SIERRA MADRE DEL SUR: LOCATION, RELIEF, CLIMATE, FLORA - GEOGRAPHY - 2025

The Sierra Madre del Sur is the southern part of the extensive Sierra Madre mountain range that runs throughout Mexico. Although the western region is the one with the greatest variety of inhabitants as well as fauna and flora, the forests of the Sierra Madre del Sur are rich in small species and plants exclusive to the region.

The Sierra Madre was fully formed approximately 66 million years ago, in a creation process that lasted about 190 million years. The elevation and creation of all the terrain that rose to form this range occurred in conjunction with the formation of the Rocky Mountains of the United States.

Location

The geological process that led to the creation of the Sierra Madre left an apparent division into three parts.

The Sierra Madre Oriental owes its shape to various earth movements in the rocks that occurred in the Cretaceous period. In central Mexico, there was a lot of volcanic activity in the past that shaped the mountains of the region.

The Sierra Madre del Sur is divided from the rest of the Mexican mountains and presents peculiar characteristics of the area, although similar to those of the rest.

Elevation

The southern part of the mountain range extends over 1000 kilometers in the southern territory of Mexico, from Michoacán to Guerrero, on the Isthmus of Tehuantepec located in eastern Oaxaca. The highest point of the Sierra Madre del Sur reaches almost 4 kilometers above sea level.

This part of the mountain range joins the Transversal Volcanic Axis in central Mexico, but in the west it is divided by the Balsas River which later connects with the Tepalcatepec River. There is only one highway that crosses this geographic expansion from Acapulco to Mexico City.

Although separated by a river, the southern mountains of Michoacán and Coalcomán are also considered part of the Sierra Madre del Sur mountain range.

Relief

The deepest part of the Sierra Madre del Sur is delimited by a narrow and discontinuous coastal plain that stretches across southwestern Mexico and the Balsas River to the north.

A wide variety of narrow ridges and steep valleys with quite a few geological irregularities make up the Southern Highlands. Many of the ridges of these mountains reach considerable elevations, and are quite irregular in shape with rocks present in various areas.

Volcanic activity

The rest of the Sierra Madre has quite a lot of evidence of past volcanic activity, but the volcanic cover of the Sierra Madre del Sur has been lost over time and no longer has the high presence it had millions of years ago.

However, at the bottom of these mountains you can find dissected rocks that are millions of years old. It is perhaps the oldest dried rock in Mexico.

There are very few flat areas in these mountains, presenting irregularities throughout their territory. To the south of this area of ​​the Sierra Madre there is an abrupt cut that divides this formation and the joint with the ocean. This part of the sierra stands out from the rest and rises above the entire isthmus of Tehuantepec.

Weather

The climate of the Sierra Madre del Sur is mainly humid and warm. However, this also varies with altitude. The lower areas of the Sierra Madre tend to have a relatively hot climate during the day and a bit cooler at night, dropping the temperature to around 22 degrees Celsius.

In the higher areas there are high mountain ecosystems, but it is not completely cold. The temperature remains warm and in some areas it is considered semi-cold.

Flora

Orchids

The Sierra Madre del Sur presents a unique biodiversity of this area, especially with regard to its flora. In all its extension there are 350 different species of orchids unique to this part of the mountain, which cannot be seen anywhere else in the world.

Coniferous trees

Mainly it presents a gigantic extension of coniferous trees, such as the pine oak forests of the Sierra Madre del Sur. This forested extension has an expansion of approximately 61,000 square kilometers, being the main habitat of hundreds of plants and small animals unique to the region.

This forest extends along the entire coast of Mexico and occupies almost the entire Sierra Madre del Sur.

Each type of tree grows at different altitudes, between 1,900 and 3,000 meters in height in relation to sea level. The forest is categorized as a coniferous subtropical ecoregion and is one of the most extensive forested expansions that can be found in the entire Mexican territory.

Fauna

The Sierra Madre del Sur presents a great biological variety in its complex rock formations.

Butterflies, beetles and reptiles

This area has one of the most diverse populations of butterflies and beetles in all of Mexico. In addition, it has a large number of unique reptiles with its unique species of toads, frogs and salamanders.

Mammals

The mammals of the Sierra Madre del Sur are similar to those of the western mountain range, but it also has unique species of bats, mice, skunks, and shrews.

Birds

The region is especially rich in bird species: it features unique species of orioles, eagles, and nutcracker birds.

All this makes the Sierra Madre del Sur one of the richest biogeographic areas in the world.

References

1. Sierra Madre Mountain System, Henry J. Bruman George C. Engerrand, (nd). Taken from Britannica.com
2. Mexico, Gordon R. Willey Michael C. Meyer Howard F. Cline Angel Palerm Ernst C. Griffin Henry Bamford Parkes, February 3, 2018. Taken from Britannica.com
3. Sierra Madre del Sur pine-oak forests animal and plant species, (nd). Taken from globalspecies.com
4. Sierra Madre del Sur - Physiographic Province. (nd). Taken from paratodomexico.com
5. Sierra Madre del Sur pine-oak forests, (nd). June 24, 2017. Taken from Wikipedia.com
6. Sierra Madre del Sur pine-oak forests, (nd). June 24, 2017. Taken from Wikipedia.com