Southern North America: Eastern Mexico

The mangroves of Quintana Roo are part of a coastal formation that also includes estuaries, coastal dunes, and coral reefs coexisting in the same area (SEMARNAP 1996). This increases the overall biodiversity of the area and elevates the complexity of interactions among different environments, which in turn raises the region's value for biological conservation. They constitute the most extensive habitat for crocodiles in Mexico, and support one of the best preserved populations of Crocodilus moreletti (CONABIO-INE 1995). The area also supports several other endangered species, many of which use the mangroves as a feeding area although their primary habitats are the dry forests of Quintana Roo.

  • Scientific Code
  • Ecoregion Category
  • Size
    1,600 square miles
  • Status
    Relatively Stable/Intact
  • Habitats

Location and General Description
This ecoregion lies on a vast plateau located on the Atlantic coast of the Mexican state of Quintana Roo. Soils are shallow and rocky and derive from sedimentary rocks, primarily limestone. When limestone suffers weathering, it hardens and forms surface plates known as lajas. The climate is tropical subhumid with summer rains; precipitation levels are high (1300 mm/year). The location of these mangroves on the Yucatan Peninsula makes them very susceptible to hurricanes; in the last 88 years, the region received 11 hurricanes (SEMARNAP 1996).

Two different types of mangroves grow in Quintana Roo. The smaller, appropriately called "pygmy mangroves", are composed of trees no taller than 2 m. The fringe mangrove on the other hand, grows on the edge of coastal lagoons, and sometimes reach 12 m in height. The dominant species in both types are: Rhizophora mangle, Laguncularia racemosa, Avicennia germinans and Conocarpus erectus. The pygmy mangrove also includes Cladium jamaicensis and Elaocharis cellulosa. As in most mangroves, herbaceous vegetation is not abundant in these communities, because it is intolerant of permanent floods (Janzen 1985; Lot et al. 1993).

Biodiversity Features
There are 96 species of mammals in the area, and 322 species of birds, approximately two thirds of which nest in the ecoregion. In addition, 21 of 23 species of the order Ciconiiformes of Mexico inhabit these mangroves (López-Ornat 1992). The mangroves are the second most important place in Mexico for endangered birds such as Jabiru, wood stork, and white ibis and are the most important site for the reproduction of the great white heron. They also receive a number of flamingos during the winter. CONABIO has identified a terrestrial priority site within this ecoregion: Sian Ka’an-Uaymil-Xcalak (Arriaga et al. 2000). There are also two important bird area’s here: Sian Ka’an and U yumil C'eh, A.C. (Benitez et al. 1999).

Mammals found in the mangroves of this ecoregion include jaguar (Panthera onca), puma (Felis concolor), ocelot (Leopardus pardalis), manatee (Trichecus manatus). Birds are the most numerous fauna in the ecoregion with lesser yellow-headed vulture (Cathartes burrovianus), ocellated turkey (Agriocharis ocellata), white-crowned pigeon (Columba leucocephala), black catbird (Melanoptila glabrirostris), reddish egret (Egretta rufescens), anhinga (Anhinga anhinga), clapper rail (Rallus longirostris) cormarant (Phalacrocorax spp.), roseate spoonbill (Ajaia ajaja), greater flamingo (Phoenicopterus ruber), and jabiru (Jabiru mycteria) listed as a sampling. Reptiles are represented by green turtle (Chelonia Mydas), hawksbill turtle (Eretmochelys imbricata), loggerhead turtle (Caretta caretta), leatherback turtle (Dermochelys coriacea), Morelet's crocodile (Crocodylus moreletii), and American crocodile (C. acutus).

Current Status
Together with the coral reefs, the mangroves constitute the only intact habitat in Quintana Roo. The state is recognized for the low degree of disturbance to native vegetation (Flores-Villela & Gerez 1994). 68% of the state has suffered from some degree of disturbance, but the rest is intact, which explains the well-preserved state of ecosystems in the ecoregion.

The Biosphere Reserve of Sian Ka’an protects a vast area of coastal formations, mangroves, and some patches of dry forests. The reserve is well preserved because it lacks roads making access to the area difficult.

Types and Severity of Threats
It is highly probable, however that mangrove tourism will increase in the next few years, which could cause significant disturbances to native vegetation if appropriate measures are not taken. Exotic species of plants (e.g. Casuarina) have been introduced directly in the coastal ecosystems, without knowledge of the potential effects of these plants on the native flora. In fact, the so-called pine tree (Casuarina) is responsible for displacing plant species that have a specific function as soil retention, including mangrove trees (Rzedowski 1988; Tomlinson 1994). Moreover, soils in this area are rocky, lowering their potential as cultivable lands, and the abundance of flooded lands deters logging activities. One of the main threats to the area is intensive exploitation of wildlife: native villagers have hunted the manatee in high numbers, and extract iguanas, and turtles and other reptiles to sell as food. In general, better law enforcement is needed to control the illegal wildlife trade.

Justification of Ecoregion Delineation
Classification and linework for all mangrove ecoregions in Latin America and the Caribbean follow the results of a mangrove ecoregion workshop (1994) and subsequent report (Olson et al. 1996).

Arriaga, L., J.M. Espinoza, C. Aguilar, E. Martínez, L. Gómez y E. Loa (coordinadores). 2000. Regiones terrestres prioritarias de México. Escala de trabajo 1:1 000 000. Comisión Nacional para el Conocimiento y uso de la Biodiversidad. México.

Benitez, H., C. Arizmendi y L. Marquez. 1999. Base de datos de las AICAS. CIPAMEX, CONABIO, FMCN y CCA. Mexico.

CONABIO & INE. 1995. Reservas de la Biósfera y otras áreas naturales protegidas de México. SEMARNAP, México. 159 pp.

Ecoregional Workshop: A Conservation Assessment of Mangrove Ecoregions of Latin America and the Caribbean. 1994. Washington D.C., World Wildlife Fund.

Flores-Villela, O. 1993. Herpetofauna de México: distribución y endemismo. In: Ramamoorthy, T.P., Bye, R., Lot, A. andFa, J. (Eds). Diversidad Biológica de México. Orígenes y Distribución. Instituto de Biología, UNAM. pp. 251-278

Janzen, D.H. 1985. Mangroves: Where's the understory? Journal of Tropical Ecology Vol. 1: 89-92

López-Ornat, A. 1992. Avifauna de la Reserva de la Biósfera de Sian Ka’an. In: Navarro, D. and Robinson, J.G. (Eds). Diversidad Biológica en la Reserva de la Biósfera de Sian Ka’an, Q.Roo, México. CIQRO, México. Pp. 331-370.

Lot, A., Novelo, A., and Ramírez-García, P. 1993. Diversidad de la flora acuática mexicana. In: Ramamoorthy, T.P., Bye, R., Lot, A., & Fa, J. (eds). Diversidad Biológica de México. Orígenes y Distribución. Instituto de Biología, UNAM. Pp. 563-578.

Olson, D.M., E. Dinerstein, G. Cintrón, and P. Iolster. 1996. A conservation assessment of mangrove ecosystems of Latin America and the Caribbean. Final report for The Ford Foundation. World Wildlife Fund, Washington, D.C.

Rzedowski, J. 1988. Vegetación de México. Editorial Limusa, México. 431 pp.

SEMARNAP. 1996. Programa de Manejo de la Reserva de la Biósfera de Sian Ka’an, Quintana Roo, México. SEMARNAP, D.F. México.

Tomlinson, P.B. 1994. The Botany of Mangroves. Cambridge University Press. Pp. 166-168.

World Conservation Monitoring Center, Protected Areas Programme. Data sheet for the Sian Ka'an Biosphere Reserve:'a.html

Prepared by: Alejandra Valero
Reviewed by: In process