-BIO19) are in kg of water/kg of air multiplied by 100000
The polar regions provide valuable insights into the functioning of the Earth’s regulating system... more 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 ...
Ensemble forecasting of invasion risk for four alien springtail (Collembola) species in Antarctica
Polar Biology, 2021
Outputs of the species distribution modelling of introduced collembola in the Antarctic Peninsula... more Outputs of the species distribution modelling of introduced collembola in the Antarctic Peninsula. Code available at: https://github.com/gretacv/SDMcollembola Biological invasions are one of the most important threats to Antarctic biodiversity. Springtails (Collembola) make up most of the diversity in soil arthropod communities in Antarctic terrestrial ecosystems. However, the potential range expansion of already established alien springtails and their consequent impacts on Antarctic ecosystems remains largely unknown. Species Distribution Models (SDMs) are a useful tool to identify areas potentially suitable for the geographical spread of alien species that are as yet unoccupied. In Antarctica, however, the application of SDMs is relatively more recent compared to the rest of the planet and received greater initial attention in marine environments. Here, we implement an ensemble forecasting approach and compute eight modelling algorithms to better understand the geographic distributions and potential range dynamics of four reportedly established alien springtail species (<em>Hypogastrura viatica</em>, <em>Folsomia candida</em>, <em>Mesaphorura macrochaeta</em> and <em>Proisotoma minuta</em>) on the Antarctic Peninsula. Our models identify several ice-free areas across the South Shetland Islands which offer highly suitable environmental conditions for establishment. Thus, biosecurity provisions ought to be reinforced in those sites more vulnerable to invasions. Model predictions of our ensemble SDM approach would benefit from additional field sampling effort across the introduced range and could be complemented with mechanistic models that critically need experimental physiological data to define the fundamental climatic niche of each species.
Proceedings of the National Academy of Sciences, 2020
Significance Penguins have long been of interest to scientists and the general public, but their ... more Significance Penguins have long been of interest to scientists and the general public, but their evolutionary history remains unresolved. Using genomes, we investigated the drivers of penguin diversification. We found that crown-group penguins diverged in the early Miocene in Australia/New Zealand and identified Aptenodytes (emperor and king penguins) as the sister group to all other extant penguins. Penguins first occupied temperate environments and then radiated to cold Antarctic waters. The Antarctic Circumpolar Current’s (ACC) intensification 11.6 Mya promoted penguin diversification and geographic expansion. We detected interspecies introgression among penguins, in some cases following the direction of the ACC, and identified genes acting on thermoregulation, oxygen metabolism, and diving capacity that underwent adaptive evolution as they progressively occupied more challenging thermal niches.
This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
1. Rising human activity in Antarctica, combined with continued warming of the polar climate, mea... more 1. Rising human activity in Antarctica, combined with continued warming of the polar climate, means the risk of non-native terrestrial species colonising and establishing in its biodiversity-and nutrient-poor ecosystems is increasing. 2. Of the five non-native invertebrate species currently in terrestrial Antarctica, the flightless midge Eretmoptera murphyi (Schaeffer, The Museum of the Brooklyn Institute of Arts and Sciences 2:90-94, 1914) is perhaps the most persistent insect invader. Accidentally introduced to Signy Island (60 S) in the 1960s from sub-Antarctic South Georgia (54 S), E. murphyi has steadily increased its distribution, however, its status has not been reassessed for a decade. 3. Here, we update the distribution of E. murphyi on Signy, specifically assessing whether footpaths to regularly visited research sites represent dispersal corridors. 4. Our findings show that both the abundance and range of E. murphyi have increased significantly since 2009, particularly along paths leading away from the original introduction site, and that the species is now on the cusp of moving into new valley systems. 5. We identify a moderate association with soil/substrate and vegetation types and build Maximum Entropy (MaxEnt) models to predict areas of the island that may be at highest risk of future colonisation. 6. As a detritivore with no competitors or predators, E. murphyi may have a major impact. For example, accelerating nutrient cycling which may have wider impacts on all levels of biodiversity. 7. This study highlights the need for an assessment of current biosecurity protocols applied within the Antarctic Treaty system, as well as the need for systematic regular monitoring of introduced and invasive species in Antarctica.
Evaluating ecosystem services in Antarctica-why are we falling behind? E cosystem services descri... more Evaluating ecosystem services in Antarctica-why are we falling behind? E cosystem services describe the many benefits provided by healthy functioning ecosystems, including food provision, climate regulation and recreational benefits. An assessment and understanding of ecosystem services has directed effective conservation and/or management in many areas across the globe. Policymakers are starting to embrace ecosystem services studies that focus on the Southern Ocean, but equivalent studies for Antarctic terrestrial environments are still largely absent. Why is this when the ecosystem services provided to humans by the Antarctic terrestrial environment are clear? For example, the role of Antarctic ice masses on global regulation services are massive while also locally driving changes in downstream ice-free areas (Milner et al. 2017). Moreover, Antarctic researchers use Antarctica as a pristine natural laboratory to deliver research advances and the tourism industry is sustained by the cultural ecosystem services that make Antarctica such an astounding tourism destination. By utilising these services, parts of Antarctica are becoming increasingly busy and Antarctic values are under increasing pressure. This makes the application of ecosystem services assessment frameworks to inform the use of existing environmental management tools by the Antarctic Treaty Parties all the more urgent. The latest Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services report (IPBES 2019) highlighted the changes in land use, pollution and warming that are affecting the Polar Regions, while emphasizing the role of ecosystem services in underpinning Biodiversity Conservation Targets. The report warned of global trade-offs between the many ways' nature benefits people, including for example, the production of food and other commodities over regulation of air and water quality, climate regulation and habitat provision. Notably, the Antarctic region was only mentioned once with a reference to the risks associated with future seabed mining. Lack of consideration of the Antarctic may be due to the limited number of studies explored ecosystem services in Antarctica: only two have been undertaken, which focus on Southern Ocean fishing (Grant et al. 2013) and on payment for recreational activities (Verbansky 2018). In contrast, studies on various Ecosystem Services at the Arctic region are much more frequent (Malinauskaite et al. 2019). Strikingly, none of the global IPBES assessments and projections include the Antarctic continent despite it being a major provider of globally essential ecosystem services. One explanation for the lack of ecosystem services studies for terrestrial Antarctica might relate to the unique governance arrangements of the Antarctic Treaty area. Use of established mechanisms to consider environmental issues mean there may be an initial reluctance to embrace the new terminology and concepts presented by ecosystem services assessments. However, similarities exist between the values described by the Antarctic Treaty System and established ecosystem services classifications. For example, scientific, historical, aesthetic and wilderness values are all core 'cultural' ecosystem services. Helpfully, spatial ecosystem services assessments can be particularly effective in managing trade-offs between different cultural ecosystem services. A second and more practical reason for slow implementation of ecosystem services studies may be the limited geospatial resources available to create high-resolution maps needed for the assessments. However, spatial information is becoming increasingly accessible, and terrestrial biodiversity data is being systematically compiled and centralized, making this less of an issue. A third reason is that undertaking ecosystem services assessments needs financial support and the identification of strong 'champions' to clearly communicate its importance to funders. In Antarctic marine ecosystems, the financial value of supporting services, including fisheries, may be sufficient to justify the expense. In contrast, the range of beneficiaries of ecosystem services in terrestrial Antarctica have been less vocal in recognizing them explicitly, making allocation of funds to support ecosystem services assessments less of a priority for national funding bodies. However, given the pace of change in Antarctica, with an increase in distribution and diversity of national operator and tourism industry activities, can we afford further delay? Some progress in identifying locations that deliver ecosystem services has been made, albeit as a secondary benefit of the existing work of the Committee for Environmental Protection. For example, the system of Site Guidelines for Visitors show locations where some features of recreational value are present (e.g. rookeries and rich vegetation), and the list of Historic Sites and Monuments (HSMs) and 72 Antarctic Specially Protected Area (ASPA) management plans describe features of outstanding historic, conservation or scientific value. However, Site Guidelines, ASPAs and HSMs focus on spatially restricted areas for a limited range of ecosystem services connected with specific Antarctic
Higher education institutions (HEIs) have been steadily progressing towards the integration of su... more Higher education institutions (HEIs) have been steadily progressing towards the integration of sustainable practices in their structures and operations. Several studies have reported the variety of drivers of change and the barriers to change that universities have found in the integration process. The present investigation is aimed at further characterizing and ranking the drivers for, and barriers of, sustainability integration in HEIs within their structures and operating functions. Open-ended expert opinion interviews of key sustainability leaders appointed at 45 HEIs from 10 Latin-American countries were conducted in order to learn lessons from their diverse experiences of the process. Additionally, a thematic workshop on HEI sustainability was organized to facilitate further discussions between 23 sustainability scholars and/or national coordinators of university networks from 11 Latin American countries. As a result, 15 barriers were identified as hindering the institutionali...
Species Distribution Models (SDMs) combine information on the geographic occurrence of species wi... more Species Distribution Models (SDMs) combine information on the geographic occurrence of species with environmental layers to estimate distributional ranges and have been extensively implemented to answer a wide array of applied ecological questions. Unfortunately, most global datasets available to parameterize SDMs consist of spatially interpolated climate surfaces obtained from ground weather station data and have omitted the Antarctic continent, a landmass covering c. 20% of the Southern Hemisphere and increasingly showing biological effects of global change. Here we introduce MERRAclim, a global set of satellite-based bioclimatic variables including Antarctica for the first time. MERRAclim consists of three datasets of 19 bioclimatic variables that have been built for each of the last three decades (1980s, 1990s and 2000s) using hourly data of 2 m temperature and specific humidity. We provide MERRAclim at three spatial resolutions (10 arc-minutes, 5 arc-minutes and 2.5 arc-minutes...
The ongoing introduction of non-native species to Antarctica due to expanding human activity pres... more The ongoing introduction of non-native species to Antarctica due to expanding human activity presents an increasing threat to biodiversity. Under the Protocol on Environmental Protection to the Antarctic Treaty, all introduced non-native species should be removed from the Antarctic Treaty area. The nonnative grass Poa pratensis was first introduced to Cierva Point (Danco Coast, Antarctic Peninsula), along with substantial quantities of non-Antarctic soil, in the mid-1950s. Consistent with the Protocol, in January 2015 an internationally coordinated team undertook the eradication of the grass. Immediately prior to removal of P. pratensis, factors affecting its establishment, persistence and impacts upon local indigenous species was examined within the international management framework of the Antarctic Treaty System. The underlying soil had a high organic content of 15.5%, which may have contributed to the successful establishment of P. pratensis and restricted, at least initially, its vegetative growth to the enriched area. Examination of P. pratensis expansion from the original introduction sites showed that the plant colony intricate root system facilitated little or no coexistence of other native plants within its extent. The non-native plant colony also constituted a novel habitat for soil fauna within Antarctic terrestrial environments. The P. pratensis plant colony provided an unfavorable habitat for two of the locally endemic soil invertebrates, Cryptopygus antarcticus and Belgica antarctica. These observations led to the selection of an appropriate eradication approach, where the plants were targeted for physical extraction along with all underlying soil. During the eradication, c. 500 kg of soil and plant material from the P. pratensis colony was removed from the site. Monitoring one year later showed no evidence of reestablishment. Consistent with the Committee for Environmental Protection 'Non-native Species Manual', we recommend development and implementation of rapid response protocols following the discovery of a non-native plant colony to limit future impacts on indigenous species and local habitats.
The main soil physical-chemical features, the concentrations of a set of pollutants, and the soil... more The main soil physical-chemical features, the concentrations of a set of pollutants, and the soil microbiota linked to penguin rookeries have been studied in 10 selected sites located at the South Shetland Islands and the Antarctic Peninsula (Maritime Antarctica). This study aims to test the hypothesis that biotransport by penguins increases the concentration of pollutants, especially heavy metals, in Antarctic soils, and alters its microbiota. Our results show that penguins do transport certain chemical elements and thus cause accumulation in land areas through their excreta. Overall, a higher penguin activity is associated with higher organic carbon content and with higher concentrations of certain pollutants in soils, especially cadmium, cooper and arsenic, as well as zinc and selenium. In contrast, in soils that are less affected by penguins' faecal depositions, the concentrations of elements of geochemical origin, such as iron and cobalt, increase their relative weighted co...
Human footprint models allow visualization of human spatial pressure across the globe. Up until n... more Human footprint models allow visualization of human spatial pressure across the globe. Up until now, Antarctica has been omitted from global footprint models, due possibly to the lack of a permanent human population and poor accessibility to necessary datasets. Yet Antarctic ecosystems face increasing cumulative impacts from the expanding tourism industry and national Antarctic operator activities, the management of which could be improved with footprint assessment tools. Moreover, Antarctic ecosystem dynamics could be modelled to incorporate human drivers. Here we present the first model of estimated human footprint across predominantly ice-free areas of Antarctica. To facilitate integration into global models, the Antarctic model was created using methodologies applied elsewhere with land use, density and accessibility features incorporated. Results showed that human pressure is clustered predominantly in the Antarctic Peninsula, southern Victoria Land and several areas of East An...
Antarctic non-native species legislation is contained within the Protocol on Environmental Protec... more Antarctic non-native species legislation is contained within the Protocol on Environmental Protection to the Antarctic Treaty, with 2016 marking the 25th anniversary of its adoption. We take this opportunity to evaluate the Antarctic Treaty signatory Parties' collective development and implementation of non-native species policy. In general, scientific and policy outputs have increased in the past decade. However, data detailing Parties' current implementation of biosecurity practices are not readily available. Little widespread, internationally coordinated or systematic monitoring of non-native species establishment has occurred, but available data suggest that establishment of non-native micro-invertebrates may be greatly underestimated. Several recent small-scale plant eradications have been successful, although larger-scale eradications present a greater challenge due to seed bank formation. Invertebrate establishment within research station buildings presents an increasing problem, with mixed eradication success to date. The opportunity now exists to build on earlier successes, such as the 'CEP Non-native Species Manual', towards the development of a comprehensive response strategy based upon the principles of prevention, monitoring and response, and applicable to all Antarctic environments. To help facilitate this we identify areas requiring further research and policy development, such as to reduce anthropogenic transfer of indigenous Antarctic species between distinct biogeographic regions, avoid microbial contamination of pristine areas and limit introduction of non-native marine species. A response protocol is proposed for use following the discovery of a potential non-native species within the Antarctica Treaty area, which includes recommendations concerning Parties' initial response and any subsequent eradication or control measures.
Until recently the Antarctic continent and Peninsula have been little impacted by non-native spec... more Until recently the Antarctic continent and Peninsula have been little impacted by non-native species, compared to other regions of the Earth. However, reports of species introductions are increasing as awareness of biological invasions as a major conservation threat, within the context of increased human activities and climate change scenarios, has grown within the Antarctic community. Given the recent increase in documented reports, here we provide an up-to-date inventory of known terrestrial non-native species introductions, including those subsequently removed since the 1990s, within the Antarctic Treaty area. This builds on earlier syntheses of records published in the mid-2000s, which focused largely on the sub-Antarctic islands, given the dearth of literature available at that time from the continental and maritime Antarctic regions. Reports of non-native species established in the natural environment (i.e. non-synanthropic) are mainly located within the Antarctic Peninsula region and Scotia Arc, with Deception Island, South Shetland Islands, the most impacted area. Non-native plants have generally been removed from sites of introduction, but no established invertebrates have yet been subject to any eradication attempt, despite a recent increase in reports. Legislation within the Protocol on Communicated by Karen E. Hodges.
Soil trampling is one of the most obvious direct negative human impacts in Antarctica. Through a ... more Soil trampling is one of the most obvious direct negative human impacts in Antarctica. Through a range of experiments and field studies based on quantitative physical (soil penetration resistance) and biological (collembolan abundance) indicators, we evaluate the current codes of conduct relating to the protection of Antarctic soils from the consequences of pedestrian impacts. These guidelines include using, where available, established paths that cross vegetation-free soils. However, the effectiveness of this strategy is highly dependent on context. Limited intensity use*below 100 foot passes per year* produces small changes at the soil surface that can recover relatively rapidly, suggesting that the dispersal of activity across wider corridors may be the most appropriate option. However, for paths with a higher use level and those located in steep-sloped sites, it is desirable to define a single track, following stony or bouldery surfaces wherever possible, to keep the disturbed area to a minimum. It is clear that both environmental conditions and expected use levels must be taken into account in determining when and where it is more appropriate to concentrate or disperse human activities. Even though they may have performed satisfactorily to date, the increasing pressure in terms of numbers of visits for certain sites may make it necessary to revise existing codes of conduct.
A single colony of the non-native grass Poa pratensis L., which was introduced inadvertently to C... more A single colony of the non-native grass Poa pratensis L., which was introduced inadvertently to Cierva Point, Antarctic Peninsula, during the 1954-1955 season, was still present during a survey in February 2012, making it the longest surviving non-native vascular plant colony known in Antarctica. Since 1991, the grass cover has roughly tripled in size, with an annual increase in area of approximately 0.016 m 2 , and an estimated maximum radial growth rate of 1.43 cm y-1. However, it remains restricted to the original site of introduction and its immediate surroundings (c. 1 m 2). Annual flowering of the plants occurred during the 2010/2011 and 2011/2012 seasons; however, there has been no seed production and only incomplete development of the sexual structures. Current environmental conditions, including low temperatures, may inhibit sexual reproduction. Lack of effective vegetative dispersal may be influenced by the low level of human activity at the site, which limits opportunities for human-mediated dispersal. Although P. pratensis has existed at Cierva Point for almost 60 years, it has not yet become invasive. Scenarios for the potential future development of the species in Antarctica and the associated negative impacts upon the native vegetation from competition are discussed in the context of regional climate change. Finally, we describe the environmental risk presented by P. pratensis and argue that this non-native species should be eradicated as soon as possible in accordance with the Protocol on Environmental Protection to the Antarctic Treaty.
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