Antarctica harbors many distinctive features of life, yet much about the diversity and functioning of Antarctica’s life remains unknown. Evolutionary histories and functional ecology are well understood only for vertebrates, whereas research on invertebrates is largely limited to species descriptions and some studies on environmental tolerances. Knowledge on Antarctic vegetation cover showcases the challenges of characterizing population trends for most groups. Recent community-level microbial studies have provided insights into the functioning of life at its limits. Overall, biotic interactions remain largely unknown across all groups, restricted to basic information on trophic level placement. Insufficient knowledge of many groups limits the understanding of ecological processes on the continent. Remedies for the current situation rely on identifying the caveats of each ecological discipline and finding targeted solutions. Such precise delimitation of knowledge gaps will enable a more aware, representative, and strategic systematic conservation planning of Antarctica.

Polar regions are heavily impacted by climate change. Yet, vulnerability assessments suggest little concern about heat-related challenges for polar terrestrial ectotherms. These conclusions are based, however, on assumptions and extrapolation from temperate regions; the limited data available suggest that polar ectotherms are more sensitive to warming than previously recognized.

Human-caused climate change worsens with every increment of additional warming, although some impacts can develop abruptly. The potential for abrupt changes is far less understood in the Antarctic compared with the Arctic, but evidence is emerging for rapid, interacting and sometimes self-perpetuating changes in the Antarctic environment. A regime shift has reduced Antarctic sea-ice extent far below its natural variability of past centuries, and in some respects is more abrupt, non-linear and potentially irreversible than Arctic sea-ice loss. A marked slowdown in Antarctic Overturning Circulation is expected to intensify this century and may be faster than the anticipated Atlantic Meridional Overturning Circulation slowdown. The tipping point for unstoppable ice loss from the West Antarctic Ice Sheet could be exceeded even under best-case CO2 emission reduction pathways, potentially initiating global tipping cascades. Regime shifts are occurring in Antarctic and Southern Ocean biological systems through habitat transformation or exceedance of physiological thresholds, and compounding breeding failures are increasing extinction risk. Amplifying feedbacks are common between these abrupt changes in the Antarctic environment, and stabilizing Earth's climate with minimal overshoot of 1.5 °C will be imperative alongside global adaptation measures to minimise and prepare for the far-reaching impacts of Antarctic and Southern Ocean abrupt changes.

Aerated caves receive minimal light energy, yet host diverse microbial communities and the strategies allowing them to meet energy and carbon needs remain unclear. We determined the processes and mediators of primary production in aerated limestone and basalt caves through paired metagenomic and biogeochemical profiling. Four caves were sampled, including sediments and biofilms, yielding 94 metagenomes. Based on 1458 metagenome-assembled genomes, over half of microbial cells encode enzymes to use atmospheric trace gases as energy and carbon sources. The most abundant microbes are chemosynthetic primary producers, notably the gammaproteobacterial methanotrophic order Ca. Methylocavales and two uncultivated actinobacterial genera predicted to grow on atmospheric hydrogen, carbon dioxide, and carbon monoxide. Biogeochemical and isotopic measurements confirmed that these gases are rapidly consumed at rates likely sustaining a substantial fraction of the community and potentially driving primary production. Conventional chemolithoautotrophs, using ammonium and sulfide, are also enriched and active. Altogether, these results indicate that caves are unique in microbial biodiversity and the biogeochemical processes sustaining them. Consumption of atmospheric trace gases likely has a dual role in caves, providing energy for microbial survival and potentially supporting chemosynthetic growth, thereby introducing organic carbon. This process, defined as 'aerotrophy', operates alongside organic and inorganic inputs.

Reducing the rates and impacts of biological invasions is a major policy goal of international biodiversity agreements. Yet the extent to which this goal is being achieved and the agreements hence successful in this respect remains unclear. Here we use a comprehensive record of alien species introduction in the terrestrial Antarctic, including its surrounding Southern Ocean Islands, spanning 115 years (1900–2015), to quantify the impact of biosecurity policy on alien species introduction rates in the region, where invasive alien species are a primary environmental conservation threat and management priority. We show that although many parts of the Antarctic have been colonized by non‐indigenous taxa, recent rates of introduction appear to be slowing or static in most parts, compared with increases in the past. Our results vindicate the regional Antarctic focus on biosecurity measures, but also demonstrate the need for stricter enforcement due to rapid socio‐environmental changes.

The leaf economics spectrum links strategies of plant investment in resource-acquiring leaves to overall fitness. We test whether an economic spectrum can also explain variation in ecological strategies of ant species across environmental gradients, where colony investment in workers is analogous to plant investment in leaves. A fast return of resource investment was associated with large colonies of smaller, less robust, short-lived workers with low nitrogen:phosphorus ratios. Slow resource payback was associated with small colonies of densely built, energetically conservative and longer-lived workers with high nitrogen:phosphorus ratios. Species representing the entire economic continuum co-occurred in all communities. Phylogenetic analyses suggest genus level conservation of core investment templates. These results unify studies of plants and ants, suggesting common economic principles apply across the tree of life.

Metabolic rate dictates life's tempo, yet how ecological and environmental factors integrate to shape metabolic traits remains contentious. Considering metabolic traits of 114 species of ants from seven subfamily clades along a 1,500 km climatic and soil phosphorus availability gradient in Australia, we tested four hypotheses relating to variation in metabolic rate due to niche conservatism, temperature, aridity, and ecological stoichiometry. We also tested the contested hygric hypothesis, which predicts that insect ventilation patterns can be modified to reduce water loss in arid environments. Mass-independent metabolic rate was phylogenetically conserved. The ant clade Myrmecia had metabolic rates 3 to 10× higher than other species, likely related to their large eye size, a correlate of cognitive complexity. Metabolic rate was higher in ants from warm, arid sites relative to those from wet, cool sites. A weak positive interaction between soil phosphorus and body mass indicated that, at sites with low soil phosphorus, smaller ants respired at higher rates than expected based on their mass-consistent with ecological stoichiometry theory. Larger ants, regardless of clade, were more likely to exhibit discontinuous gas exchange (DGC) with increasing aridity, likely reflecting a water conservation strategy. Phylogenetic conservatism of metabolic rate and a moderate influence of environment suggest that, in addition to biophysical geometric constraints, metabolic rate has evolved to match the energetic demands required of ecological strategies to address environmental stressors. For larger insect species confronting their metabolic limits, DGC may promote resilience in a world that is becoming hotter and more arid.

Gough Island is part of the Tristan da Cuhna archipelago in the South Atlantic Ocean. The island’s significant conservation status necessitates determining the fauna and its origin. This study reports the occurrence of 63 mite species at Gough, adding greatly to the six previously known species for the island. These records constitute 30 confirmed species (cr), 13 morphological variants of nominate species (nr), 15 likely new species with no clear close relative (sp. nov.) and five currently undetermined species (sp). The fauna comprises predominantly Mesostigmata (24 species) and Oribatida (21), with fewer Prostigmata (8) and Astigmatina species (10). Habitat specificity across high-altitude, low altitude and marine boulder beach (and supralittoral) biotopes was comparatively low for the mesostigmatid mites and high for the oribatid and astigmatine mites. Global geographical realm associations based on the confirmed and morphological-variant species are greatest for the Antarctic (19 species), followed by the Holarctic (13 species). Whereas human introductions originate predominantly from the Holarctic, involving mainly mesostigmatid mites, obligatory marine mites are natural colonizers from the Antarctic realm. The numerous morphological variants and new species imply significant isolation, speciation and endemism. Overall, human introduction accounts for 20

Antarctica is one of Earth's most untouched, inhospitable, and poorly known regions. Although knowledge of its biodiversity has increased over recent decades, a diverse, wide-ranging, and spatially explicit compilation of the biodiversity that inhabits Antarctica's permanently ice-free areas is unavailable. This absence hinders both Antarctic biodiversity research and the integration of Antarctica in global biodiversity-related studies. Fundamental and applied research on biodiversity patterns, ecological structure and function, and options for conservation are reliant on spatially resolved, taxonomically consistent observations. Such information is especially important for modern, data-driven biodiversity science, in both Antarctica and globally, and forms the backbone of biodiversity informatics, reflected, for example, in the Darwin Core Standard used by the Global Biodiversity Information Facility. Biodiversity data are also essential to fulfill the conservation requirements for Antarctica, as set out in the Protocol on Environmental Protection to the Antarctic Treaty and inform the design of systematic surveys to address biodiversity and ecological knowledge gaps, for both specific taxa and ecosystems. Such surveys are key requirements for understanding and mitigating the impacts of environmental change on the region's biodiversity. Here, we address these requirements through the public release of The Biodiversity of Ice-free Antarctica Database. In 2008, we extracted a subset of biodiversity records only from terrestrial ice-free areas from the Scientific Committee on Antarctic Research (SCAR) Antarctic Biodiversity Database. We have subsequently added thousands of records from a range of sources: checking, and where necessary (and possible), correcting the spatial location, clarifying, cross-referencing, and harmonizing taxonomy with globally recognized sources, and documenting the original source of records. The Biodiversity of Ice-free Antarctica Database spans the early 1800s to 2019 (with most records collected after 1950) and represents the most comprehensive consolidation of Antarctic ice-free biodiversity occurrence data yet compiled into a single database. The Biodiversity of Ice-free Antarctica Database contains 35,654 records of 1890 species in over 800 genera across six kingdoms and spans all Antarctic Conservation Biogeographic Regions. These data are released under a CC BY Attribution License (http://creativecommons.org/licenses/by/4.0/).

Urban informal settlement residents are vulnerable to mosquito-borne diseases, but little is known about the specific drivers of risk, or how they differ, within the diversity of informal settlements globally. Here we aimed to identify key drivers of mosquito abundance in different urban informal settlements to inform upgrading programs. We developed a causal framework of mosquito risk and tested it in two distinct geographic settings: Makassar, Indonesia and Suva, Fiji. Using longitudinal mosquito trapping surveys in 24 informal settlements between 2018 and 2024 (totalling 1534 successful trap sets in Makassar and 1216 in Suva), we fitted causal models to infer the relationships between climatic, environmental and socioeconomic drivers and the abundance of two dominant mosquito species: Aedes aegypti and Culex quinquefasciatus . Water supply and access, and variation in temperature and precipitation were key drivers of mosquito abundance in both informal settlement locations, but the direction of effects differed between vector species. Piped water supply in a settlement reduced the abundance of the dengue vector, Ae. aegypti but increased the abundance of Cx. quinquefasciatus. Higher temperature and precipitation were associated with more Ae. aegypti in both geographic locations. By identifying the pathways through which changes in informal settlement environments are likely to alter mosquito risk we provide essential information to guide upgrading and resilience programs.

Antarctica, Earth’s least understood and most remote continent, is threatened by human disturbances and climate-related changes, underscoring the imperative for biodiversity inventories to inform conservation. Antarctic ecosystems support unique species and genetic diversity, deliver essential ecosystem services and contribute to planetary stability. We present Antarctica’s first comprehensive ecosystem classification and map of ice-free lands, which host most of the continent’s biodiversity. We used latent variables in factor analyses to partition continental-scale abiotic variation, then biotic variation represented in spatial models, and finally recognised regional-scale variation among biogeographic units. This produced a spatially explicit hierarchical classification with nine Major Environment Units (Tier 1), 33 Habitat Complexes (Tier 2) and 269 Bioregional Ecosystem Types (Tier 3) mapped at 100 m resolution and aligned with ‘level 4’ of the IUCN Global Ecosystem Typology. This comprehensive ecosystem inventory provides foundational data to inform protected area designation under the Antarctic Treaty’s Environmental Protocol and track risks to Antarctic ecosystems. Its tiered structure and workflow accommodate data scarcity and facilitate updates, promoting robustness as knowledge builds.

Endemism is a highly valuable metric for conservation because it identifies areas with irreplaceable species, ecological functions, or evolutionary lineages. Global analyses of endemism currently fail to identify the most irreplaceable areas because the commonly used endemism metrics are correlated with richness, and entire regions, especially low-richness areas in the southern hemisphere, are regularly excluded. Global patterns of endemism are therefore still insufficiently known. Here, using metrics representing irreplaceability, we unveil global patterns of avian taxonomic, functional, and phylogenetic endemism that show striking differences between hemispheres. Across all facets of diversity, endemism decreases poleward in the northern hemisphere but increases poleward in the southern hemisphere, resulting in a global north-south increase in endemism. The pattern appears to be driven by smaller and increasingly discontinuous landmasses towards the south which lead to smaller ranges and reduced overlap in community composition, as well as to global peaks of diversity relative to available area in the southern hemisphere. Our findings suggest that there are key areas of irreplaceability that might be missed if analyses are focused on species richness and omit species-poor regions. Highly endemic southern-hemisphere communities might be especially vulnerable to the climate crisis because discontinuous landmasses impede range shifts.

Fossil-fuel burning is heating the planet with catastrophic consequences for its habitability and for the natural world on which our existence depends. Halting global warming requires rapid and deep decarbonization to “net zero” carbon dioxide (CO2) emissions, which needs to be achieved by 2050 if warming is to remain within the limits set out by the 2015 Paris Agreement. However, some scientists and engineers claim that a mid-century decarbonization target will not be reached, and they propose that we should focus on technological geoengineering “fixes” or “climate interventions” that could delay or mask some of the impacts of global warming. They often cite the need to slow warming in polar regions because they are experiencing rates of warming higher than the global average, with severe and irreversible projected consequences both locally (e.g., on fragile ecosystems) and globally (e.g., on sea level). Several geoengineering concepts exist for polar regions, but they have not been fully examined by the polar science community, nor integrated with an understanding of polar dynamics and responses. Here, we evaluate five of those polar geoengineering concepts and highlight the significant issues and risks relating to technological availability, logistical feasibility, cost, predictable adverse consequences, environmental damage, scalability (in space and time), governance, and ethics. According to our expert assessment, none of these geoengineering ideas pass scrutiny regarding their use in the coming decades. Instead, we find that the proposed concepts would be environmentally dangerous. It is clear to us that the assessed approaches are not feasible, and that further research into these techniques would not be an effective use of limited time and resources. It is vital that these ideas do not distract from the priority to reduce greenhouse gas (GHG) emissions or from the critical need to conduct fundamental research in the polar regions.

### Geoengineering: solutions or distractions to the climate crisis? This session explores the technical feasibility, long-term costs, environmental risks, and governance limitations of five approaches. Examine the scientific and policy challenges of deploying polar geoengineering tools as a climate mitigation strategy. Hear from the authors of a [Frontiers in Science lead article](https://www.frontiersin.org/journals/science/articles/10.3389/fsci.2025.1527393/full)—including a representative of the Intergovernmental Panel on Climate Change (IPCC)—as they analyze five polar geoengineering proposals: aerosol injection, sea walls, ice albedo modification, basal water removal, and ocean fertilization. The researchers will outline their conclusions that these proposed interventions would harm the fragile polar ecosystems they intend to protect, and how the proposals fail to meet core scientific and policy criteria. Our expert panel will also discuss how these initiatives may detract from achieving Net Zero, by diverting time, funding, and attention from efforts toward achieving deep decarbonization. [Click here to register.](https://events.frontiersin.org/polar-geoengineering/cassyni)

Economic principles can be applied to biological life to understand how resource allocation strategies maximise evolutionary fitness. This approach has been applied in plants under the global slow-fast leaf economic spectrum which describes investment and return of carbon and nutrients in leaves. Whether this applies to other taxa, indicating general principles, remains untested. We advance generality in economic theories of life by showing that a slow-fast spectrum captures the resource economics of a globally dominant group of superorganisms, the ants. Like plants, ants acquire resources through modular units, the workers. Here, we collect traits from ant workers of 123 species across large-scale environmental gradients. Ants trade-off investment in biomass, chemical elements (nitrogen, phosphorus), energy (metabolic rate) and worker number, against assimilation rates (resource revenue) and lifespan. This superorganism economic spectrum does not vary across environmental gradients, rather, both slow and fast strategies persist amongst co-occurring species. High phylogenetic conservatism suggests early lineages of ants diverged in their economic strategies and subsequently diversified, locking in fundamental templates of investment and resource return. The remarkable similarities in economic strategies employed by ants and plants for resource acquisition and use suggest that there may be common principles underlying the rules of life.

Understanding the responses of organisms to environmental change is critical to tackling the grand challenges of 21st century biology. Fields such as ecophysiology and ecology have embraced these challenges and “re-invented” themselves in part by shifting the scale of scientific enquiry and utilizing large-scale comparative approaches. Behavioural research has not yet realized this potential to the same extent. In this paper, we argue that adopting a trait-based approach at large spatial, temporal and taxonomic scales can advance the field of behavioral ecology and address emerging questions in biology. We surveyed the literature in relevant ecology and behavior journals between 1981 and 2020 and found that ecological journals have changed markedly over time, specifically in their focus on understanding interspecific trait variation at broad taxonomic, spatial and temporal scales. This pattern is not apparent for animal behavior, where intra-specific and often intra-population scale of scientific enquiry has mostly been the focus over the last four decades. We argue that behavioral plasticity can be a critical first response to environmental change that might buffer or even lower the risk of extinction. To estimate the capacity of populations or species to respond to change behaviorally, we propose a comparative approach- spatially, temporally or taxonomically- that systematically captures variation in key traits with broad implications for conservation and community ecology. Further, we provide guidance in the methods and resources required to apply a trait-based approach to animal behavior.

Antarctica, long considered an environmental sanctuary, now confronts accelerating, complex and inter-related conservation challenges. The vast size and remote location of the continent introduce substantial uncertainty in understanding and predicting these threats. Here, using strategic foresight techniques, we synthesized insights from a global horizon scan with 131 experts from 42 countries. We identified ten emerging conservation challenges across six thematic categories. Key issues included extreme precipitation, emerging animal pathogens, human pandemics, security threats, reduced cooperation among Antarctic Treaty parties and potential agricultural expansion. Several of these challenges stem from persistent underlying drivers, revealing how longstanding processes are giving rise to new and increasingly acute conservation concerns. Others, driven by global disruptions, have no historical precedent in the region but increasingly constrain decision-making and international coordination. This horizon scan reveals substantial limitations in the ability of the Antarctic Treaty system to address these challenges, underscoring the need to reassess existing governance mechanisms to protect the unique ecosystems of Antarctica and its vital role in the global climate system.

Mosses play a key role in Antarctic ecosystems. Understanding of moss diversity and its likely drivers across Antarctica is, however, limited, as is the extent to which Antarctic Specially Protected Areas (ASPAs) represent this diversity. Both are important given changing climates and direct human impacts in the region. Here we investigate variation in moss diversity, the frequency distribution of their range sizes, and their continent-wide conservation. Richness is positively related to temperature, but negatively related to latitude, distance from bird colonies and geothermal sites; terrain roughness showed weak, yet positive, effects. Beta-diversity is similar to that found for assemblages separated by long distances, dominated by species turnover. Multi-site turnover (zeta diversity) suggests that niche-related mechanisms are likely more responsible for diversity patterns than neutral mechanisms, despite the significant role wind-driven dispersal is thought to play in structuring Antarctic biodiversity patterns. The frequency distribution of range sizes of mosses was right skewed, indicating that several moss species have very small range sizes, while a few species have larger ranges. Where ASPAs include mosses, richness varies between 1 and 41 species, with 65.1% (71 species) of the 109 species known from the continent included in the ASPA network. Twenty-four species lie within 25 km2 radius of an ASPA, and 14 species beyond this distance could be considered relatively more difficult to protect. These findings lend support to the proposal that changing temperatures and expanding ice-free areas will substantially increase Antarctica's diversity. Nonetheless, the mosses are reasonably well represented by the ASPA network, contrasting with other Antarctic taxa.