Los Tuxtlas is a region in the south of the Mexican state of Veracruz.
Politically it refers to four municipalities: Catemaco, San Andrés Tuxtla, Santiago Tuxtla and Hueyapan de Ocampo. It also refers to a high complex natural ecosystem, an isolated volcanic mountain range next to the Gulf of Mexico, home to the northern edge of tropical rainforest in the Americas. Although seriously deforested, most of it is under protection as the Los Tuxtlas Biosphere Reserve, which stretches over eight municipalities, centering on the four mentioned above. The area's early history was influenced by the Olmecs but had its own trajectory. In the colonial period, the population became a mix of indigenous, African and European. For all its history until the present, it has been rural and agricultural. Today one of its notable crops is tobacco. However, conservation efforts since the 1970s have promoted ecotourism, especially in Catemaco.
Geography and environment
Topography
The Sierra de Los Tuxtlas is a coastal volcanic mountain range that runs parallel with the Gulf of Mexico, eighty km long and fifty km at its widest, covering an area of 3,300km2. It is completely isolated from any other mountain range, surrounded by the Papaloapan and Coatzacoalcos River basins. It is the easternmost point of the Trans-Mexican Volcanic Belt and has high geological and ecological complexity, subject to volcanic forces as well as erosion from wind and rain off the Gulf of Mexico.
The area is still volcanically active, with evidence of activity dating back at least 800,000 years, with the oldest volcano being Santa Marta.
The most active are San Martín Tuxtla (Tiltépetl, 1,680masl), Santa Marta (1,680masl), San Martín Pajapan (1,180masl), Cerro de Campanario (1540masl), Cerro Mono Blanco (1,380masl), Cerro de Vigía or Cerro Tuxtla (860masl) and Cerro Blanco (640masl). The last recorded eruptions were of San Martín Tuxtla in 1664 and 1793. There are many other volcanic cones with forty containing crater lakes. The volcanic activity has shaped the mountain range as well as water flow.
The mountain range ends abruptly at the sea, which makes for low cliffs and small beaches, the latter usually at the mouths of rivers and streams. The main beaches include the Barra de Sontecomapan, a strip of land that mostly separates the Gulf from the Sontecomapan Lagoon and Monte Pío, where two rivers empty into the sea.
Vegetation
Biologically speaking, Los Tuxtlas is one of the most important regions in Mexico, a complex mixture of vegetation covering mountains and sea coast and includes the northern limit of tropical rainforest in the Americas. The dominant ecosystem is tropical rainforest but it is mixed with other vegetation. In general, the region has eleven kinds of vegetation: high perennial rainforest, medium perennial rainforest, low perennial rainforest, cloud forest, holm oak forest, pine forest, savannah, dunes, areas of tall grass (acahual) and grassland. An important part of its flora and fauna are shared with areas to the south into Central America and South America .
However, the natural vegetation has been severely depleted with estimates of what is left down as far a 5.4%. Despite this, the region is still home to 3,356 species of vascular plants, half the total of the state of Veracruz, and includes 400 species of trees. The wild vegetation is mostly found at the higher elevations, on the volcanos near the coast. Endangered species of fauna include Chironectes minimus, Vampyrum spectrum, Alouatta palliate, Ateles geoffroyii, Cyclopes didactylus. There are fifteen plant species that are endemic to the region.
Climate
Los Tuxtlas is one of the rainiest areas of Mexico. Average annual rainfall is between 1,500 and 4,500mm and average annual temperature is between 8 and 36C.