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Transversal Neo-Volcanic System

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NameColor on MapCEC Code‡
Interior Plains and Piedmonts with Grasslands and Xeric Shrub13.4.1
Hills and Sierras with Conifer, Oak, and Mixed Forests13.4.2

† Status: ✓ = Complete ○ = Needs Image … = Incomplete ∅ = Stub Only

This code refers to the CEC's Level 3 ecoregion codes for North America, see here.


Partially Complete
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Complete w/ Images

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About the Transversal Neo-Volcanic System

The Transversal Neo-Volcanic System is a level II ecoregion in Mexico. It runs east-west along a range of mountains that are called the Trans-Mexican Volcanic Belt, and locally referred to as the Sierra Nevada.

This region is geologically distinct from the two older Sierra Madre mountain ranges that run Northwest-southeast, although it intersects both of these mountain ranges. This area is volcanically active, and reaches higher elevations (the highest being over 18,400 feet/5,636m), with year-round snow on many of the highest peaks. This region has the highest-altitude regions in Mexico. The volcanic peaks are interspersed among large plateaus. The lower elevations in this region are still higher than those in the Mexican High Plateau to the North.

Most of this region has a subtropical highland climate, although it is variable throughout the region, both owing to elevation changes, the North American Monsoon, and the Intertropical Convergence Zone. Rainfall is strongly seasonal, concentrated in summer, with almost no rainfall in winter. Seasonality of temperature is minimal, but winter lows are colder at higher elevations. Precipitation is also higher at higher elevations. Low-lying flatlands have a semi-arid climate with scrublands, cacti, and succulents, and can experience frost in winter, but rarely significant snowfall. Higher elevations have temperate forests, with higher rainfall and more common frosts in winter, and include both conifers and broadleaf evergreens.

This is the most populous region of Mexico, containing the Mexico city metropolitan area, as well as the large cities Puebla and Tlaxcala, the medium-sized city of Toluca, and many smaller cities.

This region borders many wildly different ecoregions. The largest borders are to the north, with the Mexican High Plateau, and to the south with the Interior Depressions. The easternmost portion borders the Eastern Sierra Madre to the north, and the Humid Gulf of Mexico Coastal Plain and Hills to the east. To the south, this region borders the Southern Sierra Madre in three separate locations. There is a small border to the northwest with the Western Pacific Plain and Hills, and another with the Southern Pacific Coastal Plain and Hills. The westernmost part of this region borders a narrow piece of the Western Pacific Coastal Plain, Hills, and Canyons to the north.