The Neotropical or neotropic bioregion Is the name that receives an extension of territory, ecosystems, fauna and flora that extends from Mexico to the south of Brazil, covering the whole of Central America, the Caribbean and almost all South America, although some studies include the whole Southern Cone .

The name of bioregion is attributed to it from the branch of biogeography and serves to differentiate it from other great bioregions of the world.

The neotropic is characterized by the high presence of tropical forests, great animal and vegetable riches; Seasons of precipitation and droughts well marked throughout the year.

Due to the extension of what is considered the tropical bioregion, the territory that corresponds to each nation and its Different ecosystems May have specific traits that may not manifest in the same way in other parts of the same ecozone.

The Amazon, which once represented one-third of South America; The Cerrado and the Atlantic forest are the largest plant bodies of the Neotropics.

Geologically, the neotropic is distributed along three tectonic plates: the North American, South American and Caribbean plate.

Included in the tropical region are some mountainous or wooded territories with temperate characteristics, such as the Patagonian or Valdivian forest.

You may also be interested in The world's natural regions .

Origin of the neotropical or neotropic bioregion

The origin of the qualities that characterize the neotropical zone dates back to the Paleozoic-Mesozoic period (between 200 and 135 million years), when the separation of the mega continent Pangea resulted in two large bodies: Laurasia and Gondwana.

What today corresponds to South America was stuck to the African continent, separating during the Cretaceous; For this reason the neotropic until today shares similarities in vegetation with alagunas African regions.

The consolidation of the American continent materialized during the Upper Cretaceous, 90 million years ago. The gradual rise of the Andes mountain range began to generate climatic changes, drier and cooler, in the hitherto unchanged neotropical relief.

During millions of years, the South of the American continent presented / displayed many periods of glaciation, before being settled a temperate climate with periodic precipitations.

Studies estimate that the neotropical region presented at some time characteristics different from the present:

1- A sea level lower than the current one (up to 120 meters less), and the possibility that some current islands were connected to the continent.

2 - The limit of the páramo descended until 1500 meters in the Andean region.

3- The average sea temperature was lower.

4- The end of the glacial period generated a drier climate.

Physical and climatic features of the neotropic

The Andes mountains Is the main natural component, or macroenvironment, that divides the South American continent in the east-west direction, presenting an Amazon block and another Andean, of greater diversity in altitudes and valleys.

The other macroambientes represented in the neotropical region are the one of Brazil and Guayana; The sedimentary depressions of the Amazon, the Orinoco, and Chaco-Pampeana plain; The extra-Andean Patagonia; The Monte and Sierra Pampeana.

The division in both blocks mentioned above, and its proximity to the equator, directly influenced the fauna and flora of each subregion within the American continent.

In most of the continent and the Caribbean dominate the tropical climates, whereas to the south dominates the maritime climates.

Research has come to divide the Neotropics into 47 different provinces across the continent in order to highlight the natural differences that the different portions of territory present, despite being under a kind of common climate mantle.

The importance of these differentiations evidences situations within the neotropic related to the index of precipitations and droughts in different zones.

The western region of Colombia can present a rainfall index of up to 9000mm annually, while the Amazon basin presents an average of 2000mm a year.

Wind directions are also a factor, and this is where the Andes Mountains play a key role. The Atlantic winds keep humid climates in the Amazon block, for example.

Neotropical vegetation

The natural conditions of the neotropical bioregion do not allow it to present an equitable plant distribution in all its territories; Reflecting the climatic zonation of the region.

However, the neotropical plant variety is one of the richest on the planet. The vegetation is characterized as follows:

1- Tropical forests (Brazil, Ecuador, Central America and southern Mexico), represent 44% of the region, with tropical rainforests predominating, followed by deciduous moist forests and mountain forests. This is the most common habitat of Neotropical fauna.

2 - Savannahs (Brazil, Colombia, Venezuela, Bolivia), cover 12% of the Neotropical region and present more defined periods of drought. It is one of the most productive ecosystems (agriculture, livestock) and their quality as habitat depend on the type of soil and relief that they present.

3- Andean herbaceous formations (Costa Rica, Peru) cover the Andean valleys and plateaus above 3500 meters of altitude, distributing along the region in a north-south direction.

4- The Argentine pampas and temperate meadows, present a desert gradient, steppes and dry scrubs. Vegetation not only present in the Southern Cone, but also in some regions of Mexico. They are not very productive habitats, although they present a particular fauna.

5- Wetlands are formations between terrestrial and aquatic ecosystems, such as riparian forests, mangroves and flooded savannas. They represent 4% of the entire neotropical region.

Fauna

Like the vegetation, the animal diversity in the neotropic is very rich, but it is marked by the immediate environmental conditions, resulting in the presence of certain species in specific territories and their absence in others, as well as differences between species of the same family .

The most species of the neotropic species belong to mammals; Marsupials, raccoons, rodents, primates, bears (front bear), felines (yaguarete, jaguar, cunaguaro), bats, artiodactyls (deer, gazelle, wild boar), perisodactyls (horse, , Lagomorphs (rabbit), xenarthus (anteater, lazy, armadillo), sirenios (sea dog, manatee).

Among the birds you can find species of the family of the condor and the eagle, and small wild birds such as cocuyo or cardinal.

References

Antonelli, A., & Sanmartín, I. (2011). Why are there so many plant species in the Neotropics? Taxon , 403-414.

Eisenberg, J.F. (1989). Mammals of the Neotropics. Chicago: University of Chicago Press.

Ojasti, J. (2000). Management of Neotropical Wildlife. Washington, D.C.: Smithsonian Institution.

Rull, V. (2011). Neotropical biodiversity: timing and. Trends in Ecology and Evolution , 1-6.

Udvardy, M.D. (1975). A Classification of the Biogeographical Provinces of the World. Morges: International Union for Conservation of Nature and Natural Resources.