Terrain shapes and bedrock
According to COUNTRYAAH, Mexico has a complex topography with lively volcanic and seismic activity. In central Mexico, the Mexican high plateau is composed of two parts: Mesa del Norte, which extends from the northern border (where the altitude is 1,200 m above sea level) to San Luis Potosí, where Mesa Central takes on and ends at the height of Mexico. City (at an altitude of about 3,000 meters above sea level). Mesa Central is much smoother than Mesa del Norte and can be divided into several streams with fertile black soil type, which are separated by partially eroded volcanic rocks.
The Mexican high plateau is surrounded by mountain ranges. To the west lies the volcanic Sierra Madre Occidental with deep overtaking canyon formation. The Sierra Madre Oriental in the east consists of wrinkled shales and limestones, is strongly shattered and has mountain peaks of about 3,600 m above sea level. A transverse mountain range, Sierra Neovolcánica, south of Mexico City, has several snow-capped volcanic peaks, such as Mexico’s highest point, Citlaltépetl, 5,699m above sea level, Popocatépetl, 5,452m above sea level. and Ixtacihuatl, 5,286 meters above sea level.
At the far end of the sea are coastal plains. The east along the Gulf of Mexico is wide, especially in the north, and has plenty of swamp areas and lagoons. The long coastal plain along the Pacific Ocean is much narrower with coastal terraces and smaller plateaus and borders in its northern part to the California Gulf. The Baja California Peninsula consists of a series of granite fault blocks with heights up to about 3,000 m above sea level. Its eastern side is steep and inaccessible, while its western side is low.
In southern Mexico, the deep valley of the Balsa River separates the Mexican high plateau from the southern highlands with the Sierra Madre del Sur, an approximately 2,300 m high ridge of crystalline rocks. Along the coast south of the Sierra Madre del Sur there are many scenic places, eg. Acapulco. At Mexico’s narrowest point, the approximately 200 km wide Tehuantepecnäset, the altitude is about 275 m above sea level. The Sierra Madre and Chiapas Highlands are the highest elevation areas in the south.
The Yucatán peninsula extends far to the east and is essentially a lowland (lower than 150 m ash) limestone area with numerous ejection caves, gullies and other karst forms.
Due to the dry climate, the watercourses are few and relatively small. The most significant river is the Río Bravo del Norte, which forms part of the border with the United States, where it is called the Rio Grande.
The northern part of Mexico has tropical steppe and desert climate, while in the south there is predominantly savannah climate. The seasons consist of dry season and rainy season. The latter falls in June – October. In the north, less than 250 mm of rain falls per year and on the coastal plains 1,000–1,500 mm per year. The strongly varying relief gives large regional temperature differences.
The country is divided into four altitude zones with different temperature climates. There are tierra caliente (0–1000 m ash, daily mean temperature for the year 25 °C), tierra templada (1,000–2,000 m ash, 19 °C), tierra free (2,000–3,300 m above sea level, 15 °C) and tierra helada (above the snow border, 10 °C).
Plant-and animal life
With over 200,000 species, Mexico is one of the most important countries in the world for biodiversity. Mexico is divided into five ecoregions, based on a larger survey of the whole of North America. A number of north-south oriented mountain ranges, so-called Sierras, affect the climate and propagation of plants and animals, which in turn creates an intricate network of different forest types and ecoregions, often with a high proportion of endemic species.
The northern part
The North American Great Plains extend from southern Canada throughout the central United States into northeastern Mexico. In the Mexican part, the plains are often overgrown with bush vegetation, for example mesquite. Only 2 percent of the original nature remains. Within the region are the only remaining populations of the Mexican prairie dog (Cynoʹmys mexicaʹnus). Sparrow (Spizeʹlla wortheʹni) is a highly threatened bird with the same breeding range. The lowland area is bounded to the west by the Sierra Madre Oriental mountain range – a form of semi-arid highland area with oak and pine forests with, among other things, knitland woodpecker (Picoiʹdes stricklaʹndi) and band- tailed deer (Buʹteo albonotaʹtus). The Cumbres de Monterrey National Park is guarding an important part of the mountain range. Here lives black bear, cougar, coyote, black-tailed deer and white-tailed deer. Among the birds are noticed pine parakeets (Rhynchoʹpsitta terriʹsi), which are threatened and have a very limited distribution.
The desert occupies a significant portion of Mexico’s land area. It is divided into three main areas – Chihuahua, Sonora and Baja California. The Chihuahua Desert extends from the southern United States far south into Mexico and is one of the richest dry regions in the world. Among the 3,500 plant species, around 1,000 are endemic, many of which are cactus plants. Shrubs of the creosote shrub (Larreʹa) often dominate the vegetation. It is a high plateau of 1,100-1,500 m above sea level with higher rainfall and cooler climates than in many other dry regions of the world, which benefits many plants and animals. Among the mammals are jaguar, gray fox, necklace pointer, fork antelope, kangaroo jumping mice, desert rabbit (Sylvilaʹgus auduboʹnii) and black-tailed donkey hair (Leʹpus califoʹrnicus). Bird life is relatively rich in species specifically adapted to the local conditions, including Greater Roadrunner (Geoco’ccyx california’nus), bågnäbbad Thrasher (Toxosto’ma curviro’stre), cactus owl (Micrathe’ne whitne’yi) and Cactus (Campylorhy’nchus brunneica’pillus). Day butterflies, spiders, scorpions, ants, lizards and snakes show a large proportion of endemics. The Chihuahua Desert also has the largest number of bee species in Mexico.
In the western part of the Chihuahua desert, Janos biosphere reserve is located in the state of Chihuahua. Just before the inauguration in 2009, the first specimens of American bison from South Dakota were reintroduced after being eradicated in Mexico. Bison plays an important role for the ecological function through its pasture where open areas are kept free of bushes, which benefits many other species. In the reserve, one of the largest contiguous grasslands in Mexico (220,000 ha) is spreading with North America’s largest population of black- tailed prairie dog (Cynoʹmys ludoviciaʹnus). This species also has a key function for the prairies and several other animals, such as prairie owl (Atheʹne cuniculaʹria) and kingfish (Buteʹo regaʹlis), favored by the presence of prairie dogs. Black-footed ferret (Musteʹla niʹgripes) specializes in living in prairie dog colonies. The reserve also has fork antelope, which is rare in Mexico.
At the northwestern outskirts of the Sierra Madre Oriental, just south of the Rio Grande, is the ‘El Carmen Big Bend Conservation Corridor Initiative’, which covers an area of 1.2 million hectares. Here, a private company bought 87,000 hectares in 2000 and began the laborious work of restoring nature that has been cultivated, used as grazing land and exploited for mineral extraction for more than 100 years. Species that previously existed in the region (for example, a breed of large- horned sheep, Oʹvis canadeʹnsis and vapiti) have been reintroduced and the tribes of white and black-tailed deer have been strengthened as well as increased protection of predators (such as black bears and cougars) by hunting bans. Already after ten years, important parts of the natural flora and fauna have returned.
Sierra Madre Occidental belongs to the group of semi-arid highlands. The mountainous, inaccessible terrain is one of the richest environments in North America. For example, here 23 species of pine grow and around 200 species of oak. Widespread forestry has meant that only about 2 percent of the older, original forests remain. These were the last places in Mexico for grizzly bear and wolf as well as the extinct emperor woodpecker. Among the surviving mammals are black bear, white-tailed deer and several mice and squirrels, including an endemic species of ground squirrels (Callospermoʹphilus madreʹnsis). One of the rarest birds is thick-billed parakeets (Rhynchoʹpsitta pachyrhyʹncha), whose entire world reach is in Sierra Madre Occidental with only around 500 breeding pairs. Other typical birds are durango screams (Cyanocoʹrax dickeʹyi), ear trogon (Euptiloʹtis neoxeʹnus), violet-crowned emerald (Amaziʹlia vioʹliceps), spotted owl (Striʹx occidentaʹlis) and turkey, which prefers higher mountain ranges. The Cascada de Basaseachic National Park, named after the waterfalls that are the second highest in Mexico, lies in the heart of the Sierra Madre Occidental and protects a landscape dominated by oak and pine forests.
On the border between Arizona, California and Mexico is North America’s largest desert – the Sonoran. Saguaro cactus (Carnegieʹa giganteʹa) is especially associated with this place. This plant up to 20 m high can grow up to 150 years old and offers protected nesting sites for a wide range of bird species. Two of the most important are saguaros (Colaʹptes chrysoʹides) and cactus (Melaneʹrpes uropygiaʹlis), which cut out cavities in the cactus. The holes are also used as habitats for many other species, such as cactus owl, cactus garden mosquito and several species of flycatcher. The white or yellow flowers are pollinated by a particular bat species (Leptonycteʹris yerbabueʹnae), who spend the summer months in the desert before moving south to Central America for the winter. Among the mammals that live in the Sonoran Desert are fork antelope, kangaroo jumping mice, thick-horned sheep and coyotes. The poisonous gila lizard thrives here along with a species of desert turtle (Gopheʹrus agaʹssizii).
The Baja California Desert is the third desert area located on the California Peninsula in northwestern Mexico. The area has a mixture of plains, mountains, dunes and coastal lagoons with about 500 different plant species. Several endemic animal species live in the desert – such as a species of kangaroo (Dipodoʹmys graʹvipes), squirrel (Spermoʹphilus atricaʹpillus), xanthus colibri (Basiʹlinna xantuʹsii) and welding yellow chin (Geothlyʹpis beldiʹngi).
In the middle of the western side of the peninsula is El Vizcaíno biosphere reserve with the San Ignacia lagoon. It is Mexico’s largest reserve (2.5 million hectares) with desert and coastal lagoons as well as the northernmost mangrove forests along the Pacific coast. There is a small remnant of an endemic subspecies of fork antelope as well as black-tailed deer and thick-horned sheep. The coast is rich with northern sea elephant, Californian sea lion, four species of sea turtles, gray whale, blue whale, humpback whale, dolphin mongoose (Delphiʹnus capeʹnsis), soot-winged Californianka (Synthliboraʹmphus craveʹri) and Scripps calibria). In the innermost part of the California Gulf, the world’s most threatened marine mammals live: California breeders (Phocoeʹna siʹnus) with fewer than 100 animals (2014). Along the coast of Baja California and the eastern side of the California Gulf, there are a number of important areas (for example, Bahia de Santa Maria) for resting and wintering waders such as tundra snap (Caliʹdris maʹuri), willow snap (Phalaroʹpus tricoʹlor) and prairie spaw (Limoʹsa fedoʹ) Here also lace crocodile lives, especially in connection with remaining mangrove forests.
In the Pacific Ocean west of Baja California are a couple of isolated island groups, two of which are of special importance to nature. Most famous are the volcanic island of Isla Guadalupe with guadalupe fur seal (Arctoceʹphalus townseʹndi), northern sea elephant, white shark, californialira (Puffiʹnus opisthomeʹlas) and guadalupealka (Synthliboraʹmphus hypoleʹucus). There used to be some bird species that are now extinct, for example, guadalupekarakara (Caracaʹra lutoʹsa) and guadalupestorm swallow (Oceanodroʹma macrodaʹctyla). Another archipelago is Isla Natividad with various seals as well as blue-throated cormorants (Phalacrocoʹrax penicillaʹtus), sotalka (Ptychoraʹmphus aleuʹticus) and californialira.
Along the western part of Mexico, from the foothills of the Sierra Madre Occidental and south, a network of various tropical dry forests is spreading. There are about 6,000 different plant species and about 300ʹ bird species. The region is an important wintering area for migratory birds from the US and Canada. Among the more special, local birds are the Mexican sparrow parrot (Foʹrpus cyanopyʹgius), rust-bent chachalaca (Ortaʹlis wagleʹri), sunblown scream (Cyanocoʹrax sanblasiaʹnus) and balex bark (Megascops seductus). The Sierra Madre del Sur mountain range, with peaks up to 3,700 meters, spreads in the southern part and deviates with its pine and oak forests from the region in general. Here you will find several species of hummingbird.
Further inland and parallel to the Sierra Madre del Sur is a belt with Mexico’s highest volcanoes connecting the southern parts of the Sierra Madre Occidental and the Sierra Madre Oriental. Many of the original pine and oak forests are gone due to millennial human exploitation, which has, among other things, given rise to Mexico City. The most famous natural site is Santuario Mariposa Monarco – a 56,000 hectare forest and mountain area set aside as a reserve to protect the millions of monarch butterfliesthat winter here. Each year, monarch butterflies from eastern Canada and the United States move along the Sierra Madre Oriental to this location. Twenty years ago, about 1 billion butterflies were estimated, but since then the number has steadily declined to around 35 million (2014). Initially, many of the most important wintering sites were harmed by forest logging, but since this threat has been overcome, it has been found that the butterflies have been disadvantaged by the decline of the various species of silk herbaceous species (Ascle) pias) which constitute the only food during the summer break in the US and Canada.
Eastern and Southern
Along the central parts of the Gulf of Mexico, a zone of moist, tropical forests with trees such as mahogany and sapotillas is spreading. Here are rare birds such as red-crowned amazon (Amazoʹna viridigenaʹlis), altamiragulhake (Geothlyʹpis flavovelaʹta) and red-necked cardinal (Rhodothraupis celaeno). Jaguar, jaguarundi, ozelot, margaykat and white-nose nose bear are typical of the eco-region. Mexican crocodile (Crocodyʹlus moreleʹtii) is found in coastal freshwater). In the state of Veracruz, near the city of Cardel, adjacent to the Gulf of Mexico, during the fall, the world’s largest concentration of migratory birds of prey with 5 million of 25 species, with the most common being broad-winged (Buʹteo platypteʹrus), turkey (Cathaʹrtes aʹura), prairie (Buʹteo) swainsoʹni) and mississippiglada (Ictiʹnia mississippieʹnsis). Around Veracruz itself is an isolated outpost of dry forests.
The Yucatán Peninsula is a very important place for nature in Mexico. Rainforests, savannas, dry forests, mangrove forests, rivers, wetlands, coastal lagoons, sandy beaches and dunes surrounded by the Caribbean with rich coral reefs create a variety of environments for plants and animals. Around 5,000 plant species are described, of which about 5 percent are endemic. Here are several mammals of tropical origin, such as jaguars, red spider monkey, mantle monkey, guatemalan monkey, Central American tapir, white beard poacher, large- eared opossum (Dideʹlphis marsupiaʹlis), and the endemic deer Mazaʹma pandoʹra belonging to the spider group. Along the coast live lamantine, lace crocodileand Mexican crocodile. The bird life is rich with species such as red macaw (Aʹra macaʹo) and flour amazon (Amazoʹna farinoʹsa) in the forests and many herons, pelicans, gulls and other wetland dependent species especially along the coasts. In Yucatán, land snake (Boʹthrops asper) – one of the world’s most poisonous snakes – is common.
Sian Ka’an biosphere reserve in the eastern part of the peninsula, with its 528,000, has one of the country’s largest and most valuable nature reserves. There you find most animals and plants on the Yucatán Peninsula, including four species of sea turtles. A couple of interesting islands are found in the northeastern peninsula – Isla Mujeres and Isla Holobox – where you can experience whale sharksand a rich marine life with coral reefs, hundreds of fish species and several species of sea turtles. In the southern part of Yucatán, in the state of Chiapas on the border with Guatemala, lies one of the largest contiguous jungle areas in Central America – Lacandon. On nearly 2 million hectares, you will find 1,500 different tree species – some with a height of up to 60 meters – and one third of Mexico’s bird species. Through the size of the area there is a viable tribe of jaguars.
In the Yucatán peninsula there is an interesting natural formation called cenote. Where limestone soil has fallen away, open shafts are formed where the groundwater arrives during the day. This phenomenon is especially pronounced in the Yucatán Peninsula. One of the most well-known areas is in the northern part of the peninsula where a ring of over 900 cenotes has been formed in connection with the Chicxulub crater. At this site, the earth was hit by a meteorite 66 million years ago, which is believed to have contributed to the disappearance of the dinosaurs. In these cenotes, a special world of different animals has been developed with crayfish and different fish, for example two blind species of radiant fish – Ophisteʹrnon infernaʹle and Typhliasiʹna peaʹrsei.