Yucatán Dry Forests

The Yucatán dry forests ecoregion is located on the northwest section of the Yucatán Peninsula. The region is flat with vegetation consisting of thorn scrub and cacti. It is isolated from other dry forests by the sea and the vast moist forests of the Maya region, thus constituting 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 coralline origin. Soils are generally young and of calcareous origin with extensive drainage, rarely flooding.

The climate is tropical and subhumid but becomes drier in the central portion of this region. As in other subtropical forests, a long dry season is responsible for the deciduous nature of the forests. Precipitation levels rarely exceed 1,200 mm (47 in) per year.

Flora and Fauna

Dominant vegetative species in the central portion of the region include tamarind (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.

Accompanying species include Vitex gaumeri, Brosimum alicastrum, Caesalpinia gaumeri, Cedrela odorata, Ceiba pentandra, and Sideroxylon fuetidissimum.

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

Some researchers hypothesize that the ecoregion's isolation from other dry forests is responsible for the unique composition of flora and fauna and 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. In addition, the area is considered among 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 few places in Mexico where the black-beaded lizard (Heloderma horridum), one of only two venomous lizards, exists, lives. In addition, this ecoregion is home to over 290 bird species (two endemics) 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).

Protection Status

The Yucatán dry forests have been extensively cleared for cattle ranching and agriculture, including henequén plantations.

A very small percentage of the region is protected. Protected areas include the Ría Lagartos Biosphere Reserve, Los Petenes Biosphere Reserve, and several state reserves.

_{Map illustrating the approximate location of the Yucatán dry forests (in green)}