National University of Tierra del Fuego

The presence of exotic herbivores can have detrimental effects on insular ecosystems because it usually involves the introduction of a previously absent functional group. Understanding feeding behavior is crucial to manage potential impacts, as it provides valuable information on which species may be most susceptible to the actions of these herbivores. We estimated diet selection of introduced red deer (Cervus elaphus) and goats (Capra hircus) in western Isla de los Estados, Argentina. We conducted floristic surveys to assess plant composition and forage availability at the landscape level. We evaluated the diet of both ungulates through microhistological analysis of feces during two spring-summer seasons. Overall, we detected 44 plant taxa in their feces, representing 67.7% of the plant richness detected in the field. Diet composition was similar between species, including a wide range of vascular plants and two groups of non-vascular plants, though both were dominated by a few species of shrubs and forbs. Nonetheless, both species select grasses, predominantly found in marine tussock grasslands, and trees mainly found as seedlings and sapling in forests and stunted trees in wetlands. Our results suggest that the introduced species exhibit overlapping forage selection, possibly having negative synergic effects on forest and grassland regeneration. This is concerning as these grasslands are of great importance for seabirds’ reproduction. Our findings provide valuable information to develop management plans for the conservation of this unique island ecosystem.

Ocean warming and acidification challenge marine ectotherms with rapid, multiple and simultaneous environ­ mental changes. As knowledge of these impacts on fish from the sub-Antarctic is scarce, this study seeks to explore the combined effects of warming and acidification on the thermal and metabolic responses of Patago­ notothen tessellata and Harpagifer bispinis, two sympatric notothenioid fish from the Beagle Channel. Juveniles were exposed to present-day and near-future summer temperatures (~10 and 13 ◦C) and pCO2 levels (~500 and 1300 μatm) in a full factorial design. Their critical thermal minimum/maximum (CTmin/CTmax) were assessed and their partial thermal tolerance polygons were estimated. Oxygen consumption rates allowed us to calculate fish’ aerobic scope (AS) as the difference between the standard and maximum metabolic rates (SMR and MMR). The CTmin of both species were affected by temperature, pCO2 level and their interaction, while the CTmax of P. tessellata was affected by both factors and that of H. bispinis, only by temperature. The partial thermal tolerance polygon of P. tessellata significantly decreased with future pCO2 levels, while no changes were observed for H. bispinis. In P. tessellata, SMR and MMR were affected by temperature and pCO2 levels and the AS by their interaction. Conversely, H. bispinis showed no differences in SMR, MMR and AS under different conditions. The increase in SMR and decrease in AS of P. tessellata with future temperatures and pCO2 levels may explain the changes in its thermal tolerance, while for H. bispinis, either the species has a greater capacity to adapt its metabolic response to warming and acidification, or different physiological processes are responsible for the observed changes in its thermal tolerance. Overall, present information could be a valuable tool for forecasting shifts in habitat suitability across the distribution range of both species and other similar fish in the context of climate change.

Resumen A inicios de la década del setenta marxistas de diversas corrientes se lanzaron al estudio sistemático del estado. El debate alemán de la derivación del estado, que es el que aquí nos interesa, tendió puentes con el relativo al mercado mundial vis-a-vis a la problemática del imperialismo. En relación con el mercado mundial y el imperialismo se observó que era necesaria una comprensión más acabada del estado. Las investigaciones apuntaban a explicar, entre otros asuntos, al funcionamiento de la ley del valor, el proceso de acumulación y los tipos de cambio a escala del mercado mundial en función de la mediación de los estados (ALTVATER, 2017; OSORIO, 2019). En estos aportes estaba implícita una concepción del estado, pero el vínculo entre ambos fenómenos no había sido establecido. Claudia von Braunmühl (2017) asumió la tarea de establecer la relación interna entre mercado mundial y estados. Así, emprendió la tarea de derivar al estado a partir del mercado mundial, de este modo también buscaba explicar el fenómeno del imperialismo de manera crítica. En este contexto, Joachim Hirsch (2017) señaló que la relación intrínseca entre el fenómeno del imperialismo y el estado se hallaba en el proceso de acumulación. El trabajo de investigación empírica sobre Inglaterra de Simon Clarke (1988) resultó en una demostración histórica de la conexión entre acumulación, dominación, lucha de clases e imperialismo y mostró que este fenómeno estaba conducido por la crisis, ie. la lucha de clases (CLARKE, 1988). En las líneas que siguen continuaremos con esta empresa. Nuestro objetivo es establecer el vínculo lógico entre estado, mercado mundial e imperialismo. Mostraremos, entonces, que el imperialismo es una categoría intermedia tanto a nivel lógico como histórico. Señalaremos que supone un modo específico de articulación de lo económico y lo político a nivel global (orden histórico); implica un ordenamiento histórico del sistema internacional de estados y del mercado mundial que supone un modo de subordinación del trabajo mediado por la competencia (orden histórico); y, en este sentido, funge como ordenador del sistema jurídico internacional (orden lógico).

The elusive southern river otter (Lontra provocax; huillín in Spanish) is critically endangered in the Argentine portion of Tierra del Fuego, and low social awareness may be one of the major threats to its conservation. Our survey of local residents’ knowledge and valuation of the huillín showed that only 14% recognized photographs of the species, almost half did not know that it is endangered and most erroneously thought it was an introduced species. Greater knowledge about the huillín was related to higher respondent education levels. Younger and more knowledgeable residents valued the species more for ecological and relational reasons; its instrumental value was considered least important. More communication should be targeted at older people and groups not directly interacting with nature via informal education methods, including combining positive messages about the huillín and other native species with ongoing outreach efforts warning about biological invasions. Understanding perceptions and valuations of biodiversity can make conservation efforts more effective and inclusive.

The climate in southern Patagonia is heavily influenced by the Southern Westerly Winds (SWW). Therefore, climate reconstructions from this region are valuable for our understanding of the temporal dynamics in the atmospheric circulation of the Southern Hemisphere. In this study a sedimentary record from the shallow lake Laguna Amalia – located in the semiarid Fuegian steppe of Tierra del Fuego (53°S) – was used to study how the hydroclimate in this region has changed over the last ~7100 years. Our interpretations rely on a combination of pollen, diatoms, total organic carbon, carbonates, lithology and sediment accumulation rate, together with geomorphological features of the landscape. We conclude that before 6700 cal BP Laguna Amalia was a permanent water body. Around 6700 cal BP the climate becomes drier in response to stronger SWW, and from around 6000 cal BP the lake entered a semi-permanent state with variable salinity and prolonged drier periods. Between 3000 and 600 cal BP Laguna Amalia becomes a more permanent freshwater lake with only shorter periods with desiccation. For the last 600 years the climate has again become drier, and the lake is currently experiencing seasonal desiccation. These hydroclimatic changes can largely be attributed to the variable influence of the SWW, with weaker SWW allowing the advection of moist air masses from the east into northern Tierra del Fuego.

Fire is one of the most important disturbances of the earth‐system, shaping the biodiversity of ecosystems and particularly forests. Climatic change and other anthropogenic drivers such as deforestation and land use change could produce abrupt changes in fire regimes, potentially triggering transition from forests to savannah or grasslands ecosystems with large accompanying biodiversity losses. The interplay between climate change and deforestation might intensify fire ignition and spread, potentially giving rise to more extensive, intense, and frequent fires, but this is highly uncertain. We use a simple forest‐fire model to analyze the possible changes in the Amazon region's fire regime that depend on climate change‐related variables. We first explored the model behavior and found that there are two possible regime changes: a critical regime that implies high variability in fire extent and mega‐fires, and an absorbing phase transition which would produce the extinction of the forest and transition to a different vegetation state. We parameterize the model using remote sensing data on fire extent and temperature, and show that it demonstrates proficiency in predicting past fires. Upon considering 21st‐century climate projections and deforestation scenarios, our findings suggest that the Amazon region is not currently nearing any of these regime changes but predict a consistent increase in fire extent mainly induced by deforestation. Therefore, stopping deforestation could be an important factor in reducing the potential for drastic alterations in tropical forests of the Amazon region.

Aim To understand the influence of Andean uplifts and glacial cycles on South American biodiversity, we delve into the population genetics and evolutionary history of a unique subantarctic island raptor specialised in exploiting marine food webs. Location Islands in Tierra del Fuego and Malvinas/Falklands. Time period Last glacial period to the present. Taxon Phalcoboenus australis . Methods We used RAD sequencing to assess genetic diversity, population structure and to model demographic history through descriptive and hypothesis‐based evolutionary methods. Results We found evidence of two independent lineages: one inhabiting the Fuegian archipelago and the other one occurring in the Islas Malvinas/Falkland Islands, with the latter presenting higher genetic diversity and evidence of finer‐scale population structure. The best supported demographic scenario places the divergence time of these lineages during the last glacial period (ca. 50,000 years ago), with the occurrence of gene flow during the first 27,000 years after their divergence. Recent demographic modelling supports the general pattern of increasing genetic variability as landmasses were uncovered following the glacial period (i.e., the Fuegian archipelago) in contrast with a decrease in genetic diversity associated to island fragmentation (i.e., in the Islas Malvinas/Falkland Islands). Main Conclusions We propose that post‐glacial sea level rise and the subsequent isolation across the submerging Patagonian Shelf have driven population fragmentation and recent genetic structure in this species. Our findings advocate for recognising the two identified divergent lineages as distinct conservation units. We highlight the intricate interplay of ecological factors, glacial cycles and population dynamics in shaping the evolutionary trajectory of this unique and threatened raptor species in southern South America.

In 1946, 20 beavers ( Castor canadensis ) were introduced in Tierra del Fuego, Argentina, and over the last 70 years, the population has expanded, severely affecting riparian environments. In 2008, Argentina and Chile agreed to restore the environments affected by beavers through their eradication. The objectives of this paper were to assess the trapping effort and cost required to remove beavers, and to determine the factors that influence capture success. The study was conducted over 7 pilot areas in the Argentine part of Tierra del Fuego. Ten trappers using body‐grip traps, snares, and shooting carried out an eradication pilot project between October 2015 and June 2018. Trappers acted in 505 colonies, performing 9,751 trapping episodes, and capturing 1,012 beavers. In the mountain range zone, trappers needed on average 23 trapping episodes/km of watercourse. Capture success was best explained by trap placement and trap type. We estimated a required investment of 31 million US dollars over 17 years for a full beaver eradication in the Argentine part of Tierra del Fuego. We concluded that by using mainly body‐grip traps, eradication is feasible and it allows trapping in neighboring colonies simultaneously, without the need to check traps daily. Traps should be set preferably on dams, dams should be broken only after the first captures, and trappers should be trained to capture all individuals.

From a philosophical-political approach to culture isolated from the assumptions of a modern-colonial-capitalist space-time, this essay examines the production of diverse spatio-temporal regimes. Museums, as emergent products of the spatio-temporal device of modern exhibition, stress the tradition-transmission relationship. Tradition implies an operation of separation that sacralizes a territory and a historical narrative -even when shown as secularized- while unifying, stabilizing and hierarchizing the version of an abstract, absolute, progressive, linear space-time over multiple spaces and times which it intends to proscribe. This does not occur without an intrinsic relationship with transmission as a process that includes an impossible point of closure based on which the possibility of change, which tradition seeks to control, rests. Based on a case study of museification processes associated with the 100th Anniversary of the city of Río Grande (Tierra del Fuego, Antarctica and South Atlantic Islands, Argentina), this essay explores four spatio-temporal regimes, and identifies several operations (profanation, inoperability, others) dismantling the spatio-temporal hierarchies that fix tradition. In this sense, supplementation process as the thought of the alteration, that is, change in terms of event occurrence, stands out. Supplementation thus involves an emancipatory thought in action, which dismantles the hierarchies and inequalities in the processes of museification linked to modernity.

Intrinsic and extrinsic factors, such as bioerosion at nesting sites, regulate population dynamics and are relevant for the long-term conservation of penguins. Colony trends (between 2004–2022) were studied in a Magellanic penguin colony on Martillo Island, Beagle Channel, Argentina and compared between zones with contrasting degrees of erosion (high, medium, low). Individuals from each zone were characterized for foraging ecology, stress, and reproductive performance during the 2017–2018 breeding season to better understand the colony dynamics. Changes in nest abundance varied in magnitude between nesting zones with different characteristics of occupation time, density and erosion. Declines in nest abundance in the densest, most eroded and longest occupied zone suggests that environmental degradation may be limiting the colony’s carrying capacity. A higher percentage of late breeders (probably younger breeders) occupied the less eroded and more recently occupied zone. Foraging, breeding and stress barely differed between zones. New individuals recruiting into the breeding colony select less-eroded zones, either to reduce competition for nests or to avoid other effects of erosion and high-density areas. If this is the mechanism behind the shift in numbers throughout the island, we expect the island to be progressively occupied to the west. If competition or other density dependent factors are at play, a time will come when the vacant east side will begin to be recolonized by younger individuals. However, if erosion or other long-term effects spread throughout the island, recolonization may not occur and the colony may ultimately be abandoned as individuals search for new breeding grounds. Erosion at the breeding site may be a key factor in regional population trends of this burrow nesting species, by following an extinction / colonization of new sites process.

As global biodiversity is rapidly declining due to habitat loss, it is important to determine how to protect it. The policies of many conservation agencies are still prioritizing the preservation of a single large habitat area (SL) versus several small areas of the same size (SS), despite empirical support favouring SS. However, to date, while many studies have explored this issue using model communities, the results are mixed. In competitive community models, fragmentation has a negative effect at low habitat amounts, whereas neutral community models suggest positive effects. This work aims to explore spatial multispecies models to verify the SS > SL pattern and determine its causes. We used three types of models: a classical neutral, neutral with habitat selection and a competitive hierarchical model. All models have three parameters, namely extinction, reproduction and dispersal distance. In the classical neutral model, species are equivalent and have the same parameters; when there is a reproduction event, they send the propagule to a surrounding patch blindly, and if the patch is already occupied, the propagule dies. In the neutral with habitat selection model, the propagules select an empty patch, so their survival is ensured. In the hierarchical model, species have competitive dominance and more dominant ones can replace the less dominant with a replacement rate parameter. We use 100 species and start simulating the colonization of an empty area; then, we destroy a fixed amount of habitat using different regular patch sizes. The results for all models are almost always that SS retains more species than SL. The extinction of species in patches depends on the quotient between reproduction and extinction rates in relation to patch size. The only case when SL > SS is when dispersal is insufficient to connect patches, and patch size is smaller than the minimum to prevent extinction. If patch size is above the critical size to maintain local populations, the SS > SL pattern is due to the sampling effect of aggregated species distribution combined with the reduction of dispersal ability of species. High‐dispersal rates produce the homogenization of species distribution and a reduction of species richness and this is why habitat fragmentation by habitat loss retains more species when patches are smaller. The model predicts that if a set of species have more dispersal capabilities, the SS effect would be lower than for species with less dispersal. Read the free Plain Language Summary for this article on the Journal blog.

Subantarctic Nothofagus forests are the southernmost forests in the world, with negligible atmospheric nitrogen (N) deposition. Most paradigms about the role of ectomycorrhizal (ECM) fungi in N cycling and plant N uptake at high latitudes have been tested in boreal coniferous forests, while in the southern hemisphere, ECM hosts are primarily angiosperms. Using ITS1 meta‐barcoding, we characterized ECM and saprotrophic fungal communities in evergreen and deciduous Nothofagus forests forming monodominant and mixed stands in the archipelago of Tierra del Fuego (Chile and Argentina). We assessed the N economy of Nothofagus by correlating host species with fungal relative abundances, edaphic variables, net N mineralization, microbial biomass N and the activity of eight extracellular soil enzymes activities. The N economy of deciduous N. pumilio forests was strikingly similar to boreal coniferous forests, with the lowest inorganic N availability and net N mineralization, in correlation to higher relative abundances of ECM fungi with enzymatic capacity for organic N mobilization (genus Cortinarius). In contrast, the N economy of evergreen N. betuloides forests was predominantly inorganic and correlated with ECM lineages from the family Clavulinaceae, in acidic soils with poor drainage. Grassy understory vegetation in deciduous N. antarctica forests likely promoted saprotrophic fungi (i.e., genus Mortierella) in correlation with higher activities of carbon‐degrading enzymes. Differences between Nothofagus hosts did not persist in mixed forests, illustrating the range of soil fertility of these ECM angiosperms and the underlying effects of soil and climate on Nothofagus distribution and N cycling in southern Patagonia.

Scientists and managers seek to implement more inclusive and effective conservation strategies by incorporating plural valuations of nature and nature’s contributions to people (NCP) into research and decision-making. For Argentina’s threatened Espinal ecoregion, this need is particularly acute. In Entre Ríos province, practically all of these forests are devoted to production, and the expanding agricultural frontier increases their conversion to crops. We surveyed family ranchers and agricultural/environmental specialists, two key stakeholders for managing Espinal forests used for cattle grazing. Employing a sociocultural valuation, we determined i) stakeholder recognition of the Espinal’s NCP and its support for quality of life, ii) similarity between stakeholder valuations (importance: 0 = none; 4 = very) of NCP and dimensions of well-being derived from the Espinal, and iii) relationship between ecological (e.g., forest degradation) and social (e.g., place of residence) factors and perceptions of the forest. Ranchers recognized more NCP and quality-of-life aspects, and the importance to their well-being tended to be greater than specialists. Both groups valued regulating and non-material NCP above material contributions and considered that forests are very important for physical and mental health. Finally, only rancher perceptions varied with tested variables, depending on degradation levels of forests with which they have the most contact and/or carry out their activities, the number of uses and recreational activities they carry out in forests, their knowledge of forests, and their place of residence. This study illustrates common ground upon which to promote synergies between production and conservation in Espinal-cattle agroecosystems.

Purpose Universities strategically organize themselves around sustainability, including transformative goals in teaching and learning. Simultaneously, the role of online education has become more prominent. This study aims to better understand the purpose and process of creating online sustainability education (OSE) and to identify challenges and opportunities for implementing these courses and programs to achieve universities’ broader transformative sustainability goals. Design/methodology/approach This study uses a multiple case study design to research three universities in diverse geographical and institutional contexts (Finland, the USA and Colombia). Qualitative data was collected by interviewing program-related experts (n = 31) and reviews of universities’ strategic documents. Findings The findings suggest that despite important advances, further attention is merited regarding aligning the purpose of OSE with student learning outcomes, clarifying the values underlying the process of online program/course creation and developing transformative and process-oriented approaches and pedagogies to implement OSE. The authors also highlight emerging challenges and opportunities in online environments for sustainability education in different institutional contexts, including reaping the benefits of multilocality and diverse student experiences regarding sustainability issues. Originality/value There is a paucity of studies on university-level sustainability education in relation to online environments. This research expands on the existing literature by exploring three different geographical and institutional contexts and shedding light on the relationship between the practical implementation of OSE and universities’ broader sustainability goals.

In Tucumán, environmental scientists and authorities have long considered river pollution caused by the sugar industry to be a priority issue for research and management. However, little is known about how local communities perceive and relate to this issue and these environments. To obtain a more comprehensive understanding, we conducted 401 surveys in four localities to investigate the social perceptions of rivers affected by the sugar industry, utilizing the Drivers-Pressures-State-Impact-Response (DPSIR) framework to structure this sociocultural assessment. There was a broad recognition of rivers’ importance by 87% of respondents, but 44% reported that they do not visit them, reflecting a disconnect with these environments. Additionally, the community conceives rivers in “good condition” (state) based mostly on aesthetic aspects of the water, rather than health or ecosystem considerations. Overall, rivers were perceived negatively; problems (drivers, pressures) were perceived more than contributions (impacts). Although most (56%) respondents identified sugar industry pollution as “very important,” it ranked third, after other environmental and social pressures. Contributions of rivers that impact people’s well-being were valued lower, and only construction materials, water for animals, recreational spaces, and food were considered “somewhat important.” The majority (> 65%) did not identify rivers as important for energy generation or drinking water. Finally, 42% of the community was unaware of existing environmental public policies aimed at addressing river degradation. These social perceptions of Tucumán’s rivers and their management reveal both similarities and differences between expert-driven, ecological knowledge and society’s relationships with these rivers.

To effectively address ecosystem health risks, it is crucial to use detection methods that efficiently cover vast areas with good spatial resolution. These methods should enhance understanding of how phytoplankton blooms might evolve due to climate change. Satellite Ocean Color sensors are advantageous for detecting and monitoring phytoplankton blooms over time. This study uses the Inherent Optical Properties (IOP) index, which considers light absorption by phytoplankton (Ab_phy) and by detritus plus colored dissolved organic matter (Ab_adg), to detect phytoplankton blooms in six subareas within the San Matías Gulf (SMG; Patagonia, Argentina). The findings reveal a significant increase in bloom alerts over the last 20 years in the northwestern and southwestern subareas. Temporal changes in chlorophyll a (Chla) and sea surface temperature (SST) were observed, both showing an increase over the studied period. Environmental features like the diffusive attenuation coefficient (Kd_490) and Ab_phy also showed positive trends in four of the six subareas. The positive trends in SST and Kd_490 suggest a potential reduction in the euphotic zone depth. Additionally, the presence of phytoplankton biomass, indicated by Chla and Ab_phy, is linked to reduced light penetration in the water column due to absorption by the cells and self-shading. A decrease in Ab_adg was observed, while photosynthetically active radiation (PAR) showed no significant trend over the last two decades. These patterns could significantly impact the frequency and timing of phytoplankton blooms, altering their community composition and phenology. Such changes have profound implications for the entire marine food web and the ecosystem services within the SMG. The results underscore the importance of incorporating optical data for monitoring phytoplankton blooms across multiple areas.

In the Southern Atlantic Ocean, asteroids are abundant among the benthic taxonomic groups. The development patterns include a pelagic larva (planktotrophic/lecithotrophic), or a retained larva (internal/oral retention). The main objective was to revise the Asteroidea species composition from the Southern Atlantic (including marine protected areas) and to study their development patterns in relation to environmental conditions. Information was compiled from oceanographic surveys, scuba diving, and the GBIF database. Four species have extended their distribution. The Isla de los Estados island (SIE) and Namuncurá/Burdwood Bank II Marine Protected Area (N MPA II) are separated as independent clusters. SIE would be functioning as a geographical barrier, and N MPA II presents deep sea species. Namuncurá/Burdwood Bank Marine Protected Area (N MPA) presented a majority of protected development species, while in the Beagle Channel, most registered species presented free-planktotrophic larvae. Species with free-planktotrophic larvae and oral brooding strategies are more likely in shallower waters, while internal brooding species occur in deeper waters. Species with free-lecithotrophic larvae are more probable in middle depths, below the euphotic layer. These results are expected to make a valuable contribution to better understanding the general distribution and development patterns of Asteroidea from subantarctic waters, a group of organisms that are top predators of benthic communities.

The polar regions are increasingly at the center of attention as the hot spots of climate crisis as well as tourism development. The recent IPCC reports highlight several climate change risks for the rather carbon-intensive and weather-based/dependent polar tourism industry in the Arctic and the Antarctic. This study presents the scholarly state-of-knowledge on tourism and climate change in the polar regions with a literature survey extending beyond the Anglophone publications. As a supporting tool, we provide a live web GIS application based on the geographical coverages of the publications and filterable by various spatial, thematic and bibliographical attributes. The final list of 137 publications indicates that, regionally, the Arctic has been covered more than the Antarctic, whilst an uneven distribution within the Arctic also exists. In terms of the climate change risks themes, climate risk research, i.e. impact and adaptation studies, strongly outnumbers the carbon risk studies especially in the Arctic context, and, despite a balance between the two main risk themes, climate risk research in the Antarctic proves itself outdated. Accordingly, the review ends with a research agenda based on these spatial and thematic gaps and their detailed breakdowns.