scholarly journals Using Growth Forms to Predict Epiphytic Lichen Abundance in a Wide Variety of Forest Types

Diversity ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 51 ◽  
Author(s):  
Gregorio Aragón ◽  
Isabel Martínez ◽  
Pilar Hurtado ◽  
Ángel Benítez ◽  
Clara Rodríguez ◽  
...  
Keyword(s):  
South America ◽  
Habitat Degradation ◽  
South American ◽  
Growth Forms ◽  
Linear Regression Models ◽  
Epiphytic Lichen ◽  
Diversity Assessment ◽  
Time Required ◽  
Central South ◽  
Lichen Growth

Epiphytic richness is continuously declining due to forest fragmentation, logging, burning, agriculture, and livestock. The rate of species loss caused by habitat degradation and loss is more pronounced in Central and South America. Considering the extreme difficulty and time required to identify the more inconspicuous species, rapid diversity assessment methods need to be extrapolated throughout the world. This study correlated lichen growth forms and total epiphytic abundance across 119 forests located in Europe and Central-South America. A total of 54 papers were selected from specific databases focused on lichens. Additionally, data from several unpublished ecological studies were included. Linear regression models showed that epiphytic lichen abundance was highly and positively correlated with the number of growth forms at all geographical levels considered (i.e., Central-South American and European forests, and the combination of both). Thus, the use of growth forms may provide an alternative and complementary way to evaluate epiphytic diversity because most growth forms have cosmopolitan distribution and are easily recognizable.

scholarly journals Speleothem record of geomagnetic South Atlantic Anomaly recurrence

2018 ◽  
Vol 115 (52) ◽  
pp. 13198-13203 ◽  
Author(s):  
Ricardo I. F. Trindade ◽  
Plinio Jaqueto ◽  
Filipe Terra-Nova ◽  
Daniele Brandt ◽  
Gelvam A. Hartmann ◽  
...  
Keyword(s):  
South America ◽  
South Atlantic ◽  
South American ◽  
The South ◽  
South Atlantic Anomaly ◽  
Core Mantle Boundary ◽  
Directional Variation ◽  
Relative Paleointensity ◽  
Synthetic Models ◽  
Central South

The diminishing strength of the Earth’s magnetic dipole over recent millennia is accompanied by the increasing prominence of the geomagnetic South Atlantic Anomaly (SAA), which spreads over the South Atlantic Ocean and South America. The longevity of this feature at millennial timescales is elusive because of the scarcity of continuous geomagnetic data for the region. Here, we report a unique geomagnetic record for the last ∼1500 y that combines the data of two well-dated stalagmites from Pau d’Alho cave, located close to the present-day minimum of the anomaly in central South America. Magnetic directions and relative paleointensity data for both stalagmites are generally consistent and agree with historical data from the last 500 y. Before 1500 CE, the data adhere to the geomagnetic model ARCH3K.1, which is derived solely from archeomagnetic data. Our observations indicate rapid directional variations (>0.1°/y) from approximately 860 to 960 CE and approximately 1450 to 1750 CE. A similar pattern of rapid directional variation observed from South Africa precedes the South American record by 224 ± 50 y. These results confirm that fast geomagnetic field variations linked to the SAA are a recurrent feature in the region. We develop synthetic models of reversed magnetic flux patches at the core–mantle boundary and calculate their expression at the Earth’s surface. The models that qualitatively resemble the observational data involve westward (and southward) migration of midlatitude patches, combined with their expansion and intensification.

scholarly journals Pleistocene Mammals from Pampean Region (Argentina). Biostratigraphic, Biogeographic, and Environmental Implications

Quaternary ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 15
Author(s):  
José Luis Prado ◽  
María Teresa Alberdi ◽  
Jonathan Bellinzoni
Keyword(s):  
South America ◽  
The State ◽  
Historical Study ◽  
South American ◽  
Environmental Implications ◽  
Sedimentary Sequences ◽  
Pampean Region ◽  
Mammalian Faunas ◽  
Pleistocene Mammals ◽  
Fossil Records

The Pampean Region contains sedimentary sequences with abundant mammal fossil records, which constitute the chronological outline of the Plio–Pleistocene of South America. These classic localities have been used for more than a century to correlate with other South American regions. Throughout this time, a series of misinterpretations have appeared. To understand the stratigraphic significance of these localities and the geochronological situation of each unit referring to the Pleistocene, a critical historical study of the antecedents was carried out, evaluating the state of each unit. The biostratigraphic studies of the Pampean Region’s mammalian faunas improved the understanding of biogeographic changes taking into account the environmental fluctuations of the Pleistocene.

scholarly journals An Overview of Equine Influenza in South America

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 888
Author(s):  
Cecilia Olguin-Perglione ◽  
María Edith Barrandeguy
Keyword(s):  
South America ◽  
Disease Surveillance ◽  
Economic Losses ◽  
South American ◽  
Respiratory Pathogens ◽  
Equine Influenza Virus ◽  
Equine Influenza ◽  
Vaccine Manufacturer ◽  
Gene Level ◽  
Control Procedures

Equine influenza virus (EIV) is one of the most important respiratory pathogens of horses as outbreaks of the disease lead to significant economic losses worldwide. In this review, we summarize the information available on equine influenza (EI) in South America. In the region, the major events of EI occurred almost in the same period in the different countries, and the EIV isolated showed high genetic identity at the hemagglutinin gene level. It is highly likely that the continuous movement of horses, some of them subclinically infected, among South American countries, facilitated the spread of the virus. Although EI vaccination is mandatory for mobile or congregates equine populations in the region, EI outbreaks continuously threaten the equine industry. Vaccine breakdown could be related to the fact that many of the commercial vaccines available in the region contain out-of-date EIV strains, and some of them even lack reliable information about immunogenicity and efficacy. This review highlights the importance of disease surveillance and reinforces the need to harmonize quarantine and biosecurity protocols, and encourage vaccine manufacturer companies to carry out quality control procedures and update the EIV strains in their products.

scholarly journals Comparison of <i>H</i> component geomagnetic field time series obtained at different sites over South America

2018 ◽  
Vol 36 (3) ◽  
pp. 937-943 ◽  
Author(s):  
Maurício J. A. Bolzan ◽  
Clezio M. Denardini ◽  
Alexandre Tardelli
Keyword(s):  
South America ◽  
Geomagnetic Field ◽  
Phase Coherence ◽  
South American ◽  
Data Set ◽  
Geomagnetism And Paleomagnetism ◽  
Strong Phase ◽  
Geomagnetic Fields ◽  
Time Variations ◽  
Physical Phenomena

Abstract. The geomagnetic field in the Brazilian sector is influenced by the South American Magnetic Anomaly (SAMA) that causes a decrease in the magnitude of the local geomagnetic field when compared to other regions in the world. Thus, the magnetometer network and data set of space weather over Brazil led by Embrace are important tools for promoting the understanding of geomagnetic fields over Brazil. In this sense, in this work we used the H component of geomagnetic fields obtained at different sites in South America in order to compare results from the phase coherence obtained from wavelet transform (WT). Results from comparison between Cachoeira Paulista (CXP) and Eusébio (EUS), and Cachoeira Paulista and São Luis (SLZ), indicated that there exist some phenomena that occur simultaneously in both locations, putting them in the same phase coherence. However, there are other phenomena putting both locations in a strong phase difference as observed between CXP and Rio Grande, Argentina (RGA). This study was done for a specific moderate geomagnetic storm that occurred in March 2003. The results are explained in terms of nonlinear interaction between physical phenomena acting in distinct geographic locations and at different times and scales. Keywords. Geomagnetism and paleomagnetism (time variations – diurnal to secular)

Reflections on Contemporary South American Democracies

2001 ◽  
Vol 33 (3) ◽  
pp. 599-609 ◽  
Author(s):  
GUILLERMO O'DONNELL
Keyword(s):  
Latin America ◽  
South America ◽  
National Level ◽  
South American ◽  
Science Literature ◽  
Political Rights ◽  
Opinion Expression ◽  
Definition Of ◽  
The Third World ◽  
Indefinite Future

The occasion of honouring the memory of John Brooks, a great friend of Latin America, has helped me vanquish my initial reluctance to tackle a topic that is as broad, varied and still open-ended as the present situation of democracy in South America. As a first measure of my limitations, with the exception of some references to Costa Rica and Mexico, I will not discuss Central America and the Caribbean, not because I feel these regions are unimportant but because, simply, I do not know enough about them. However, when I feel that I am on sufficiently solid ground so as to refer to Latin America as a whole, I will do so.I begin by noting that in contemporary South America some countries satisfy the definition of political democracy. Those countries share two main characteristics. One is that they hold elections under universal adult franchise that, at least at the national level, are reasonably fair and competitive. These are standard criteria in the political science literature. However, having in mind the experience of Latin America and elsewhere in the third world, I believe that we should add that such elections must be institutionalised. By this I mean that all relevant actors expect that elections of this kind will continue being held in the indefinite future so, whether they like or not, it is rational for them to play democracy, not coup-making or insurrection. We should also stipulate that these elections are decisive, in the sense that those who are elected do occupy the respective offices and end their terms in the constitutionally prescribed way; they are not, as it has happened too often in Latin America, prevented from occupying office or thrown out of it because some supra-constitutional power feels that they are the ‘wrong people’.The second characteristic is the enjoyment of certain political rights, especially of opinion, expression, association, movement and access to a reasonably free and pluralist media. Of course, these and other rights are important per se; in addition, they are instrumental – necessary conditions – for the effectuation of the kind of elections I have just specified.

The heat wave of October 2020 in central South America

2021 ◽  
Author(s):  
Jose A. Marengo ◽  
Tercio Ambrizzi ◽  
Naurinete Barreto ◽  
Ana Paula Cunha ◽  
Andrea M. Ramos ◽  
...  
Keyword(s):  
South America ◽  
Heat Wave ◽  
Central South

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 Impact of enriched analyses on regional numerical forecasts over southeastern South America during SALLJEX

2014 ◽  
Vol 29 (3) ◽  
pp. 315-330
Author(s):  
Yanina García Skabar ◽  
Matilde Nicolini
Keyword(s):  
Data Assimilation ◽  
South America ◽  
Atmospheric Modeling ◽  
South American ◽  
The South ◽  
Low Level ◽  
Positive Effects ◽  
Accumulated Rainfall ◽  
Low Level Jet ◽  
The Impact

During the warm season 2002-2003, the South American Low-Level Jet Experiment (SALLJEX) was carried out in southeastern South America. Taking advantage of the unique database collected in the region, a set of analyses is generated for the SALLJEX period assimilating all available data. The spatial and temporal resolution of this new set of analyses is higher than that of analyses available up to present for southeastern South America. The aim of this paper is to determine the impact of assimilating data into initial fields on mesoscale forecasts in the region, using the Brazilian Regional Atmospheric Modeling System (BRAMS) with particular emphasis on the South American Low-Level Jet (SALLJ) structure and on rainfall forecasts. For most variables, using analyses with data assimilated as initial fields has positive effects on short term forecast. Such effect is greater in wind variables, but not significant in forecasts longer than 24 hours. In particular, data assimilation does not improve forecasts of 24-hour accumulated rainfall, but it has slight positive effects on accumulated rainfall between 6 and 12 forecast hours. As the main focus is on the representation of the SALLJ, the effect of data assimilation in its forecast was explored. Results show that SALLJ is fairly predictable however assimilating additional observation data has small impact on the forecast of SALLJ timing and intensity. The strength of the SALLJ is underestimated independently of data assimilation. However, Root mean square error (RMSE) and BIAS values reveal the positive effect of data assimilation up to 18-hours forecasts with a greater impact near higher topography.

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