Geochemistry and Sr-Nd-Pb isotopic constraints on the petrogenesis of Cenozoic lavas from the Pali Aike and Morro Chico area (52°S), southern Patagonia, South America

Island Arc ◽  
2012 ◽  
Vol 21 (4) ◽  
pp. 327-350 ◽  
Author(s):  
Mi Kyung Choo ◽  
Mi Jung Lee ◽  
Jong Ik Lee ◽  
Kyu Han Kim ◽  
Kye-Hun Park
Keyword(s):  
South America ◽  
Southern Patagonia ◽  
Isotopic Constraints

Salicornia cuscoensis (Amaranthaceae/Chenopodiaceae), a new species from Peru (South America)

Phytotaxa ◽  
2017 ◽  
Vol 319 (3) ◽  
pp. 254 ◽  
Author(s):  
M. ÁNGELES ALONSO ◽  
MANUEL B. CRESPO ◽  
HELMUT FREITAG
Keyword(s):  
New Species ◽  
South America ◽  
Morphological Characters ◽  
Tierra Del Fuego ◽  
South American ◽  
Habitat Distribution ◽  
Closely Related Species ◽  
Molecular Analyses ◽  
Southern Patagonia ◽  
A New Species

The name Salicornia cuscoensis given to a plant from high Andean saltmarshes near Cusco [Cuzco] and Ayacucho, Peru (South America) is validated by a diagnosis and description. The main morphological characters that separate S. cuscoensis from other closely related species are creeping habit, delicate branches, inflorescence of short and thin spikes, and seed indumentum. The new species clearly differs from other perennial Salicornia taxa growing in high Andean saltmarshes such as S. pulvinata and S. andina. The former forms small compact cushions producing very short, few-flowered inflorescences. The latter shows woody stems and forms larger rounded carpets. Morphologically, S. cuscoensis is also similar to S. magellanica, a species growing along the seashore in southern Patagonia and Tierra del Fuego, but the latter has shorter and wider inflorescences and larger seeds with a different type and arrangement of indumentum. Molecular analyses also supported the separation of S. cuscoensis. Data on habitat, distribution and phylogenetic relationships are presented for the new species and its relatives, and an identification key is given for the South American taxa of the genus Salicornia.

scholarly journals The South-American distribution and southernmost record of Biomphalaria peregrina—a potential intermediate host of schistosomiasis

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3401 ◽  
Author(s):  
Alejandra Rumi ◽  
Roberto Eugenio Vogler ◽  
Ariel Aníbal Beltramino
Keyword(s):  
16S Rrna ◽  
South America ◽  
Potential Distribution ◽  
Phylogenetic Analyses ◽  
Distribution Model ◽  
South American ◽  
Intermediate Hosts ◽  
Morphological Examination ◽  
Widespread Species ◽  
Southern Patagonia

Schistosomiasis remains a major parasitic disease, endemic in large parts of South America. Five neotropical species of Biomphalaria have been found to act as intermediate hosts of Schistosoma mansoni in natural populations, while others have been shown to be susceptible in experimental infections, although not found infected in the field. Among these potential intermediate hosts, Biomphalaria peregrina represents the most widespread species in South America, with confirmed occurrence records from Venezuela to northern Patagonia. In this study, we report the southernmost record for the species at the Pinturas River, in southern Patagonia, which finding implies a southward reassessment of the limit for the known species of this genus. The identities of the individuals from this population were confirmed through morphological examination, and by means of two mitochondrial genes, cytochrome oxidase subunit I (COI) and 16S-rRNA. With both markers, phylogenetic analyses were conducted in order to compare the genetic background of individuals from the Pinturas River with previously genetically characterized strains of B. peregrina from various South-American locations. In addition, we produced a potential distribution model of B. peregrina in South America and identified the environmental variables that best predict that distribution. The model was estimated through a maximum entropy algorithm and run with occurrence points obtained from several sources, including the scientific literature and international databases, along with climatic and hydrographic variables. Different phylogenetic analyses with either the COI or 16S-rRNA sequences did not conflict, but rather gave very similar topological organizations. Two major groups were identified, with sequences from the Pinturas River grouping together with haplotypes from subtropical and temperate regions. The model developed had a satisfactory performance for the study area. We observed that the areas with higher habitat suitability were found to be mainly linked to subtropical and temperate regions of South America between 15° and 45° south latitude, with different moderate- and low-suitability areas outside this range. We also identified the coldest temperatures as the main predictors of the potential distribution of this snail. Susceptibility surveys would be required to evaluate if southern populations of B. peregrina still retain their potential as intermediate hosts of S. mansoni.

Migration Routes and Stopover Sites of Upland Geese Chloephaga Picta in South America

2018 ◽  
Vol 11 (2) ◽  
pp. 89-99 ◽  
Author(s):  
Julieta Pedrana ◽  
Klemens Pütz ◽  
Lucía Bernad ◽  
Juan Pablo Seco Pon ◽  
Antonella Gorosabel ◽  
...  
Keyword(s):  
South America ◽  
Large Scale ◽  
Buenos Aires Province ◽  
Migration Routes ◽  
Stopover Sites ◽  
Precise Knowledge ◽  
Southern Patagonia ◽  
Breeding Grounds ◽  
Migratory Routes ◽  
Upland Goose

The Upland Goose (Chloephaga picta picta) is a migratory species of South America, which breeds from September to April in Patagonia (Argentina and Chile) and winters from May to September in the southern Pampas (Argentina). Despite some protection in both countries, this species is still persecuted and large numbers are killed by unregulated hunting. Therefore, precise knowledge of their migratory routes is vital to ensure protection of necessary resources and sites throughout the year. We deployed five miniaturised satellite transmitters on adult Upland Geese to gather data about breeding, wintering and stopover sites all along their migratory routes. We aimed to identify important areas in the wintering and breeding grounds through kernel density analyses, and to match these sites along the migration routes with protected areas. Tracked birds exhibited different migration routes and reached different breeding grounds. Two individuals travelled from their wintering grounds in Buenos Aires province to their presumed breeding areas in southern Patagonia. However, we also found different stopover sites from another bird in northern Patagonia, from the ones postulated before, and evidence that some Upland Geese are not large-scale migrants. Our results highlight a considerable amount of plasticity in Upland Geese migratory behaviour. This study represents an essential first step towards identifying important stopover sites along the Upland Geese flyways and it also highlights the lack of protected habitats along most of their migration routes.

scholarly journals Effects of weather events on X-SAR returns from ice fields: case-study of Hielo Patagónico Sur, South America

1997 ◽  
Vol 24 ◽  
pp. 367-374 ◽  
Author(s):  
Richard R. Forster ◽  
Laurence C. Smith ◽  
Bryan L. Isacks
Keyword(s):  
South America ◽  
Space Shuttle ◽  
Temperature Drop ◽  
Precipitation Event ◽  
Glacier Surface ◽  
Abrupt Decrease ◽  
Near Surface ◽  
Surface Conditions ◽  
Southern Patagonia ◽  
Wet Snow

The space-shuttle-based SIR-C/X-SAR synthetic aperture radar (SAR) imaged part of Hielo Patagónico Sur (HPS; southern Patagonia ice field, South America) for five successive days during missions in April and October 1994. A significant meteorological event occurred during each mission, including a major storm in April and a sharp temperature decrease in October. Changes in backscatter are observed for both episodes in X-SAR returns from the mid-portions of one of the two large outlet glaciers in the study area. Ground-station and satellite meteorological, and hydrological data are combined with the daily X-SAR images to interpret changes in glacier surface conditions caused by meteorological events. Effects interpreted from the April storm are (1) wind- and precipitation-influenced surface roughening of a wet snowpack, and (2) the deposition of new wet snow at lower elevation and its subsequent retreat up-glacier. An abrupt decrease in regional temperature during October is thought to reduce the snow wetness and increase grain-size. The changes in the radar-defined glacier zones due to the April precipitation event are subtle, while the October temperature drop causes significant backscatter increases. Our results suggest that trends in HPS glacier surface and near-surface conditions observable from spaceborne SARs are not significantly masked by precipitation events.

scholarly journals The South-American distribution and southernmost record of Biomphalaria peregrina - a potential intermediate host of schistosomiasis

2017 ◽  
Author(s):  
Alejandra Rumi ◽  
Roberto Eugenio Vogler ◽  
Ariel Anibal Beltramino
Keyword(s):  
16S Rrna ◽  
South America ◽  
Potential Distribution ◽  
Phylogenetic Analyses ◽  
Distribution Model ◽  
South American ◽  
Intermediate Hosts ◽  
Morphological Examination ◽  
Widespread Species ◽  
Southern Patagonia

Schistosomiasis remains a major parasitic disease, endemic in large parts of South America. Five neotropical species of Biomphalaria have been found to act as intermediate hosts of Schistosoma mansoni in natural populations, while others have been shown to be susceptible in experimental infections, although not found infected in the field. Among these potential intermediate hosts, Biomphalaria peregrina represents the most widespread species in South America, with confirmed occurrence records from Venezuela to northern Patagonia. In this study, we report the southernmost record for the species at the Pinturas River, in southern Patagonia, which finding implies a southward reassessment of the limit for the known species of this genus. The identities of the individuals from this population were confirmed through morphological examination, and by means of two mitochondrial genes, cytochrome oxidase subunit I (COI) and 16S-rRNA. With both markers, phylogenetic analyses were conducted in order to compare the genetic background of individuals from the Pinturas River with previously genetically characterized strains of B. peregrina from various South American locations. In addition, we produced a potential distribution model of B. peregrina in South America and identified the environmental variables that best predict that distribution. The model was estimated through a maximum entropy algorithm and run with occurrence points obtained from several sources, including the scientific literature and international databases, along with climatic and hydrographic variables. Different phylogenetic analyses with either the COI or 16S-rRNA sequences did not conflict, but rather gave very similar topological organizations. Two major groups were identified, with sequences from the Pinturas River grouping together with haplotypes from subtropical and temperate regions. The model developed had a satisfactory performance for the study area. We observed that the areas with higher habitat suitability were found to be mainly linked to subtropical and temperate regions of South America between 15° and 45° south latitude, with different moderate- and low-suitability areas outside this range. We also identified the coldest temperatures as the main predictors of the potential distribution of this snail. Susceptibility surveys would be required to evaluate if southern populations of B. peregrina still retain their potential as intermediate hosts of S. mansoni.

scholarly journals ENSO-triggered floods in South America: correlation between maximum monthly discharges during strong events

2018 ◽  
Author(s):  
Federico Ignacio Isla
Keyword(s):  
South America ◽  
Saline Water ◽  
High Water ◽  
Water Levels ◽  
South American ◽  
Porto Alegre ◽  
Large Cities ◽  
The Pacific ◽  
Southern Patagonia ◽  
The Pacific Ocean

Abstract. ENSO-triggered floods altered completely the annual discharge of many watersheds of South America. Anomalous years as 1941, 1982–83, 1997–98 and 2015–16 signified enormous fluvial discharges draining towards the Pacific Ocean, but also to the Atlantic. These floods affected large cities built on medium-latitudinal Andes (Lima, Quito, Salta), but also those located at floodplains, as Porto Alegre, Blumenau, Curitiba, Asunción, Santa Fe and Buenos Aires. Maximum discharge months are particular and easily distinguished along time series from watersheds located at the South American Arid Diagonal. At watersheds conditioned by precipitations delivered from the Atlantic or Pacific anti-cyclonic centers, the ENSO-triggered floods are more difficult to discern. The floods of 1941 affected 70,000 inhabitants in Porto Alegre. In 1983, Blumenau city was flooded during several days; and the Paraná River multiplied 15 times the width of its middle floodplain. That year, the Colorado River in Northern Patagonia connected for the last time to the Desagûadero – Chadileuvú – Curacó system and its delta received saline water for the last time. During strong ENSO years the water balances of certain piedmont lakes of Southern Patagonia are modified as the increases in snow accumulations cause high water levels, with a lag of 13 months. The correlation between the maximum monthly discharges of 1982–83 and 1997–98 at different regions and watersheds indicates they can be forecasted for future floods triggered by same phenomena. South American rivers can be classified therefore into ENSO-affected and ENSO-dominated for those within the Arid Diagonal that are exclusively subject to high discharges during those years.

scholarly journals Effects of weather events on X-SAR returns from ice fields: case-study of Hielo Patagónico Sur, South America

1997 ◽  
Vol 24 ◽  
pp. 367-374 ◽  
Author(s):  
Richard R. Forster ◽  
Laurence C. Smith ◽  
Bryan L. Isacks
Keyword(s):  
South America ◽  
Space Shuttle ◽  
Temperature Drop ◽  
Precipitation Event ◽  
Glacier Surface ◽  
Abrupt Decrease ◽  
Near Surface ◽  
Surface Conditions ◽  
Southern Patagonia ◽  
Wet Snow

The space-shuttle-based SIR-C/X-SAR synthetic aperture radar (SAR) imaged part of Hielo Patagónico Sur (HPS; southern Patagonia ice field, South America) for five successive days during missions in April and October 1994. A significant meteorological event occurred during each mission, including a major storm in April and a sharp temperature decrease in October. Changes in backscatter are observed for both episodes in X-SAR returns from the mid-portions of one of the two large outlet glaciers in the study area. Ground-station and satellite meteorological, and hydrological data are combined with the daily X-SAR images to interpret changes in glacier surface conditions caused by meteorological events. Effects interpreted from the April storm are (1) wind- and precipitation-influenced surface roughening of a wet snowpack, and (2) the deposition of new wet snow at lower elevation and its subsequent retreat up-glacier. An abrupt decrease in regional temperature during October is thought to reduce the snow wetness and increase grain-size. The changes in the radar-defined glacier zones due to the April precipitation event are subtle, while the October temperature drop causes significant backscatter increases. Our results suggest that trends in HPS glacier surface and near-surface conditions observable from spaceborne SARs are not significantly masked by precipitation events.

Recent Glacier Variations in the Southern Patagonia Icefield, South America

1997 ◽  
Vol 29 (1) ◽  
pp. 1 ◽  
Author(s):  
Masamu Aniya ◽  
Hiroaki Sato ◽  
Renji Naruse ◽  
Pedro Skvarca ◽  
Gino Casassa
Keyword(s):  
South America ◽  
Southern Patagonia

scholarly journals The South-American distribution and southernmost record of Biomphalaria peregrina - a potential intermediate host of schistosomiasis

2017 ◽  
Author(s):  
Alejandra Rumi ◽  
Roberto Eugenio Vogler ◽  
Ariel Anibal Beltramino
Keyword(s):  
16S Rrna ◽  
South America ◽  
Potential Distribution ◽  
Phylogenetic Analyses ◽  
Distribution Model ◽  
South American ◽  
Intermediate Hosts ◽  
Morphological Examination ◽  
Widespread Species ◽  
Southern Patagonia

Schistosomiasis remains a major parasitic disease, endemic in large parts of South America. Five neotropical species of Biomphalaria have been found to act as intermediate hosts of Schistosoma mansoni in natural populations, while others have been shown to be susceptible in experimental infections, although not found infected in the field. Among these potential intermediate hosts, Biomphalaria peregrina represents the most widespread species in South America, with confirmed occurrence records from Venezuela to northern Patagonia. In this study, we report the southernmost record for the species at the Pinturas River, in southern Patagonia, which finding implies a southward reassessment of the limit for the known species of this genus. The identities of the individuals from this population were confirmed through morphological examination, and by means of two mitochondrial genes, cytochrome oxidase subunit I (COI) and 16S-rRNA. With both markers, phylogenetic analyses were conducted in order to compare the genetic background of individuals from the Pinturas River with previously genetically characterized strains of B. peregrina from various South American locations. In addition, we produced a potential distribution model of B. peregrina in South America and identified the environmental variables that best predict that distribution. The model was estimated through a maximum entropy algorithm and run with occurrence points obtained from several sources, including the scientific literature and international databases, along with climatic and hydrographic variables. Different phylogenetic analyses with either the COI or 16S-rRNA sequences did not conflict, but rather gave very similar topological organizations. Two major groups were identified, with sequences from the Pinturas River grouping together with haplotypes from subtropical and temperate regions. The model developed had a satisfactory performance for the study area. We observed that the areas with higher habitat suitability were found to be mainly linked to subtropical and temperate regions of South America between 15° and 45° south latitude, with different moderate- and low-suitability areas outside this range. We also identified the coldest temperatures as the main predictors of the potential distribution of this snail. Susceptibility surveys would be required to evaluate if southern populations of B. peregrina still retain their potential as intermediate hosts of S. mansoni.

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