Yucatán Dry Forests Ecoregion (Mexico)

Yucatán Dry Forests Ecoregion (Mexico)

Mon, 04/01/2019 - 16:57
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The Yucatán Dry Forests ecoregion is located on the northwest section of the Yucatán Peninsula. This ecoregion is flat with vegetation consisting of thorn scrub and cacti and, isolated from other dry forests by the sea, constitute a unique island of vegetation in the Gulf of Mexico region.

The Yucatán dry forests ecoregion is located on the northwest section of the Yucatán Peninsula. This ecoregion is flat with vegetation consisting of thorn scrub and cacti and, isolated from other dry forests by the sea, constitute a unique island of vegetation in the Gulf of Mexico region.

The forests grow on a vast portion of flat terrain (<400 m [1,300 ft] above sea level), composed of limestone of coraline origin. Soils are generally young and of calcareous origin; and drainage is extensive, thus the soils hardly ever flood.

The climate is tropical subhumid but becomes drier in the central portion of this region. As in other subtropical forests, there is a long dry season that is responsible for the deciduous nature of the forests. Precipitation levels do not reach above 1200 mm (47 in) per year.

Dominant vegetative species in the central portion of the region are: tsalam (Lysiloma bahamensis) and jabín (Piscidia piscipula), and can be accompanied by Alvaradoa amorphoides, Bursera simaruba, Cedrela mexicana, Chlorophora tinctoria, Cordia gerascanthus and Lonchocarpus rugosus in other areas. The accompanying species are Vitex gaumeri, Brosimum alicastrum, Caesalpinia gaumeri, Cedrela odorata, Ceiba pentandra and Sideroxylon fuetidissimum.

In the northern part of the ecoregion, near the coast, cacti become more abundant. Common cactus species include: Cephalocereus gaumeri, Pterocereus gaumeri and Lemaireocereus griseus. Herbaceous plants, epiphytes and fungi are rather scarce, but bromeliads like Tillandsia do grow on some trees.

The dry forests of Yucatán constitute a unique island of vegetation in the Gulf of Mexico region. They are isolated from other dry forests by the sea and by a vast extension of humid forests in the Maya region.

Some researchers hypothesize that the isolation of the dry forests has been responsible for the unique composition of the region’s flora and fauna, as well as for the specific processes governing animal and plant dispersion.

Many animals and plants cannot survive or readily disperse into the surrounding ecoregions, a fact that has accounted for the local distributions, and thus, high numbers of endemic species of this region. Plant endemism has been estimated to reach nearly 10% of the total vegetation.

The northern portion of the region, where cacti are abundant, contains 10 of the 14 endemic cacti of the Yucatán Peninsula. The region is considered among the Mexico’s richest regions in terms of its herpetofauna because it houses many endemic amphibians and reptiles.

The Yucatán dry forests are one of the very few places in Mexico where the black-beaded lizard (Heloderma horridum), one of only two venomous lizards which exist, lives. This ecoregion is home to over 290 bird species (2 endemic) and approximately 96 mammals.

Mammals include the White-nosed coatí (Nasua narica), jaguar (Pantera onca), spider monkey (Ateles geoffroyi), and southern opossum (Didelphis marsupialis). Avifauna species include Swainson’s warbler (Limnothlypis swainsonii), yellow-lored (Yucatán) parrot (Amazona albifrons), lesser yellow-headed vulture (Cathartes burrovianus), and hooded warbler (Wilsenia citriha).