Area Of Patagonia Research Articles

Gastrointestinal parasites of Wolffsohn's viscacha (Chinchillidae: Lagidium wolffsohni), an endemic rodent species from the wild Patagonia.

Parasites are ubiquitous in wildlife populations and have a profound impact on population dynamics. Interest in parasites of wildlife has increased significantly in recent years, particularly in those with relevant conservation status. Patagonia is one of the wildest and remote areas of the world. The Wolffsohn's viscacha lives in a small mountainous area of Patagonia. Until now, little is known about the biology and ecology of this species. The aim of this research was to study the gastrointestinal parasite diversity in this rodent from a coprological survey. A total of 125 fecal samples from 25 colonies were examined. Each sample was rehydrated, homogenized, and analyzed using three parasitological techniques: spontaneous sedimentation, Mini-FLOTAC, and centrifugation-flotation in sucrose-saturated solution, followed by examination under optical microscopy. The samples, eggs, and oocysts of parasites were described, measured, and photographed. All colonies were positive for at least one parasite species. A total of 10 parasitic species were identified: Viscachataenia sp., possibly V. quadrata, Monoecocestus sp., an unidentified anoplocephalid, Heteroxynema sp., possibly H. (Cavioxyura) viscaciae, Helminthoxys sp., possibly H. effilatus, an unidentified strongylid-type egg, Trichuris sp., two morphologies of unidentified coccidians and Eimeria sp. This is the first exhaustive study of gastrointestinal parasites in L. wolffsohni and a large number of eggs and oocysts of parasites were found. Our results highlight the use of noninvasive techniques for the study of parasites of wildlife hosts; as in the case of this rodent with a remote habitat, which makes sampling difficult. The results of our study provide baseline information on gastrointestinal parasite infections in this species.

Evolutionary stages of active to vegetated coastal transgressive dunefields in the San Matías Gulf coast, Argentina

The understanding of how active aeolian coastal dunes transform into fully vegetated forms, and the specific dune configurations that emerge, particularly within coastal dune systems, is limited. This study examines the changes in dune morphology associated with vegetation growth within transgressive dunefields in NE Patagonia, Argentina. The dunefields are located along the northern coast of the San Matías Gulf, ranging from relatively small to large, and dominantly active in the past ∼80 years. Satellite and aerial images were analyzed using GIS procedures to calculate vegetation cover changes and dune migration rates and identify different dune types and their evolutionary stages of fixation. Five stages were defined in relation to vegetation cover and dune shapes and patterns, from bare sand to fully vegetated dunes. Transverse or barchanoid ridges (sometimes with aklé [fish scale], or chaotic patterns) convert to partially vegetated sub-parabolic dunes and finish as parabolic dunes. In other cases, the dunes may convert to reticulate, aklé, or chaotic patterns, completely vegetated. Various stages span a continuous range from unvegetated to fully vegetated dunes across a wide array of timeframes. In some cases, it was possible to recognize changes from stage one to five in ∼20 years. Where the initial transverse dune is largely maintained during the stabilization process a distinctive pattern named “gusanos” (worms) was identified. The vegetated surface measured in some areas changed from 11 % to 51 % vegetation cover between 1961 and 2022, with migration rates decreasing from 9.53 m/year to zero between 1991 and 2020. The increase in vegetation growth also coincides with higher temperatures, weaker winds and decreasing grazing livestock within this Patagonia area. The recorded processes are similar to coastal dune and vegetation changes in some semiarid regions from the Southern Hemisphere between 30 and 60° S, especially in South Australia.

One more word on Patagonian Ulota macrodontia: Ulota brachypoda sp. nov. (Orthotrichaceae, Bryophyta)

Abstract The bryophyte genus Ulota has its main diversification area in Patagonia, with 18 currently accepted species, all of which are endemic to the area. Despite this richness, ongoing studies indicate the existence of hitherto unknown species in this territory. However, the strong resemblance between species often complicates the discrimination of new taxa, making the use of integrative taxonomy approaches compulsory. During surveys conducted in past decades, a morphotype of a Ulota, closely resembling Ulota macrodontia, was discovered coexisting with this species. Ulota macrodontia is characterized by unique peristomial features within the genus, and the variant morphotype shares these characteristics while displaying some distinct gametophytic and sporophytic features. Biometric analyses demonstrate that the differences are stable, and without intermediate states. The results obtained from the analyses of one nuclear and four plastid loci reveal a close relationship between both morphotypes, with the samples of U. macrodontia forming a well-supported monophyletic group. We propose to treat the new morphotype at species level (Ulota brachypoda sp. nov.), discussing why this is the most appropriate taxonomic rank, and we provide a detailed and illustrated description. Additionally, a distribution map of the two endemics is included.

Shrub encroachment occurs near previously invaded areas in Patagonia (southern South America)

AbstractDuring the last century shrub encroachment has occurred in many arid and semiarid areas of the world. Patagonia is a large xeric territory located in the southern tip of South America, which has been grazed by sheep for more than a century. In many areas overgrazing led to vegetation change (shrub encroachment), which in turn reduced sheep carrying capacity and caused ranch abandonment. However, these changes in physiognomy did not occur everywhere, and even some authors did not find evidence that shrub encroachment is currently occurring. Our objectives were to determine if encroachment really happened in NE Patagonia and, in the case of confirming shrub encroachment, to evaluate if the increase in shrub density was spatially homogeneous. We used object‐based image analysis to evaluate shrub density and cover in aerial photographs taken in 1970 and 2018. In both dates, shrub density showed a clear contrast between two kinds of areas showing higher and lower density than was expected by chance. Shrub density and cover more than doubled between 1970 and 2018. This increase was concentrated in those areas with moderate or high densities of shrubs in 1970. Our results confirm the occurrence of shrub encroachment in NE Patagonia and demonstrate that it is currently concentrated near previously invaded areas. These findings have implications when defining protocols for monitoring shrub encroachment since monitors should focus on both areas that already have shrubs and areas that lack them.

Between conservation and care: Ontological mixtures and juxtapositions in protected areas of Patagonia, Argentina

AbstractBased on the discussion of the declaration of the Lanín volcano as a Mapuche sacred natural site, this article rethinks the relationship between conservation and care from an ethnographic perspective, paying special attention to the relationship between the entities volcano and pijan mawiza. The exploration occurs within the framework of the intercultural proposal behind the co‐management of the National Parks in Argentina. I argue that the “multiculturalist” perspective based on interculturality and “dialogues of knowledge” has turned conservation and care into interchangeable synonyms, but that this translation renders invisible the possibility of addressing—from an ontological perspective—other worlds struggling to exist. The article reflects on the potentials of care to pluralize conservation based on juxtapositions of, and mixtures with, other forms of making world(s).

Settling environmental citizenship: The presentation of self in conservation encounters

AbstractFar from a settled fact, environmental citizenship is always in the making. In this article, we analyze how the settlers of a protected area in Patagonia, Argentina, seek to legitimize their claims for natural resources and territory through strategic representations of themselves. The self‐presentation molds not only their own political subjects, but also the public authority of the governing offices. We argue that the legitimization of public institutions is partial and fragmented, allowing settlers to legitimize their claims and become active producers of environmental citizenship. The conservation encounters reproduce social practices, cultural symbols, and governmental artifacts. In this way, they contribute to the affirmation of state authority and the hegemony of the nation‐state through their reproduction of the Patagonian imaginaries, while also curbing the sphere of influence of any particular institution.

Common juniper, an overlooked conifer with high invasion potential in protected areas of Patagonia

The benefits of early detection of biological invasions are widely recognized, especially for protected areas (PAs). However, research on incipient invasive plant species is scarce compared to species with a recognized history of invasion. Here, we characterized the invasion status of the non-native conifer Juniperus communis in PAs and interface areas of Andean Patagonia, Argentina. We mapped its distribution and described both the invasion and the environments this species inhabits through field studies, a literature review, and a citizen science initiative. We also modeled the species’ potential distribution by comparing the climatic characteristics of its native range with those of the introduced ranges studied. The results show that J. communis is now widely distributed in the region, occurring naturally in diverse habitats, and frequently within and close to PAs. This species can be considered an incipient invader with a high potential for expansion in its regional distribution range, largely due to its high reproductive potential and the high habitat suitability of this environment. Early detection of a plant invasion affords a valuable opportunity to inform citizens of the potential risks to high conservation value ecosystems before the invader is perceived as a natural component of the landscape.

Potential effects of climate change on the growth response of the toxic dinoflagellate Karenia selliformis from Patagonian waters of Chile

Northern Patagonia (41–44°S) is affected by climatic, hydrological and oceanographic anomalies, which in synergy with processes such as global warming and acidification of the coastal oceans may affect the frequency and intensity of harmful algal blooms (HABs). Greater frequency of HABs has been reported in the southeastern Pacific Ocean, including blooms of the toxic dinoflagellate Karenia selliformis, causing massive mortality of marine fauna in the oceanic and coastal areas of Patagonia. The objective of this study was to determine the effects of temperature and pH interaction on the growth of K. selliformis (strain CREAN_KS02), since these factors have wide seasonal fluctuations in the Patagonian fjord ecosystem. The CREAN_KS02 strain isolated from the Aysén Region (43°S) was used in a factorial experiment with five pH levels (7.0, 7.4, 7.7, 8.1 and 9.0) and two temperatures (12 and 17 °C) during a period of 18–21 days. Results indicated a significant effect of temperature and pH interaction on growth rate (range 0.22 ± 0.00 to 0.08 ± 0.01 d−1) and maximum density (range 13,710 ± 2,616 to 2,385 ± 809 cells mL−1) of K. selliformis. The highest density and growth of K. selliformis was found at 12 °C with a reduced pH (7.0–7.7). The results suggest that the current environmental conditions of coastal Patagonia, waters of low temperature and relatively low pH, may be favorable for the development of blooms of this species during autumn. We suggest that there is natural plasticity of K. selliformis in a wide pH range (7.0–8.1) but in a narrow low temperature range (10.6–12.9 °C), values that are typically recorded in the oceanic region of northern Patagonia. In contrast, in an extreme climate change scenario (ocean warming and coastal acidification) in northern Patagonia, a negative effect on the growth of K. selliformis may be expected due to amplification of the acidification effects caused by the thermal stress of high temperature water.

Dispersion of arsenic species from highly explosive historical volcanic eruptions in Patagonia

Andean volcanic rocks typically have low to moderate arsenic (As) concentrations. However, elevated levels of As in groundwaters of southern South America have been reported as a consequence of weathering of volcanic glass. This study discusses the abundance, speciation and dispersion of As species in fresh volcanic ash from highly explosive (Volcanic Explosivity Index: 4–5) Patagonian eruptions, as well as the potential of As release to aqueous reservoirs. Synchrotron-based X-ray absorption and micro-focused X-ray photoelectron spectroscopies were used to evaluate As solid speciation. Batch experiments at different pH conditions were performed with the aim of understanding the controls on As release to aqueous reservoirs. Bulk chemical and mineralogical characterizations were performed by inductively coupled plasma optical emission spectroscopy, X-ray diffraction and scanning electron microscopy/energy dispersive spectroscopy. Finally, to understand how As-bearing phases are spatially distributed after eruptions, simulations of volcanic ash emission, transport and deposition were performed.Results indicate that the concentration, speciation, and mobility of As in fresh Patagonian volcanic ash depend on the silica content of source magmas. Although the main As host in volcanic ash is Al-silicate glass, this phase is stable at neutral pH characteristic of most aqueous reservoirs. Higher contributions of As to water are associated with the more mobile As species that concentrate onto the surface of Al-silicate glass. Atmospheric dispersion simulations revealed that primary fallout of As-bearing ash has affected large areas in Patagonia, but also reached the Chaco-Pampean plain, where the presence of As-rich groundwater has been widely documented.

Trends in ANPP Response to Temperature in Wetland Meadows across a Subcontinental Gradient in Patagonia

Due to ongoing global warming, seasonal patterns of aboveground net primary production (ANPP) may be altered by temperature trends. Of particular interest is the seasonal association between ANPP and temperature at the beginning of the growing season (the period encompassing minimum to maximum ANPP), where two contrasting mechanisms are in tension. On the one hand, the restrictions exerted by low temperatures in winter may be relaxed, increasing the slope of seasonal association between ANPP and temperature over the years. On the other hand, increases in temperature may increase water demand, reducing the slope over time. Across 543 wetland meadow areas in Patagonia, we estimated ANPP and obtained temperature records on a monthly basis from 2001 to 2019. The seasonal association between ANPP and temperature, tested through linear regression, was statistically significant in 96% of the cases (9921/10317 (543 wetland areas × 19 growing seasons)). The fitted linear models explained, on average, 84% of ANPP seasonal (June–December) variations. Through regression trees, we found out that the two tested mechanisms, the relaxation of temperature restriction and the increase in water demand, showed clear spatial patterns. The relaxation due to temperature increase took place at higher latitudes, but the water-limiting mechanism increased over mid-latitude areas.

Krill diel vertical migration in Southern Patagonia

AbstractDiel vertical migration (DVM) of krill was studied throughout 36 h at a fixed station (46.05°S, 66.19°W; 98-m depth) located in the center of the San Jorge Gulf, Southern Patagonia area, during February 2014. Using an echosounder system, combined with an autonomous Video Plankton Recorder (Auto-VPR) and Jacknet samplings, we describe the migration pattern, the associated biomass and the macrozooplankton species involved. The net sampling and the Auto-VPR images allowed us to identify the krill species detected in the echosounder signals, which corresponded to Euphausia lucens, Euphausia vallentini and Nematoscelis megalops. The krill community followed a “normal pattern” of DVM, ascending at dusk (~18:30 h) and descending at dawn (~06:30 h), forming a dense layer near the bottom during the day. Krill vertical migration speed was estimated from the echogram data at ~ 1 cm s−1 (1 body length per s for 1-cm-long animal), and the integrated mean biomass was 57.8 g m−2. This study provides a description of temporal and spatial patterns of krill vertical distribution, which should be taken into account when studying the complexity of the SJG ecosystem dynamics and carbon flux.

Interaction between Vespula germanica and Apis mellifera in Patagonia Argentina apiaries

Social wasps are important predators of honeybees, attacking hives to steal honey, pollen, larvae, and adults. Wasps of the genus Vespula are considered agricultural pests in many invaded areas, but their impact on Apis mellifera in these areas is poorly understood. Here, we studied agonistic interactions between V. germanica wasps and honeybees in Patagonia, Argentina. We found that the attack intensity was positively correlated with wasp density and that the colonies with lower honeybee traffic were the most affected by the wasps. We conclude that V. germanica has a significant impact on honeybees in this invaded area in Patagonia suggesting beekeepers need to be alert during the summer months to reduce wasp density of this insect pest.

Discriminating the biophysical signal from human-induced effects on long-term primary production dynamics. The case of Patagonia.

The temporal trend of aboveground net primary production (ANPP) is frequently used to estimate the effect of humans on ecosystems. In water-limited ecosystems, like most grazing areas in the world, the effect of humans act upon ANPP in combination with environmental variations. Our main objective was to quantify long-term (1981-2012) changes of ANPP and discriminate the causes of these changes between environmental and human at a subcontinental scale, across vast areas of Patagonia. We estimated ANPP through a radiative model based on remote sensing data. Then, we evaluated the relation between ANPP and environmental interannual variations of two hierarchically related factors: El Niño Southern Oscillation (ENSO) through the Southern Oscillation Index (SOI), and precipitation. We described the effect of humans through the shape of the temporal trends of the residuals (RESTREND) of the environmental model and quantified human relative impact through the RESTREND: ANPP trend ratio. ANPP interannual variation was significantly explained by ENSO (through SOI) and precipitation in 65% of the study area. The SOI had a positive association with annual precipitation. The association between ANPP and annual precipitation was positive. RESTREND analysis was statistically significant in 92% of the area where the tested environmental model worked, representing 60% of the study area, and it was mostly negative. However, its magnitude, revealed through the RESTREND: ANPP trend ratio, was relatively mild. Our analysis revealed that most of ANPP trends were associated with climate and that even when human density is low, its incidence seems to be mainly negative.

Discovering the Role of Patagonian Birds in the Dispersal of Truffles and Other Mycorrhizal Fungi

Dispersal is a key process that impacts population dynamics and structures biotic communities. Dispersal limitation influences the assembly of plant and microbial communities, including mycorrhizal fungi and their plant hosts. Mycorrhizal fungi play key ecological roles in forests by feeding nutrients to plants in exchange for sugars, so the dispersal of mycorrhizal fungi spores actively shapes plant communities. Although many fungi rely on wind for spore dispersal, long-distance dispersal is uncommon and most spores land close to fungal fruiting bodies. Some fungi have lost the ability to shoot their spores into the air and instead produce enclosed belowground fruiting bodies (truffles) that rely on animals for dispersal. Animal-facilitated spore dispersal increases the chances that spores reach suitable habitats and colonize plant roots. The role of mammals in fungal spore dispersal is well documented but the relevance of birds as dispersal agents of fungal spores has been understudied, despite the prominence of birds as seed dispersal vectors. Here we use metagenomics and epifluorescence microscopy to demonstrate that two common, widespread and endemic birds from Patagonia, Chucao Tapaculos (Scelorchilus rubecula) and Black-throated Huet-huets (Pteroptochos tarnii), regularly consume mycorrhizal fungi and disperse viable spores via mycophagy. We sampled more than 100 fecal samples that were collected across a 700 kilometer area in Patagonia. Our metagenomic analysis indicates that these two species of generalist, ground-dwelling birds routinely consume diverse mycorrhizal fungi, including many truffles, that are symbiotically associated with Nothofagaceae trees that dominate Patagonian forests. We used soil sample controls to ensure that fecal samples were not contaminated from nearby soil as well as extraction, PCR and sequencing controls to account for lab contamination. Epifluorescence microscopy of fecal samples confirmed that the birds dispersed large numbers of viable spores from truffles and other mycorrhizal fungi, including Cystangium nothofagi and species of Cortinarius, Descolea, and Inocybe, which are important root colonizers of seedling and saplings of several Nothofagaceae species. Our results show that fungi are a common food for both bird species and that this cryptic animal-fungi symbiosis is widespread and ecologically important in Patagonia. Our findings suggest that birds may also act as cryptic but critical agents of fungal spore dispersal in other ecosystems.

Revised chrono and lithostratigraphy for the Oligocene-Miocene Patagoniense marine deposits in Patagonia: Implications for stratigraphic cycles, paleogeography, and major drivers

Richly fossiliferous upper Oligocene to lower Miocene Patagoniense marine deposits constitute a conspicuous feature of the sedimentary record of most basins in Patagonia. Patagoniense meaning and subdivisions have been confusing, and correlation and elucidation of factors controlling sedimentation in a region as extensive as Patagonia are still highly debated. Our revision of the distribution, correlation, stratigraphic arrangement, and timing of deposition, allows redefining the Patagoniense as a succession of widely distributed marine sediments accumulated in Patagonia from ~25 to 15 Ma, showing different timing of accumulation for each basin. It can also be conceived as a higher rank stratigraphic cycle of relative sea-level fluctuation, which comprises two medium rank stratigraphic cycles spanning 2–4 Myr each, in turn enclosing several lower rank cycles of less than 1 Myr. The late Oligocene (~25-23 Ma) medium rank cycle shows deposits restricted mostly to the coastal area of Tierra del Fuego and Santa Cruz provinces in the Austral-Magallanes Basin, which respond to a combination of global sea-level fluctuations and flexural subsidence. The overlying early Miocene (~22-15 Ma) medium rank cycle comprises sediments deposited over extensive areas of Patagonia with a maximum flooding at 20-19 Ma suggesting, in addition to tectonic subsidence in the Austral-Magallanes Basin, regional long-wavelength subsidence and a global sea level component for this episode. The timing and thickness of the regressive part of this cycle show differences for each basin, suggesting the action of local sedimentary controls such as differential rates of sediment supply. Further geochronological and stratigraphic studies are necessary, especially for the northern exposures, which will allow improving time-constrained paleogeographic reconstructions.

Two complex typifications and a new name to unravel Ulota germana sensu Malta non (Mont.) Mitt. (Orthotrichaceae)

Ulota germana is an epiphytic moss moderately common in oceanic areas of Patagonia (southern South America), one of the regions of the world where Ulota reaches a peak of diversity. It is easily recognized by very long perichaetial leaves, which reach the capsule when wet, an endostome of eight segments and verrucose spores. In Nikolajs Malta's revision of South American Ulota, a species was described under this name with apparently similar long perichaetial leaves and spores but with a 16-segment endostome, an uncommon character in this genus. No further references to this particular combination of traits are found throughout the literature of South American Ulota. In the same work, Malta also published U. germana var. breviseta. During the study of recent Patagonian collections, a moss similar to that described by Malta was repeatedly found, living together with U. germana s.str. To ascertain the name and taxonomic identity of the new specimens and Malta's moss, a detailed morphological comparative study was carried out. Original material of relevant names was analyzed, demonstrating that the gatherings on which those names are based were usually a mixture of several species, thus resulting in nomenclatural confusion. Having established that the plants described by Malta at both specific and varietal ranks are not U. germana, we formally describe them as U. maltiana with a complete description and illustration. Ulota germana s.str. is also illustrated for comparison. The reasons behind Malta's error are discussed. We demonstrate that the previous typification of U. germana was incorrect, and propose a new lectotypification for this species and for U. germana var. breviseta.

Parasite community of Patagonotothen cornucola (Pisces: Nototheniidae) from intertidal rocky pools from Strait of Magellan

Notothens are abundant fish in the Austral Ocean, therefore they stablish many interactions with other species, and thus they have become important components in the ecosystem. However, the relationships between these fish and their parasites are poorly understood. The parasite community of the intertidal notothen Patagonotothen cornucola has been analyzed in this study considering two sampling sites at the Strait of Magellan and the sex of the fish. The fish samples were collected in January 2017 at Rinconada Bulnes (RB), and San Isidro (SI). A total of 98 fish individuals, with total body length between 4.2 and 13.4 cm, were obtained. Of these fish, 15 parasite species were recorded. Four species were the most prevalent or abundant, three digeneans (Caudotestis kerguelensis, Whitegonimus ozoufae and Genolinea cf. bowersi) and one acantocephalan (Corynosoma beaglense). The similarity of parasite composition based on the abundance of parasites showed significant differences among sites because the fish from SI had only five parasite species and two of them with higher abundances than RB. There were no differences in parasite composition between male and female fish. Therefore, the sampling site was important for composition and abundance of parasites, indicating ecological and environmental differences between sites that affect parasite transmission. This is the first study on the parasite community of a species of Patagonotothen in the Patagonia area, showing a wide diversity of parasite species in this little fish.

Mercury in a geothermal and volcanic area in Patagonia, southern South America

Mercury and heavy metal contents are monitored using lichens as a tool for evaluation of air pollution. Lichens allow the identification of zones with anthropic impact, pollution hotspots and natural sources of contamination like volcanic emissions. The concentration of mercury (Hg) semivolatiles and rare-earth elements (REEs) were measured in our case in fruticose lichen thalli and soils collected in an active volcanic area: the Copahue-Caviahue Volcanic Complex, in northern Patagonia, South America. The present research focus on Hg-release patterns and its association to elements such as sulphur (S) and bromine (Br). In order to discriminate the particulate from the gaseous forms the concentration ratios of elements to magnesium (Mg) were computed. The Hg vs. Br concentration linear regression, together with the Hg normalised concentration vs. volcano distance, suggest that Hg from volcanic origin may be oxidised changing to reactive forms in the ash plume. Total mercury concentration in fruticose lichens (0.207–0.331 μg g−1) in Copahue-Caviahue volcanic area were higher than those from several other volcanic areas in South America, USA and Italy (0.010–0.290 μg g-1). Nevertheless, the consequent deposition has not generated a net contamination in soils.

Paleodietas en restos humanos del bosque meridional de Neuquén, Patagonia Argentina

Three novel records of carbon and nitrogen isotopes are presented from two open-air funerary contexts in the interior of the North Patagonian forest. The human samples analyzed confirm the usefulness of the technique to differentiate terrestrial diets from human populations in the Andean area of Patagonia. The results reflect the importance of the forest and its resources in the last millennium, strengthening the models suggesting human populations regularly and permanently exploiting the forest and its resources in the eastern Andean region of northern Patagonia.

Characterization of Non-Angora (´Creole Hairy´) Goat´s Fiber from the Northern Patagonia Area of Argentina. Potential Textile use as Patagonian Cashmere/h2>

Characterization of Non-Angora (´Creole Hairy´) Goat´s Fiber from the Northern Patagonia Area of Argentina. Potential Textile use as Patagonian Cashmere/h2>