scholarly journals Neotropical moss floras: Species common to North and South America.

1995 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Claudio Delgadillo M.

North and South America share about 675 species that show two basic patterns, namely, those with a continuous range and those with a disjunct distribution. Both may have resulted from step-bystep migration, but the latter, including 118 species, may be due to break up of previous distributions by post-Tertiary tectonic and climatic changes or by long-distance dispersal.

Atlantic Wars ◽  
2020 ◽  
pp. 125-151
Author(s):  
Geoffrey Plank

Chapter 6 examines the shared experiences of communities in the Caribbean, North and South America, Africa, and Europe in fielding men for combat on land. After discussing the first Spanish campaigns on Hispaniola, the chapter analyzes the challenges of recruiting, training, arming, and feeding warriors, maintaining discipline, demobilizing fighting men, and coping with combat deaths. These challenges are common among all societies engaged in warfare, and they were complicated across the Atlantic world in the early modern era as long-term, long-distance military deployments placed new burdens on fighting men and their communities, straining the logistical capacities of villages and empires.


2020 ◽  
Vol 110 (6) ◽  
pp. 1124-1131
Author(s):  
Mary Ortiz-Castro ◽  
Terra Hartman ◽  
Teresa Coutinho ◽  
Jillian M. Lang ◽  
Kevin Korus ◽  
...  

Bacterial leaf streak of corn, caused by Xanthomonas vasicola pv. vasculorum, has been present in South Africa for over 70 years, but is an emerging disease of corn in North and South America. The only scientific information pertaining to this disease on corn came from work done in South Africa, which primarily investigated host range on other African crops, such as sugarcane and banana. As a result, when the disease was first reported in the United States in 2016, there was very limited information on where this pathogen came from, how it infects its host, what plant tissue(s) it is capable of infecting, where initial inoculum comes from at the beginning of each crop season, how the bacterium spreads from plant to plant and long distance, what meteorological variables and agronomic practices favor disease development and spread, how many other plant species X. vasicola pv. vasculorum is capable of infecting or using as alternate hosts, and if the bacterium will be able to persist in all corn growing regions of the United States. There were also no rapid diagnostic assays available which initially hindered prompt identification prior to the development of molecular diagnostic tools. The goal of this synthesis is to review the history of X. vasicola pv. vasculorum and bacterial leaf streak in South Africa and its movement to North and South America, and highlight the recent research that has been done in response to the emergence of this bacterial disease.


1893 ◽  
Vol 10 (9) ◽  
pp. 401-412 ◽  
Author(s):  
Karl A. von Zittel

In a spirited treatise on the ‘Origin of our Animal World’ Prof. L. Rütimeyer, in the year 1867, described the geological development and distribution of the mammalia, and the relationship of the different faunas of the past with each other and with that now existing. Although, since the appearance of that masterly sketch the palæontological material has been, at least, doubled through new discoveries in Europe and more especially in North and South America, this unexpected increase has in most instances only served as a confirmation of the views which Rutimeyer advanced on more limited experience. At present, Africa forms the only great gap in our knowledge of the fossil mammalia; all the remaining parts of the world can show materials more or less abundantly, from which the course followed by the mammalia in their geological development can be traced with approximate certainty.


The Atlantic Ocean not only connected North and South America with Europe through trade but also provided the means for an exchange of knowledge and ideas, including political radicalism. Socialists and anarchists would use this “radical ocean” to escape state prosecution in their home countries and establish radical milieus abroad. However, this was often a rather unorganized development and therefore the connections that existed were quite diverse. The movement of individuals led to the establishment of organizational ties and the import and exchange of political publications between Europe and the Americas. The main aim of this book is to show how the transatlantic networks of political radicalism evolved with regard to socialist and anarchist milieus and in particular to look at the actors within the relevant processes—topics that have so far been neglected in the major histories of transnational political radicalism of the late nineteenth and early twentieth centuries. Individual case studies are examined within a wider context to show how networks were actually created, how they functioned and their impact on the broader history of the radical Atlantic.


Polar Record ◽  
1989 ◽  
Vol 25 (154) ◽  
pp. 223-228 ◽  
Author(s):  
J. M. B. Smith ◽  
P. Rudall ◽  
P. L. Keage

AbstractSamples from 73 pieces of non-structural driftwood on Heard Island (53°06′S, 73°30′E) were identified to genus or species. Thirty-one belonged to South American species of Nothofagus. The remainder, consisting mostly of conifers especially Picea and Larix, probably came from ships' cargoes. The assemblage is similar to those reported, from smaller samples, on other southern islands. Other items of flotsam, including fishing buoys and drift-cards, are also reported from Heard Island. The significance of driftwood transport from South America to the island in accounting for long-distance dispersal of terrestrial and intertidal organisms is discussed.


2017 ◽  
Vol 13 (11) ◽  
pp. 1515-1526 ◽  
Author(s):  
Aliénor Lavergne ◽  
Fabio Gennaretti ◽  
Camille Risi ◽  
Valérie Daux ◽  
Etienne Boucher ◽  
...  

Abstract. Oxygen isotopes in tree rings (δ18OTR) are widely used to reconstruct past climates. However, the complexity of climatic and biological processes controlling isotopic fractionation is not yet fully understood. Here, we use the MAIDENiso model to decipher the variability in δ18OTR of two temperature-sensitive species of relevant palaeoclimatological interest (Picea mariana and Nothofagus pumilio) and growing at cold high latitudes in North and South America. In this first modelling study on δ18OTR values in both northeastern Canada (53.86° N) and western Argentina (41.10° S), we specifically aim at (1) evaluating the predictive skill of MAIDENiso to simulate δ18OTR values, (2) identifying the physical processes controlling δ18OTR by mechanistic modelling and (3) defining the origin of the temperature signal recorded in the two species. Although the linear regression models used here to predict daily δ18O of precipitation (δ18OP) may need to be improved in the future, the resulting daily δ18OP values adequately reproduce observed (from weather stations) and simulated (by global circulation model) δ18OP series. The δ18OTR values of the two species are correctly simulated using the δ18OP estimation as MAIDENiso input, although some offset in mean δ18OTR levels is observed for the South American site. For both species, the variability in δ18OTR series is primarily linked to the effect of temperature on isotopic enrichment of the leaf water. We show that MAIDENiso is a powerful tool for investigating isotopic fractionation processes but that the lack of a denser isotope-enabled monitoring network recording oxygen fractionation in the soil–vegetation–atmosphere compartments limits our capacity to decipher the processes at play. This study proves that the eco-physiological modelling of δ18OTR values is necessary to interpret the recorded climate signal more reliably.


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