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We assessed temporal variability in phytoplankton biomass, Chlorophyll a, nutrient availability, Gross Primary Production (GPP), community respiration (CR), and bacterial secondary production (BSP) over a year of monthly observations (October 2007 to October 2008) at a fixed station in the Puyuhuapi fjord, Chilean Patagonia (44°S, 73°W). A set of in situ observations gathered over two consecutive spring-summer seasons, and one autumn-winter season in the middle, has made it possible to connect the two-phase (i.e. productive season/non-productive season) pattern of Chlorophyll a (Chl a) variability shown by satellite data with a two-phase cycle in GPP, CR, and the composition of phytoplankton assemblages. Estimates of annual GPP and CR, integrated over the top 20 meters of the water column, were 533 and 537 g C m-2 yr-1, respectively. Low values of pCO2 were measured in mixed layer autotrophic waters (GPP/CR>1) while high pCO2 levels were measured in mixed layer heterotrophic waters (GPP/CR<1). Bacterial Secondary Production (BSP) was significantly and positively correlated with GPP (r = 0.6, p < 0.05, n = 24) and Chl a (r = 0.4, p < 0.05, n = 24) on an annual cycle basis. The winter drop in bacterioplankton (both bacteria and archea) activity (from 0.9±0.6 g C m-2 d-1 to 0.6±0.3 g C m-2 d-1) was not as pronounced as the winter drop in phytoplankton activity (from 1.1±1.12 g C m-2 d-1 to 0.1±0.09 g C m-2 d-1). It is hypothesized that dissolved organic matter (DOM) of terrestrial origin plays an important role (especially in winter) supporting bacterial activity in the Puyuhuapi fjord. [ABSTRACT FROM AUTHOR]

Ombrotrophic bogs in southern Patagonia have been examined with regard to paleoclimatic and geochemical research questions but knowledge about organic matter decomposition in these bogs is limited. Therefore, we examined peat humification with depth by Fourier Transformed Infrared (FTIR) measurements of solid peat, C/N ratio, and δ13C and δ15N isotope measurements in three bog sites. Peat decomposition generally increased with depth but distinct small scale variation probably caused by environmental changes occurred. C/N ratios varied mostly between 40 and 120 and were significantly correlated (R² > 0.55, p < 0.01) with FTIR-derived humification indices. The degree of decomposition was lowest at the site with the least sea spray input, while the peat was most decomposed at the driest site with highest sea spray deposition. Decomposition of peat was also advanced near ash layers. Values of δ13C were 26.5 ± 2‰ in the peat and partly related to decomposition indices, while δ15N in the peat varied around zero and did not consistently relate to any decomposition index. Concentrations of DOM partly related to C/N ratios, partly to FTIR derived indices. DOM was enriched in 13C and in 15N relative to the solid phase probably due to multiple microbial modifications and recycling of N in these N-poor environments. In summary, paleoclimatic signals may have influenced decomposition according to depth profiles of C/N ratios, δ13C values, and FTIR spectra, but the study also suggests that decomposition was also influenced by ash layers, sea spray input and other site specific factors. [ABSTRACT FROM AUTHOR]

Sphagnum peatlands are important ecosystems in the methane cycle. Methanotrophs living in and on the Sphagnum mosses are able to act as a methane filter and thereby reduce methane emissions. We investigated in situ methane concentrations and the corresponding activity and diversity of methanotrophs in different Sphagnum dominated bog microhabitats. In contrast to the Northern Hemisphere peat ecosystems the temperate South American peat bogs are dominated by one moss species; Sphagnum magellanicum. This permitted a species-independent comparison of the different bog microhabitats. Potential methane oxidizing activity was found in all Sphagnum mosses sampled and a positive correlation was found between activity and in situ methane concentrations. Substantial methane oxidation activity (23 µmol CH4 gDW-1 day-1) was found in pool mosses and could be correlated with higher in situ methane concentrations (>35µmol CH4 l-1 pore water). Little methanotrophic activity (<0.5µmol CH4g DW-1 day-1) was observed in living Sphagnum mosses from lawns and hummocks. Methane oxidation activity was relatively high (>4 µmol CH4 gDW-1 day-1) in Sphagnum litter situated at depths around the water levels and rich in methane. The total bacterial community was studied using 16S rRNA gene sequencing and the methanotrophic communities were studied using a pmoA microarray and a complementary pmoA clone library. The methanotrophic diversity was similar in the different habitats of this study and surprisingly comparable to the methanotrophic diversity found in peat mosses from the Northern Hemisphere. The pmoA microarray data indicated that both alpha- and gammaproteobacterial methanotrophs were present in all Sphagnum mosses, even in those mosses with a low initial methane oxidation activity. Prolonged incubation of Sphagnum mosses from lawn and hummock with methane revealed that the methanotrophic community present was viable and showed an increased activity within 15 days. The high abundance of methanotrophic Methylocystis species in the most active mosses suggests that these might be responsible for the bulk of methane oxidation. [ABSTRACT FROM AUTHOR]

Landscapes are shaped over time by the changing imaginaries that result from new representations of nature and the value associated with it. This paper discusses the evolving discourses which have shaped the perception of the landscape in two socially and ecologically significant contexts in Chile. The first is the central-southern region of the country, a large portion of which is now devoted to commercial forestry plantations. The second is the Patagonia-Aysén region, where since the 1990s, colonization of a land defined by a tradition of livestock rearing has evolved into a process epitomized by the slogan “Aysén, Life Reserve.” The representation that was made of central-southern Chile in the 50' and 60' as a deforested and degraded land was the justification for promoting a new form of land occupation: the monoculture forest, designed and executed by a specific law. Forty years on from the passing of this law, the plantations of central-southern Chile have undergone a process of naturalization. In this case, the exaltation of nature has been permanent (before and after the changes doing by this law). The only thing that changes is the definition of nature, which ended up including forest plantations. That is, discourses influence perceptions and these lead to new practices in the study area and beyond. In Patagonia-Aysén, by the other side, there has been a marked shift in the rhetoric surrounding land. This has been particularly noticeable in the case of government bodies and private ecotourism companies, which have constructed an imaginary in line with a new model of economic development for the area. In a break with tradition, both the public and private sectors are beginning to shift their investment away from agricultural and livestock exploitation and toward ecotourism and conservation projects. In both cases, we analyse the manner in which transformations in perceptions and representations of landscape bring about new forms of land use, and how new focuses of value and social interest, forged within wider environmental discourses, have brought with them unexpected social consequences, like depopulation, economic transformations, cultural changes, etc. Thus, the aim of this work is to expose and discuss the reality and scope of new green discourses and their influence on the perception of natural landscapes in the Chilean neoliberal context. [ABSTRACT FROM AUTHOR]

For thousands of years, hunter-gatherer societies from southern and central Patagonia inhabited a Subantarctic landscape. In this paper, we argue against the traditional assumption that these were simple societies. We examine population diversity from ecological, archaeological, and ethno-historical data sources, emphasizing the economic and social variability while considering social change through time. We end by analyzing processes of the development of social complexity and hierarchy in recent times, when the industrial world violently disarticulated those societies. All this evidence suggests levels of social variability and complexity archaeologists have not expected. The paper critically reviews traditional archaeological approaches and suggests new research lines that allow for a better understanding of social dynamics. [ABSTRACT FROM AUTHOR]

Holocene environmental changes in Patagonia were mostly shaped by fluctuating ice cover recession. Consequently, environmental reconstructions are largely based on discontinuous moraine chronologies from valley deposits. Here, we present a 3 m long continuous sediment record recovered from Laguna Meseta (LME), a lake located on Meseta Chile Chico. Its altitude and location relative to the North Patagonian Icefield provide a unique opportunity to reconstruct the glacial history and related environmental dynamics. Our radiocarbon chronology constrains sedimentation to the last ∼10000 years and provides a minimum age for postglacial ice-free lacustrine conditions, due to a westward retreat of the ice cap. Lacustrine productivity reached its maximum at the start of the lake phase and decreased afterwards. Between 5500 and 4600 cal yr BP, a major shift towards allochthonous sediment accumulation occurred, caused by an abrupt increase in clastic deposition from basaltic lithologies of the Meseta Chile Chico. This episode correlates with the precipitation-driven Mid-Holocene glacier advance of Patagonian glaciers and suggests that conditions were colder and/or wetter on Meseta Chile Chico at that time. After 4600 cal yr BP, these conditions continued to supply LME with clastic sediments until a stepped decrease around 900 cal yr BP. Thereupon, lacustrine productivity distinctly increased and stabilized around 300 cal yr BP. Our findings indicate that changes in sedimentation on Meseta Chile Chico were mainly controlled by regional variability in the precipitation. Furthermore, strong correlation between our records and available proxies for oscillations of the Southern Hemisphere Westerly Winds suggest a pronounced climatic control by this prominent wind system for central west Patagonia during the last 10 000 years. [ABSTRACT FROM AUTHOR]

This article contrasts whether the sectors with a GDP close to the average contribute more to the economic system through their employment multipliers and/or dispersion effects than those with a higher GDP. To achieve this, an 11-year horizon (2008-2018) and the 11 main centers of Chile's macro territories [Norte Chico (6) and Patagonia (5)] are used as a reference. The input-output matrices are used as source of information from which the variables GDP, employment multiplier and dispersion coefficients are obtained, the latter understood as those that allow quantifying the scope of the repercussions of an economic activity, by means of its direct and/or indirect effects. The results allow us to conclude that economic activities with a GDP close to the average, such as that of the education sector, show diffused effects that support the idea of facilitating development through changes in their production versus others that, with high GDPs, show concentrated effects that therefore limit their contribution in terms of interaction. These results will contribute to the establishment of economic development policies according to the particularities of each territory. [ABSTRACT FROM AUTHOR]

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Copyright of Revista Espanola de Antropologia Americana is the property of Universidad Complutense de Madrid and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The lowering of global sea level during the Pleistocene by more than 100 m and subsequent inundation of coastal areas constitutes a problem in terms of general research on early maritime-oriented societies. However, post-glacial isostatic rise in glaciated regions has produced raised shorelines of Late Pleistocene/Early Holocene age, e.g., in Scandinavia, Patagonia, and North America. As these regions contain the oldest preserved coastal areas, they are imperative for the understanding of the development of maritime hunter-gatherers. The extensive Norwegian coastline appears to have been colonized in the course of the few hundred years around 9500 cal B.C. An overwhelming majority of Early Holocene sites are found in the fiord/skerry coastal landscape, indicating that marine resources were vital in the subsistence pattern of people occupying the region. The lithic tradition is clearly linked to specialized megafauna hunters in the continental plains (the Ahrensburgian complex of northwestern Europe), but the facts about and dynamics of the development of the marine subsistence pattern are unclear. This paper focuses on this problem-with comparative perspectives towards the emergence of maritime foragers in Patagonia. [ABSTRACT FROM AUTHOR]

Patagonia and Tierra del Fuego include contrasting environments and populations. Both were settled more than 10,000 years ago, although the coastal resources were not intensively exploited until four millennia later. The littoral resource exploitation had very different characteristics on the Atlantic compared to the Magellan-Fuegian coasts. Generalized strategies were maintained in the former, while in the latter the inhabitants developed a specialization—they became intensively dependent on the littoral and marine resources and designed special technological means for their procurement and processing, including navigation capability. This process began some 6,400 radiocarbon years ago and these sea-nomads colonized the southern- most archipelago from the Beagle Channel down to Cape Horn. After synthesizing the settling of Patagonia, this paper focuses on the process of colonization and cultural endurance of the seanomads until the time of European contact. [ABSTRACT FROM AUTHOR]

The south of Patagonia is characterized by its semi-arid weather and numerous small, temporary and permanent shallow ponds. The aquatic crustaceans of these water bodies are characterized by their endemism and species richness. The present study was done in the surroundings of Punta Arenas (53°S, Chile), and included six shallow ponds. Samples for conductivity, total dissolved solids, chlorophyll, and crustacean zooplankton as well as littoral species of crustacea were collected. Our study revealed that Branchinecta gaini Daday, 1910 occurred at low conductivity (0.55 mS/cm), and low total dissolved solids (0.28 g/l) and chlorophyll (2.70 μg/l) concentrations, such compared to sites without fairy shrimp populations, that had significantly high conductivity (3.58 mS/cm), and high total dissolved solids (1.80 mg/l) and chlorophyll (12.80 μg/l) concentrations. The results partially agree with the first descriptions of Patagonian water bodies that indicated the presence of fairy shrimps in low conductivity waters. The observations of the presence of B. gaini and other associated microcrustaceans are similar to descriptions of unpolluted water bodies in Antarctica, and those results would support the observations of the present paper. Other reports on fairy shrimp habitats mentioned a wide range of both salinity and trophic status. Other ecological and biogeographical topics on fairy shrimps are also discussed. [ABSTRACT FROM AUTHOR]

Background: I review the natural history of the tuco-tuco Ctenomys magellanicus in Patagonia and Tierra del Fuego, southernmost geographic regions shared by Argentina and Chile. By natural history I mean both historical records and ecological features of this gregarious burrowing rodent. Methods and results: I conducted a selective review of the natural history of C. magellanicus, as recorded in mainstream journals and proceedings, landmark monographs and books, and internet sources. I report results on: (a) Original description, (b) Diversity and distribution, (c) Life history, (d) Interactions with plants and herbivorous competitors, (e) Interactions with predators other than humans, (f) Interactions with humans, and (g) Abundance and conservation. I also enter the anthropology field, but I only touch the archeology field. Although this review is not on the systematics of C. magellanicus, I do provide an updated overview of the phylogenetics-based taxonomy of the genus where it belongs. Discussion: There is a rather large body of literature on C. magellanicus, comprising the fields of anthropology, archeology, biogeography, biology, ecology, and systematics. These areas are broadly covered but thinly treated, offering interesting opportunities for further research. For instance, on adaptation, evolution, and environmental impact of the southernmost burrowing rodent in the world and its cultural impact on vanishing native peoples, especially the Selk'nam. [ABSTRACT FROM AUTHOR]

Haematocrit, the proportion of blood comprising erythrocytes, is often used as a proxy of individual condition. Nestling haematocrit is influenced by several factors but ambient temperature is generally agreed as a key driver. It is unclear which day(s) in embryonic or nestling development are most influential in determining pre‐fledgling haematocrit. This is important, because if we are able to identify what day(s) nestlings are physiologically most vulnerable to climatic conditions, this may inform future conservation management and help mitigate the effects. We investigated the effect of ambient temperature, precipitation, body size, brood size, age, food abundance and habitat on nestling haematocrit in Aphrastura spinicauda (thorn‐tailed rayaditos). We collected this data from two climatically different locations in Chile: northern Patagonia (Pucón) and Sub‐Antarctic Patagonia (Navarino Island), located ~ 1800 km further south. We aimed to identify the key drivers of nestling haematocrit and find when nestlings are physiologically most vulnerable to climatic conditions. We confirm that ambient temperature is the key driver of nestling haematocrit, with increasing ambient temperatures nestling haematocrit decreased. However, precipitation also affected haematocrit in the late incubation stage. At low and high precipitation, nestling haematocrit was low and is optimum in light rainfall. Our results show a delayed effect of ambient temperature and precipitation in late incubation and on the day of hatching which can determine pre‐fledgling haematocrit, which may cause lower post‐fledgling fitness. We found that climatic conditions on the day haematocrit was collected was not important in determining haematocrit. We found that haematocrit was higher in the sub‐Antarctic area and that higher temperatures and precipitation on the day of hatching will result in lower nestling haematocrit and poorer pre‐fledgling condition. As atmospheric temperatures rise, nestling fitness is at risk. This is a threat to many bird species, especially those in locations vulnerable to climate breakdown. [ABSTRACT FROM AUTHOR]

Coastal dolphins and porpoises such as the Chilean dolphin (Cephalorhynchus entropia), the Peale's dolphin (Lagenorhynchus australis), and the Burmeister's porpoise (Phocoena spinipinnis) inhabit the remote areas of Chilean Patagonia. Human development is growing fast in these parts and may constitute a serious threat to such poorly known species. It is thus urgent to develop new tools to try and study these cryptic species and find out more about their behavior, population levels, and habits. These odontocetes emit narrow-band high-frequency (NBHF) clicks and efforts have been made to characterize precisely their acoustic production. Passive acoustic monitoring is a common way to study these animals. Nevertheless, as the signal frequency is usually higher than 100 kHz, storage problems are acute and do not allow for long-term monitoring. The solutions for recording NBHF clicks are usually twofold: either short duration, opportunistic recording from a small boat in presence of the animals (short-term monitoring) or long-term monitoring using devices including a click detector and registering events rather than sound. We suggest, as another possibility, medium-term monitoring, arguing that today's devices have reached a level of performance allowing for a few days of continual recording even at these extremely high frequencies and in difficult conditions, combined with a long-term click detector. As an example, during 2021, we performed a quasi-continuous recording for one week with the Qualilife High-Blue recorder anchored in a fjord near Puerto Cisnes, Region de Aysen, Chile. We detected more than 13,000 clicks, grouped in 22 periods of passing animals. Our detected clicks are quite similar to precedent results but, due to the large number of clicks recorded, we find a larger variability of parameters. Several rapid sequences of clicks (buzz) were found in the recordings and their features are consistent with previous studies: on average they have a larger bandwidth and a lower peak frequency than the usual clicks. We also installed in the same place a click detector (C-POD) and the two devices compare well and show the same number and duration of periods of animals presence. Passages of odontocetes were happening on average each three hours. We thus confirm the high site fidelity for the species of dolphins emitting NBHF clicks present in this zone. Finally, we confirm that the combined use of recording and detection devices is probably a good alternative to study these poorly known species in remote areas. [ABSTRACT FROM AUTHOR]

Background: Deer species play an important role in the enzootic cycles of several Anaplasma species. While in the Northern Hemisphere ticks of genus Ixodes are well recognized vectors of these intracellular bacteria, less is known regarding the biological cycles of Anaplasma spp. in South America. Methods: Using PCR protocols and Sanger sequencing, we assessed the presence of Anaplasma spp. in blood and ticks collected on a native deer species (Pudupuda) from southern Chile. Results: Based on phylogenetic analyses of the 16S rRNA, gltA and groEL genes and calculation of average sequence divergence for groEL, our results bring to light a novel genovariant of Anaplasmaphagocytophilum (named strain "Patagonia"). The strain represents a novel ecotype within the A. phagocytophilum species complex and was detected in both P.puda and their ticks. Using a larger matrix, denser taxon sampling and outgroup, our maximum-likelihood- and Bayesian-inferred phylogenies for groEL provide an accurate picture of the topology of A. phagocytophilum ecotypes and their evolutionary relationships. Conclusions: This is the first report of an ecotype of A. phagocytophilum in South America. Our results provide novel insight into the genetic diversity and ecology of this complex of bacterial lineages. Further studies should elucidate the enzootic cycle of A. phagocytophilum strain "Patagonia" and assess its pathogenic potential for pudues, domestic animals and humans in the region. [ABSTRACT FROM AUTHOR]

Recent literature on commodity frontiers and resource-based economies has reopened the debate surrounding the effects of extractive economies on people's connection to a political system that sustains predominant modes of production. However, the debate has focused on struggles and broader political tensions between social movements and private companies or the State. The present article adopts a different approach, reflecting on the emergence of distinct forms of citizenship in rural territories. Through examining the salmon industry in the Los Lagos region of Chile, I identify connections between commodity production, place-based identity politics, and citizenship performance. I argue that the concept of rural citizenship understood here as the set of practices of relating to the state grounded in a rural sense of belonging and assessment of the place rural areas have in the frontier project is central to understanding political participation in commodity regions and is informed by the trialectic relationship between place identity, commodity production, and the democratic institutions in place. The article concludes with an invitation for further research into frontier politics from a commodity perspective. [ABSTRACT FROM AUTHOR]

Copyright of Prohistoria is the property of Prohistoria Ediciones and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article investigates different forms of registry of the Mapuche concept in both Chile and Argentina after indigenous territories of Araucania and Patagonia were conquered, by late XIX century. A hypothesis is suggested concerning a difference in this registry, based on what was -within these contexts- the destination of Mapuche bodies on the one hand and of papers and documents created and accumulated by these populations before being included into both Sates sovereignties, on the other. We can see that in Argentina, bodies museographical inscription was privileged and, at the same time there was a document archives inscription which made Mapuche an historiographical and anthropological past element and lacking political validity at present. While in Chile, there is a population inscription of Mapuche bodies related to a kind of mestizo and state ideology through which the Mapuche concept got a kind of racial validity. This is how the idea of "reducto" arose as a category through which ambivalences from both types of inscription are analyzed so that the Mapuche concept has worked as a patrimonial capital of national sovereignty (associated to identity and autochthonousness) or, on the contrary as just the rest of a life or indigenous culture that persists and is managed in the political and historical limits of this same national sovereignty. [ABSTRACT FROM AUTHOR]

This paper describes a simulation model combining the main components of water balance and growth of perennial grassland steppe in Chilean Patagonia, to estimate long-term annual production (Yr, kg ha-1) and sheep carrying capacity (GC, sheep equivalent [EO] ha-1). The model is based on climate-water balance relationships, where the basic process is evapotranspiration. The model calculates Yr depending on the accumulation of transpiration and the water use efficiency from the time of growth initiation until the grassland accumulates the maximum amount of dry matter (DM). Depending on Yr, the DM requirement of EO, the proper use factor of grassland and a slope correction factor, a range site GC is calculated. Simulations were performed using actual climate data sets of eight growing seasons at Kampenaike (52°41' S; 70°54' W; 12 m.a.s.l.) and a long-term simulation in the same location, using a stochastic weather variables generator. Through the model it was possible to estimate the water loss associated with the components of water balance and estimate the restriction imposed by water deficit on Yr. By simulating many years, it was possible to establish a normal distribution of GC with 0.629 EO ha-1 yr-1, associated with 80% probability of being exceeded, which is lower than values reported in field assessments. This method calculates GC with a conservational approach, taking into account soil and climatic variability in semiarid ecosystems. [ABSTRACT FROM AUTHOR]

In this paper, transformations of internal links within the indigenous political field are explored, focusing on the last decades of the frontier. This period, in which the state progresses towards its political unification and institutional consolidation, state policies regarding Indian people show a more unified profile and aim to create the conditions necessary for the frontiers advance. The peace treaties policy, extended to almost the whole indigenous map, will be one of the devices through the state will attempt to canalize and to order its relations with different chiefs and groups. Our interest attempts to identify the probable conditionings and influences of this policy on the indigenous population at the conformation, strengthening and weakening of their political alliances. We intend specifically to reconstruct-within this context-the process of the Calfucurá's leadership, to identify the impact of state interventions over the extent of his political summoning capacity during this period. [ABSTRACT FROM AUTHOR]

Copyright of Botanical Review is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The southernmost portion of the Liquiñe-Ofqui fault zone (LOFZ) lies within the proposed slab window which formed due to oblique subduction of the Chile Ridge in Patagonia. Mapping of paleo-surface ruptures, offsets, and lithological separations along the master fault allowed us to constrain geologic slip rates for the first time with dextral rates of 11.6–24.6 mm/year (Quaternary) and 3.6–18.9 mm/year (Late-Cenozoic) respectively. We had trouble mapping the LOFZ in one local because of a partially collapsed and previously undiscovered volcanic complex, Volcan Mate Grande (VMG: 1,280 m high and thus Vesuvius-sized) that grew in a caldera also offset along the LOFZ and has distinct geochemistry from adjacent stratovolcanoes. Besides the clear seismic and volcanic hazard implications, the structural connection along the main trace of the fast slipping LOFZ and geochemistry of VMG provides evidence for the slab window and insight into interplay between fast-slipping crustal intra-arc crustal faults and volcanoes. [ABSTRACT FROM AUTHOR]

Ecotonal zones between eastern semi-arid steppes and Nothofagus spp. forests in western Patagonia are the result of broad ecosystem changes, which have intensified in the last 140 years. Our objectives were to determine historical changes in land use, land cover, and forces driving such changes in Nothofagus ecosystems in the Río Verde district in southern Chile, to support future management recommendations. This interdisciplinary study used historical records including scientific and military expeditions, Landsat imagery, and other archival sources. Forest cover changed radically between the late nineteenth and mid-twentieth centuries, from subsistence use by indigenous peoples, to forestry and livestock industries. The main driving forces of landscape change have been anthropogenic forest fires, logging, exotic pasture establishment, and mining. Future perspectives suggest that conserving the cultural values and natural resources of this region will depend on ecologically sound landscape planning, reversing forest fragmentation, restoring riparian corridors, and preserving indigenous archaeological sites. [ABSTRACT FROM AUTHOR]

Copyright of Revista del Museo de Antropología is the property of Museo de Antropologia - IDACOR and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Several plant species have the potential to facilitate the presence of other plant species in the community, and yet most of our knowledge on this phenomenon comes from studies considering only one facilitator species. What happens when there are two facilitator species in the community? Are the facilitation effects by one species being altered by the presence of a potentially second facilitator species and vice‐versa (i.e. bidirectional facilitation)?Knowing that cushion plants ameliorate stress and improve soil fertility and that cluster root‐bearing species mobilize soil phosphorus (P), we investigated the potential occurrence of bidirectional facilitation via stress amelioration and nutrient exchange in the cushion plant Acaena integerrima (Rosaceae) and the cluster root‐bearing tree species Embothrium coccineum (Proteaceae).In southern Chile, where both species naturally occur, we compared aspects of the vegetative and reproductive performance of each species growing in association or not. We also determined if Embothrium alters the nurse effects of Acaena cushions on other species by evaluating species richness, frequency, and abundance in cushion plants with and without Embothrium. To infer the existence of nutrient exchange, we determined soil and leaf nutrient levels of both species.Species richness, frequency and abundance were higher within than outside Acaena cushions. Although the presence of Embothrium did not enhance the overall positive effects of Acaena on species composition, nine species occurred more frequently when Embothrium was present. Embothrium occurred more frequently and had a higher survival and leaf nitrogen (N) concentration when growing with Acaena than without it, although its growth and leaf P concentration were lower. In contrast, Acaena had a lower number of and mass of fruits per inflorescence and a higher leaf P concentration when growing with versus growing without Embothrium.Synthesis. The cushion plant Acaena integerrima facilitates the occurrence of many species in the community, including the cluster root‐bearing species Embothrium coccineum, which in turn enhances the facilitation effect of Acaena on certain species. When Embothrium and Acaena occur together, the latter improves its nutritional status but reduces its fitness, implying a lack of bidirectional facilitation. [ABSTRACT FROM AUTHOR]

Aim: Tree invasions are a threat to biodiversity conservation, and although it is hard to predict the future spread of invasive tree species, there are tools available which could allow some estimations. The magnitude of spatial spread (a proxy of invasiveness) can be predicted from species climatic requirement (climatic niche) and can be represented by species distribution models (SDMs). We aimed to assess whether Acacia dealbata conserves its niche in the new environment of south‐central Chile, and also, to estimate the invasive stage of the species. Location: South‐central area of Chile, between the O'Higgins (34°0″0′S) and Aysen Regions (47°0″0′S). Methods: We used a combination of global, native, and regional data to improve the estimation of the potential distribution of A. dealbata, which has been considered one of the most invasive species of the genus, being registered in at least 34 countries in all the Continents. Results: Our results show that A. dealbata does not conserve its niche in the study area, invading areas with climatic conditions different from those of the native range. It is also not at equilibrium with the environment. According to the global versus regional SDM comparisons, populations present in south‐central Chile present different invasion stages. There are some stable populations, but there are other populations colonizing new areas, occupying unsuitable habitats and some of them are adapting to new climatic conditions. Climatic factors, such as precipitation seasonality, could be acting behind the expansion to new environments, and biotic factors or dispersal limitations could be preventing the species to colonize suitable areas. Main conclusions: The invasion process of A. dealbata is far from stabilizing, and management options should focus on prevention, avoiding, for example, the introduction of the species to Patagonia where the species has not spread yet. More research is needed to complement our results and enhance the development of effective management strategies. [ABSTRACT FROM AUTHOR]

The sei whale (Balaenoptera borealis) is one of the least known whale species. Information on sei whale distributions and its regional variability in the south-eastern Pacific Ocean are even more scarce than that from other areas. Vocalizations of sei whales from this region are not described yet. This research presents the first characterization of sei whale sounds recorded in Chile during the austral autumn of 2016 and 2017. Recordings were done opportunistically. A total of 41 calls were identified to be sei whale downsweeps. In 2016, calls ranged from an average maximum frequency of 105.3 Hz down to an average minimum of 35.6 Hz over 1.6 s with a peak frequency of 65.4 Hz. During 2017, calls ranged from an average maximum frequency of 93.3 down to 42.2 Hz (over 1.6 s) with a peak frequency of 68.3 Hz. The absolute minimum frequency recorded was 30 Hz and the absolute maximum frequency was 129.4 Hz. Calls generally occurred in pairs, but triplets or singles were also registered. These low-frequency sounds share characteristics with recordings of sei whales near the Hawai'ian Islands but with differences in the maximum frequencies and duration. These calls distinctly differ from sounds previously described for sei whales in the Southern Ocean and are the first documented sei whale calls in the south-eastern Pacific. [ABSTRACT FROM AUTHOR]

Quaternary climatic oscillations have impacted Patagonian sigmodontine fauna, leaving traceable genetic footprints. In southern Chile, changes in the landscape included transitions to different vegetation formations as well as the extension of ice sheets. In this study, we focus on the Valdivian forest endemic and recently described sigmodontine species Abrothrix manni. We aim to assess the genetic structure of this species, testing for the existence of intraspecific lineages, and inferring the recent demographic history of the species. Analyses were based on the first 801 bp of the mitochondrial gene Cytocrhome-b from 49 individuals of A. manni collected at 10 localities that covers most part of its geographic distribution. Genealogical analyses recovered two main intraspecific lineages that are geographically segregated and present an intermediate site of secondary contact. Historical demography shows signal of recent population decrease. Based on these results, we proposed that current genetic diversity of A. manni differentiated in at least two distinct refugial areas in southern Chile. This scenario, in addition to be unique among those uncovered for the so far studied Valdivian forest rodents, is noteworthy because of the reduced geographic scale inhabited by the species. [ABSTRACT FROM AUTHOR]

In this work, we assessed the feasibility of using optical flow to obtain the motion estimation of a glacier. In general, former investigations used to detect glacier changes involve solutions that require repeated observations which are many times based on extensive field work. Taking into account glaciers are usually located in geographically complex and hard to access areas, deploying time-lapse imaging sensors, optical flow may provide an efficient solution at good spatial and temporal resolution to describe mass motion. Several studies in computer vision and image processing community have used this method to detect large displacements. Therefore, we carried out a test of the proposed Large Displacement Optical Flow method at the Viedma Glacier, located at South Patagonia Icefield, Argentina. We collected monoscopic terrestrial time-lapse imagery, acquired by a calibrated camera at every 24 hour from April 2014 until April 2015. A filter based on temporal correlation and RGB color discretization between the images was applied to minimize errors related to changes in lighting, shadows, clouds and snow. This selection allowed discarding images that do not follow a sequence of similarity. Our results show a flow field in the direction of the glacier movement with acceleration in the terminus. We analyzed the errors between image pairs, and the matching generally appears to be adequate, although some areas show random gross errors related to the presence of changes in lighting. The proposed technique allowed the determination of glacier motion during one year, providing accurate and reliable motion data for subsequent analysis. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article discusses a study on the effects of volcanic-related natural sedimentation on Trichoptera or caddisfly species found in Chubut province, Argentina. The researchers proposed that the mobility and swimming abilities of Trichoptera enabled their resistance to sediment deposition caused by the eruption of the Chaitén volcano. Species tolerance to sedimentation was found to be associated with traits such as respiration mode, filter-feeding habits, and rounded body shape.

Simple Summary: Two main challenges to control invasive mammals are to maximize campaign efficacy and cost-effectiveness, and to avoid trapping other species. We designed and tested new protocols to address those challenges to control alien American mink in southern Chile. We recommend the use of the GMV-13 variant of collapsible wire cage with scent gland lure, as they are smaller, cheaper, easier to transport and effective at catching female mink and reducing the possibility of trapping native species. Trapping campaigns using GMV-13 should be conducted principally during summer, with a 200-m trap spacing, for up to 6 days before moving traps to a new site, with a combination of three days with female scent gland lure followed by three days with male scent gland lure. Our modelling reveals that this should result in the removal of at least 70% of the local estimated discrete mink population within the area covered by each transect. Two main challenges when controlling alien American mink (Neovison vison) in Patagonia are to maximize campaign efficacy and cost-effectiveness and to avoid trapping native species. We designed and tested new variants of collapsible wire box traps, compared the efficacy of a food-based bait and a scent lure and compared catch rates in different seasons of the year. We used the data to model the efficiency rate of the trapping and to determine the trapping effort required to remove 70–90% of the estimated discrete mink population. Between January 2018 and March 2021, we operated 59 trapping transects over 103 three-day trapping periods in southern Chile. Traps were first baited with canned fish, and afterwards with mink anal gland lure. We compared the efficacy of mink capture with that of our previous study. We trapped 196 mink (125 males, 71 females), with most captures in summer. The medium-sized GMV-18 trap caught more male mink, but the more compact GMV-13 caught fewer non-target rodents and no native mammals. The scent lure was more successful than the canned fish when the previous campaign's data were included in the analysis. There was also a significant improvement in the proportion of female mink trapped and reduced labour compared with our previous campaign that used larger traps, fish bait and 400–500 m trap spacings. We caught relatively more females than males after the third night of trapping on a transect. Our data analysis supports the use of the GMV-13 variant of wire cage trap as the best trap size: it is effective on female mink, small, cheap and easy to transport. Combined with mink anal scent lure, it reduces the possibility of trapping native species compared with other traps tested in Chile. As the most efficient method for removing at least 70% of the estimated discrete mink population within the area covered by each trap transect in southern Chile tested to date, we recommend trapping campaigns using GMV-13 during summer, with a 200-m trap spacing, for up to 6 days before moving traps to a new site, with a combination of three days with a female scent gland lure, followed by three days with a male scent gland lure. [ABSTRACT FROM AUTHOR]

The study tests whether diurnal microhabitat use by Hatcheria macraei depends upon specific environmental parameters and/or the abundance of other fish. We carried out a 1-year field study in a low-order river of northern Patagonia, Pichileufu River, and used experimental trials to determine substrate preferences. Fishes were captured during daylight and physicochemical environmental variables were recorded. Headwater zones were dominated by rainbow trout ( Oncorhynchus mykiss) and brown trout ( Salmo trutta), while native fishes, H. macraei and the creole perch ( Percichthys trucha) were more abundant downstream. H. macraei inhabited mostly shallow microhabitats with fast water velocity and substrates having significant interstitial spaces, independently of the abundance of other fishes. Experimental trials pointed out that H. macraei preferred mostly coarser substrates (>6 cm), avoiding fine ones. This study highlights the importance of erosional zones with high water velocity, large substrates, and suitable interstitial space in the microhabitat selection of H. macraei. The knowledge of microhabitat use by native fish populations is critical for management and conservation strategies and should be taken into account before any river modification. [ABSTRACT FROM AUTHOR]

Competition arises when two co-occuring species share a limiting resource. Potential for competition is higher when species have coexisted for a short time, as it is the case for herbivores and livestock introduced in natural systems. Sheep, introduced in the late 19th century in Patagonia, bear a great resemblance in size and diet to the guanaco, the main native herbivore in Patagonia. In such circumstances, it could be expected that the two species compete and one of them could be displaced. We investigated spatial overlap and habitat selection by coexisting sheep and guanaco in winter and in summer. Additionally, we studied habitat selection of the guanaco in a control situation free from sheep, both in summer and winter. We also determined overlap between species in areas with different intensity of use (named preferred and marginal areas) in order to further detect the potential level of competition in the case of overlapping. Guanaco and sheep showed significantly different habitat preferences through all seasons, in spite of their spatial overlap at landscape scale. Additionally, the habitat used by guanaco was similar regardless of the presence or absence of livestock, which further indicates that sheep is not displacing guanaco where they coexist. These results suggest that habitat segregation between guanaco and sheep is due to a differential habitat selection and not to a competitive displacement process. Therefore, the potential for competition is considered low, contrary to what has been previously observed, although this could be a density-dependent result. [ABSTRACT FROM AUTHOR]

The shallow crustal Torres del Paine Intrusive Complex in southern Patagonia offers an opportunity to understand the chemical evolution and timing of crystallization processes in shallow plutonic rocks. It is characterized by hornblende-gabbros, gabbronorites, monzodiorites and granitic plutonic rocks. The exceptional exposure of the intrusion permits the identification of two structurally and petrographically different zones. Layered gabbronorite, olivine-bearing pyroxene–hornblende gabbronorite and monzodiorite forming vertical sheets and stocks in the west are referred to here as the feeder zone. These mafic rocks are in vertical contact with younger granitic rocks on their eastern border. The eastern part is a laccolith complex. It is characterized by three major units (I, II, III) of granitic rocks of over 1000 m vertical thickness; these are underlain in places by a sequence of hornblende-gabbro sills intermingled with evolved monzodiorite granite. Chilled, crenulated margins as well as flame structures between gabbroic rocks and monzodiorites suggest that the mafic sill complex remained partially molten during most of its construction. Bulk-rock major and trace element data indicate that the Paine mafic rocks follow a high-K calc-alkaline to shoshonitic differentiation trend. The parental magmas were basaltic trachyandesite liquids, with variable H2O and alkali contents. The majority of the feeder zone gabbronorites have high Al2O3 contents and positive Eu and Sr anomalies, consistent with accumulation of plagioclase and efficient extraction of intercumulus melt. The mafic sill complex largely lacks these cumulate signatures. Comparisons of the intercumulus groundmass in the hornblende-gabbros with intra-sill dioritic stocks and pods reveal similar rare earth element patterns and trace element ratios indicating incomplete extraction of evolved interstitial liquids. The Sr, Nd and Pb isotopic compositions of the mafic and granitic rocks exhibit ranges of 87Sr/86Sr of 0·704–0·708, ɛNd +3·8 to −1·2, 206Pb/204Pb 18·61–18·77, 207Pb/204Pb 15·67–15·67 and 208Pb/204Pb 38·56–38·77. Crystal fractionation and assimilation–fractional crystallization modelling, combined with high-precision U–Pb dating of zircons, indicates that the western feeder zone gabbronorites are linked to the uppermost Paine granite (granite I), whereas the mafic sill complex is younger and not directly related to the voluminous granite units II and III. These results are interpreted to indicate that crystal–liquid separation is facilitated in subvertical, dynamic feeder systems whereas subhorizontal sill complexes are inefficient in separating large volumes of mafic cumulates and complementary felsic rocks. [ABSTRACT FROM PUBLISHER]

Patagonia, located in southern South America, is a vast and remote region holding a rich variety of past environmental records but a small number of meteorological stations. Precipitation over this region is mostly produced by disturbances embedded in the westerly flow and is strongly modified by the austral Andes. Uplift on the windward side leads to hyperhumid conditions along the Pacific coast and the western slope of the Andes; in contrast, downslope subsidence dries the eastern plains leading to arid, highly evaporative conditions. The authors investigate the dependence of Patagonia's local climate (precipitation and near-surface air temperature) year-to-year variability on large-scale circulation anomalies using results from a 30-yr-long high-resolution numerical simulation. Variations of the low-level zonal wind account for a large fraction of the rainfall variability at synoptic and interannual time scales. Zonal wind also controls the amplitude of the air temperature annual cycle by changing the intensity of the seasonally varying temperature advection. The main modes of year-to-year variability of the zonal flow over southern South America are also investigated. Year round there is a dipole between mid- and high latitudes. The node separating wind anomalies of opposite sign migrates through the seasons, leading to a dipole over Patagonia during austral summer and a monopole during winter. Reanalysis data also suggests that westerly flow has mostly decreased over north-central Patagonia during the last four decades, causing a drying trend to the west of the Andes, but a modest increase is exhibited over the southern tip of the continent. [ABSTRACT FROM AUTHOR]

Copyright of Etnográfica: Revista do Centro de Estudos de Antropologia Social is the property of Centro em Rede de Investigacao em Antropologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

1. Altitudinal tree line ecotones (ATE) are among the most sensitive plant formations facing global warming as the altitudinal decrease in temperature is considered the driver controlling the upper elevation limit of tree lines world-wide. In this study, we attempted to answer the following questions: (i) how have the conditions during the last 2-3 centuries affected ATE tree growth (physiology) and recruitment (demography)? and (ii) how strong is synchrony between these two processes at the ATEs? 2. We used spatial sampling grids at different ATEs in two ecosystems on two subcontinents: Nothofagus pumilio in the Andes of Chilean Patagonia (46° SL) and Pinus albicaulis in the Rockies of Western Montana, USA (46° NL). Basal increment cores were extracted from trees to estimate the growth and recruitment date. An annual detrended basal area increment was estimated for each tree and was modelled against elevation and time. 3. Tree growth improved over multiple centuries at all tree lines. Recently ( c. 50 years), however, improvements are disappearing or reversing. The uppermost tree line trees showed moderate declines in Montana and incipient declines in Patagonia. The declines are most dramatic slightly below current tree line ( c. 200 m). Tree recruitment patterns showed that tree lines have been moving uphill in both regions until at least 40-70 years ago. These movements occurred primarily through abrupt pulses upward with infilling occurring concurrently (Patagonia) or at some time thereafter (Montana). 4. Synchrony between growth and recruitment occurred in the 18th and 19th centuries in both regions. This synchrony was negative in Patagonia and positive in Montana, with varying lag periods. During the 20th century, these patterns of synchrony were lost at all sites. This loss of synchrony suggests that we could be entering a global period in which temperature is no longer the dominant driver of key features of tree lines. 5. Synthesis. Our study shows that at two structurally different tree lines, recent and initial declines in growth and losses of long-term synchrony are occurring in the latter part of the 20th century. These findings are opposite to simplistic expectations of global warming effects on tree line dynamics and call for a model reformulation that uncouples drivers of growth and recruitment. [ABSTRACT FROM AUTHOR]

Ombrotrophic bogs in southern Patagonia have been examined with regard to paleoclimatic and geochemical research questions but knowledge about organic matter decomposition in these bogs is limited. Therefore, we examined peat humification with depth by Fourier Transformed Infrared (FTIR) measurements of solid peat, C/N ratio, and δ13C and δ 15N isotope measurements in three bog sites. Peat decomposition generally increased with depth but distinct small scale variation occurred, reflecting fluctuations in factors controlling decomposition. C/N ratios varied mostly between 40 and 120 and were significantly correlated (R² > 0.55, p < 0.01) with FTIR-derived humification indices. The degree of decomposition was lowest at a site presently dominated by Sphagnum mosses. The peat was most strongly decomposed at the driest site, where currently peat-forming vegetation produced less refractory organic material, possibly due to fertilizing effects of high sea spray deposition. Decomposition of peat was also advanced near ash layers, suggesting a stimulation of decomposition by ash deposition. Values of δ 13C were 26.5±2‰ in the peat and partly related to decomposition indices, while δ15N in the peat varied around zero and did not consistently relate to any decomposition index. Concentrations of DOM partly related to C/N ratios, partly to FTIR derived indices. They were not conclusively linked to the decomposition degree of the peat. DOM was enriched in 13C and in 15N relative to the solid phase probably due to multiple microbial modifications and recycling of N in these N-poor environments. In summary, the depth profiles of C/N ratios, δ 13C values, and FTIR spectra seemed to reflect changes in environmental conditions affecting decomposition, such as bog wetness, but were dominated by site specific factors, and are further influenced by ash deposition and possibly by sea spray input. [ABSTRACT FROM AUTHOR]

The conservation of data deficient species is often hampered by inaccurate species delimitation. The galaxiid fishes Aplochiton zebra and Aplochiton taeniatus are endemic to Patagonia (and for A. zebra the Falkland Islands), where they are threatened by invasive salmonids. Conservation of Aplochiton is complicated because species identification is hampered by the presence of resident as well as migratory ecotypes that may confound morphological discrimination. We used DNA barcoding (COI, cytochrome b) and a new developed set of microsatellite markers to investigate the relationships between A. zebra and A. taeniatus and to assess their distributions and relative abundances in Chilean Patagonia and the Falkland Islands. Results from both DNA markers were 100% congruent and revealed that phenotypic misidentification was widespread, size-dependent, and highly asymmetric. While all the genetically classified A. zebra were correctly identified as such, 74% of A. taeniatus were incorrectly identified as A. zebra, the former species being more widespread than previously thought. Our results reveal, for the first time, the presence in sympatry of both species, not only in Chilean Patagonia, but also in the Falkland Islands, where A. taeniatus had not been previously described. We also found evidence of asymmetric hybridisation between female A. taeniatus and male A. zebra in areas where invasive salmonids have become widespread. Given the potential consequences that species misidentification and hybridisation can have for the conservation of these endangered species, we advocate the use of molecular markers in order to reduce epistemic uncertainty. [ABSTRACT FROM AUTHOR]

Glaciers are frequently used as indicators of climate change. However, the link between past glacier fluctuations and climate variability is still highly debated. Here, we investigate the mid- to late-Holocene fluctuations of Gualas Glacier, one of the northernmost outlet glaciers of the Northern Patagonian Icefield, using a multi-proxy sedimentological and geochemical analysis of a 15m long fjord sediment core from Golfo Elefantes, Chile, and historical documents from early Spanish explorers. Our results show that the core can be sub-divided into three main lithological units that were deposited under very different hydrodynamic conditions. Between 5400 and 4180 cal yr BP and after 750 cal yr BP, sedimentation in Golfo Elefantes was characterized by the rapid deposition of fine silt, most likely transported by fluvio-glacial processes. By contrast, the sediment deposited between 4130 and 850 cal yr BP is composed of poorly sorted sand that is free of shells. This interval is particularly marked by high magnetic susceptibility values and Zr concentrations, and likely reflects a major advance of Gualas glacier towards Golfo Elefantes during the Neoglaciation. Several thin silt layers observed in the upper part of the core are interpreted as secondary fluctuations of Gualas glacier during the Little Ice Age, in agreement with historical and dendrochronological data. Our interpretation of the Golfo Elefantes glaciomarine sediment record in terms of fluctuations of Gualas glacier is in excellent agreement with the glacier chronology proposed for the Southern Patagonian Icefield, which is based on terrestrial (moraine) deposits. By comparing our results with independent proxy records of precipitation and sea surface temperature, we suggest that the fluctuations of Gualas glacier during the last 5400 yr were mainly driven by changes in precipitation in the North Patagonian Andes. [ABSTRACT FROM AUTHOR]

Fire history reconstructions are typically based on tree ages and tree-ring fire scars or on charcoal in sedimentary records from lakes or bogs, but rarely on both. In this study of fire history in western Patagonia (47-48 S) in southern South America (SSA) we compared three sedimentary charcoal records collected in bogs with tree-ring firescar data collected at 13 nearby sample sites. We examined the temporal and spatial correspondence between the two fire proxies and also compared them to published charcoal records from distant sites in SSA, and with published proxy reconstructions of regional climate variability and large-scale climate modes. Two of our three charcoal records record fire activity for the last 4 ka yr and one for the last 11 ka yr. For the last ca. 400 yr, charcoal accumulation peaks tend to coincide with high fire activity in the tree-ring fire scar records, but the charcoal records failed to detect some of the fire activity recorded by tree rings. Potentially, this discrepancy reflects low-severity fires that burn in herbaceous and other fine fuels without depositing charcoal in the sedimentary record. Periods of high fire activity tended to be synchronous across sample areas, across proxy types, and with proxy records of regional climatic variability as well as major climate drivers. Fire activity throughout the Holocene in western Patagonia has responded to regional climate variation affecting a broad region of southern South America that is teleconnected to both tropical- and high-latitude climate drivers-El Ni"no- Southern Oscillation and the Southern Annular Mode. An early Holocene peak in fire activity pre-dates any known human presence in our study area, and consequently implicates lightning as the ignition source. In contrast, the increased fire activity during the 20th century, which was concomitantly recorded by charcoal from all the sampled bogs and at all fire-scar sample sites, is attributed to human-set fires and is outside the range of variability characteristic of these ecosystems over many centuries and probably millennia. [ABSTRACT FROM AUTHOR]

Glaciar Jorge Montt (48200 S/73300 W), one of the main tidewater glaciers of the Southern Patagonian Icefield (SPI), has experienced the greatest terminal retreat observed in Patagonia during the past century, with a recession of 19.5 km between 1898 and 2011. This retreat has revealed trees laying subglacially until 2003. These trees were dated using radiocarbon, yielding burial ages between 460 and 250 cal yrs BP. The presence of old growth forest during those dates indicates that Glaciar Jorge Montt was upvalley of its present position before the commonly recognized Little Ice Age (LIA) period in Patagonia. The post-LIA retreat was most likely triggered by climatically induced changes during the 20th century; however, Glaciar Jorge Montt has responded more dramatically than its neighbours. The retreat of Jorge Montt opened a 19.5 km long fjord since 1898, which reaches depths in excess of 390 m. The bathymetry is well correlated with glacier retreat rates, suggesting that dynamic responses of the glacier are at least partially connected to near buoyancy conditions at the ice front, resulting in high calving fluxes, accelerating thinning rates and rapid ice velocities. [ABSTRACT FROM AUTHOR]

The article focuses on a research conducted in order to evaluate themorphological differentiation and the sexual dimorphism within and between populations of the Chilean magnificent beetle, Ceroglossus chilensis using geometric morphometric in geographic areas of the Baker River Basin, Chilean Patagonia. It discusses the degrees of phenotypic disturbances as the ability of an individual to overcome the effects of stress.

The persistence and long-term memories in daily maximum and minimum temperature series during the instrumental period in southern South America were analysed. Here, we found a markedly seasonal pattern both for short- and long-term memories that can lead to enhanced predictability on intraseasonal timescales. In addition, well-defined spatial patterns of these properties were found in the region. Throughout the entire region, the strongest dependence was observed in autumn and early winter. In the Patagonia region only, the temperatures exhibited more memory during the spring. In general, these elements indicate that nonlinear interactions exist between the annual cycles of temperature and its anomalies. Knowledge of the spatiotemporal behaviour of these long-term memories can be used in the building of stochastic models that only use persistence. It is possible to propose two objective forecast models based on linear interactions associated with persistence and one that allows for the use of information from nonlinear interactions that are manifested in the form of forerunners. [ABSTRACT FROM AUTHOR]

Background: Understanding the factors that generate and maintain biodiversity is a central goal in ecology. While positive species interactions (i.e., facilitation) have historically been underemphasized in ecological research, they are increasingly recognized as playing important roles in the evolution and maintenance of biodiversity. Dominant habitat-forming species (foundation species) buffer environmental conditions and can therefore facilitate myriad associated species. Theory predicts that facilitation will be the dominant community-structuring force under harsh environmental conditions, where organisms depend on shelter for survival and predation is diminished. Wind-swept, arid Patagonian rocky shores are one of the most desiccating intertidal rocky shores ever studied, providing an opportunity to test this theory and elucidate the context-dependency of facilitation. Methodology/Principal Findings: Surveys across 2100 km of southern Argentinean coastline and experimental manipulations both supported theoretical predictions, with 43 out of 46 species in the animal assemblage obligated to living within the matrices of mussels for protection from potentially lethal desiccation stress and predators having no detectable impact on diversity. Conclusions/Significance: These results provide the first experimental support of long-standing theoretical predictions and reveal that in extreme climates, maintenance of whole-community diversity can be maintained by positive interactions that ameliorate physical stress. These findings have important conservation implications and emphasize that preserving foundation species should be a priority in remediating the biodiversity consequences of global climate change. [ABSTRACT FROM AUTHOR]

Diplolepis, a genus from southern South America traditionally considered monotypic, has recently been shown from molecular data to include a few species that form a monophyletic group at the base of the MOG dade of Asclepiadoideae (Apocynaceae). The species transferred to Diplolepis include plants from temperate South America mostly described under the generic name "Cynanchum". Phylogenetic analyses of cpDNA trnT-trnF and rps16 sequences of 51 accessions of Asciepiadaceae using maximum parsimony and Bayesian inference methods show that all "Cynanchum" from southern Argentina and Chile (except C. atacamense), Tweedia australis and Diplolepis form a well-supported monophyletic group. Within this group, three clades are recognized: two morphologically homogeneous groups from South Andean forests and high elevation areas, and a more diverse group in flower and leaf morphology from southern South American desert and semidesert areas. The phylogenetic position of C. atacamense is equivocal but the species is transferred to Diplolepis based on morphological and biogeographical coherence. The morphological, geographical and environmental characteristics of the three recognized clades of Diplolepis are discussed and eight nomenclatural changes are proposed. [ABSTRACT FROM AUTHOR]

Changes experienced in temperature, precipitation, demography and land coverage are the main themes studied in northwestern Patagonia, Argentina, which includes part of Neuquén, Río Negro and Chubut provinces. The precipitation shows important interannual variability and decreases during the warm semester. The mean minimum temperature in January in Neuquén city increased with statistical significance. Forests and steppe are the more important ecosystems of the area and the native forests of Nothofagus sp. are located mainly in protected areas like National or Provincial Parks. Twenty-eight percent of the Andean-patagonic forests are in the Río Negro province, while Neuquén province has 9% and Chubut province has 26%. The censuses of 1991 and 2001 showed that Los Lagos, Lacar, Picún Leufú and Cushamen are the counties with increasing population. [ABSTRACT FROM AUTHOR]