Veracruz moist forests
|
|
The Veracruz moist forests is an ecoregion widely acknowledged as a place of great importance for many plant and animal species. Covering the area from the Sierra Madres Oriental westward to the coast of the Gulf of Mexico, this ecoregion is considered both a center of plant endemism and is held within two separate endemic bird areas. It is also the most northern occurrence of subhumid tropical forest in Mexico, although very little remains and what remains needs protection, as well as the wildlife that relies on this habitat.
Contents
Location and General Description
This moist forest ecoregion is situated on the Gulf of Mexico’s northeastern coastal plain of Mexico, in the north of Veracruz and the south of Tamaulipas states. The ecoregion encompasses lowlands of the eastern slopes of the Sierra Madre Oriental.
It is composed of sedimentary rocks from the cretaceous period, and the abundance of this material is responsible for the karstic topography of the ecoregion. The resulting soils are shallow but rich in organic matter.
The climate is tropical humid, with rains during seven months of the year with mild temperature oscillations. The precipitation levels range between 1100 and 1600 millimeters (mm) each year.
Although many authors regard this ecoregion as an area of pristine and undisturbed moist forests, the most recent studies demonstrate that only small areas of intact moist forests remain. These remnants are restricted to small areas where steep terrain offers protection. However, the few areas that still contain moist forest assemblages also termed "Tropical Evergreen Forest" are characterized by tall trees reaching up to 30 meters (m), where the dominant species are: Mayan breadnut (Brosimum alicastrum), sapodilla (Manilkara zapota), rosadillo (Celtis monoica), Bursera simaruba, Dendropanax arboreus, and Sideroxylon capiri. In central Veracruz State, in the southern portion of this ecoregion, the forest’s vegetative association changes and the dominant species become mahogany (Swietenia macrophylla), sapodilla (Manilkara zapota), Bernoullia flammea, and Astronium graveolens. In the state of San Luis Potosí, the trees are even taller than in Tamaulipas, although with the same dominant species in the canopy (e.g. Brosimum alicastrum and Celtis monoica). The herbaceous stratum is very well developed, and epiphytes are abundant as well as lichens and fungi.
Biodiversity Features
The moist forests of Veracruz ecoregion constitute the northernmost portions of moist forest and associated subhumid tropical vegetation distributed in Mexico. Veracruz has been described as one of the richest faunistic regions in the west hemisphere, and is one of three regions with the highest insect richness and endemism. Birdlife International has included this area in its Endemic Bird Area (EBA) project, due to the rich endemic avifauna of the region. Endemic birds include the green-cheeked amazon (Amazona viridigenalis), Tamaulipas crow (Corvus imparatus), Altamira yellowthroat (Geothlypis flavovelata) and crimson-collared grosbeak (Rhodothraupis celaeno). These montane forests have special significance because of their high biodiversity and use as a flyway for migratory birds; however, their degree of deterioration is so high that the forest is now composed of small fragments of vegetation.
Many endangered mammals inhabit these forests, as well as endangered birds. There are also two endemic rodents (Peromyscus ochraventer, Neotoma angustapalata). They are located in and around the area designated as a centre of plant diversity called the Gomez Farias Region and El Cielo Biosphere Reserve, which falls within this ecoregion. Jaguar (Pantera onca), ocelot (Leopardus pardalis), jaguarundi (Herpailurus yaguarondi) and coati (Nasua narica) are some unique yet locally or widely threatened mammal species of this ecoregion.
Current Status
Large portions of this forest have already been eliminated. At present, very little of the actual vegetation corresponds to the original plant associations and the forests of Veracruz have become restricted to a series of patches scattered north to south from Tamaulipas to central Veracruz. The forests have been almost completely destroyed and substituted by scrub and secondary communities. Vast portions of the forests have been extensively logged, resulting in the loss of habitat and biodiversity. From 1900 to 1987, over 18,553 kilometers2(km2) of forest in the state of Veracruz were logged. Trees are cut down for use in the timber industry. Also, valuable wood is overexploited, but since these species are not abundant, vast portions of forest are logged in search of sufficient quantities of this precious timber. Large areas of forest have also been removed the local subsistence farmers as they introduce cattle. Cattle grazing is one of the main factors involved in the destruction of these. Veracruz is one of the primary cattle farming entities of Mexico. Moist forests of Veracruz once occupied most of the state, but now they represent the most transformed ecological zone in the region. Approximately 64% of the state of Veracruz is subjected to human exploitation, and only 20% of the natural vegetation is intact, with 14% representing secondary communities. Despite the importance of the region as a remnant of humid forest, El Cielo Biosphere Reserve in southern Tamaulipas is the only protected area that has been established.
Types and Severity of Threats
Remaining species and [[habitat]s] are threatened by human activities and the resulting associated problems. Continued clearing of forest for timber, road construction, expansion of settlements, free roaming cattle, collection of fuelwood, orchids and animals by local people, industrial development and agricultural expansion. These threats bring consequences with them such as water pollutionfrom wastes, clearing of land and alteration of vegetative structure due to gathering of more valuable plants, which are all associated with the expansion of human settlements. Ecotourism is increasing but while economic growth is beneficial to the ecoregion, dealing with more people will call for the improvement of health related systems. El Cielo Biosphere Reserve is also threatened even as the only protected area in the ecoregion; it lacks funding. Timber companies are seeking permits to log the buffer zone. Cattle enter the forests to graze and people illegally gather plants and hunt animals for their personal subsistence and to sell. The condition of this reserve will continue to deteriorate until budgets are increased.
Justification of Ecoregion Delineation
The delineations for this ecoregion were derived from the INEGI current landcover maps, from which we're lumping montane mesophyll forests classifications with human modified landscapes along the eastern flank of the Sierra Madre Oriental. Linework was then modified by experts at several ecoregion workshops. This ecoregion represents the most northerly of the montane moist forests, and are a convergence zone for temperate and tropical flora and fauna – yet remains the northernmost extension of tropical broadleaf montane moist forests in the Americas, and with several endemic species.
Further Reading
- For a terser summary of this entry, see the WWF WildWorld profile of this ecoregion.
- Bibby, C.J., N.J.Collar , M.J. Crosby, M.F. Heath, Ch. Imboden Crosby, T.H. Johnson, A.J. Long, A.J. Stattersfield, and S.J. Thirgood 1992. Putting biodiversity on the map: Priority Areas for Global Conservation. International Council for Bird Preservation, Cambridge, U.K.
- Barrera-Bassols, N., C.López, and R. Palma, 1993. Vacas, pastos y bosques en Veracruz: 1950-1990. Barrera, N. and H. Rodríguez, editors. Desarrollo y medio ambiente en Veracruz. Fundación Friedrich Ebert. México, D.F.
- Boege, E. and H. Rodríguez, 1992. Desarrollo y Medio Ambiente en Veracruz. Fundación Friedrich Ebert. Stiftung. Instituto de Ecología, A.C. Xalapa, México.
- Challenger, A. 1998. Utilización y conservación de los ecosistemas terrestres de México. Pasado, presente y futuro. Conabio, IBUNAM y Agrupación Sierra Madre, México.
- CONABIO Workshop, 17-16 September, 1996. Informe de Resultados del Taller de Ecoregionalización para la Conservación de México.
- CONABIO Workshop, Mexico, D.F., November 1997. Ecological and Biogeographical Regionalization of Mexico..
- Davis, S.D., V.H. Heywood, O. Herrera MacBryde, J. Villa-Lobos and A.C. Hamilton, editors. 1997. Centres of Plant Diversity. A Guide and Strategy for their Conservation. Volume 3. The Americas. IUCN Publications Unit, Cambridge, U.K. 562 pp.
- INEGI Map. 1996. Comision Nacional Para el Conocimiento y Uso de la Biodiversidad (CONABIO) habitat and land use classification database derived from ground truthed remote sensing data Insitituto Nacional de Estastica, Geografia, e Informática (INEGI). Map at a scale of 1:1,000,000.
- Martin, P.S. 1958. Biogeography of reptiles and amphibians in the Gomez Farías region., Tamaulipas, México. Museum of Zoology. University of Michigan. Misc. Publ. 101: 1-102.
- Ordoñez, M.J. and F.García-Oliva, 1992. Zonificación ecoproductiva de Veracruz. E. Boege and H. Rodriguez, editors. Desarrollo y Medio Ambiente en Veracruz. Fundación Friedrich Ebert. Stiftung. Instituto de Ecología, A.C. Xalapa, México. Pages 31-49 in Robles-Gil, P., G. Ceballos and F. Eccardi, 1993. Mexican diversity of fauna. Cemex & Sierra Madre, México.
- Rzedowski, J. 1978. Vegetación de Mexico. Editorial Limusa. Mexico, D.F., Mexico.
- Rzedowski, J. pers.comm. at CONABIO Workshop, 17-16 September, 1996. Informe de Resultados del Taller de Ecoregionalización para la Conservación de México
- Stattersfield, A.J., M.J. Crosby, A.J. Long and D.C. Wege. 1998. Endemic Bird Areas of the World: Priorities for Biodiversity Conservation. Birdlife Conservation. Series No. 7., Birdlife International, Cambridge, UK.
- Toledo, V.M and M.J.Ordoñez. 1993. El panorama de la biodiversidad en México: una revisión de los habitats terrestres. Pages 739-758 in T.P. Ramamoorthy, R. Bye, A. Lot, and J. Fa, editors. Diversidad Biológica de México. Orígenes y distribución. Instituto de Biología, UNAM.
- Toledo, V.M., J. Carabias, C., Toledo, and C. González-Pacheco. 1989. La producción rural en México: alternativas ecológicas. Colección Medio Ambiente, No. 6. Fundación Universo Veintiuno, México.
- Valiente-Banuet, A., F. González-Medrano, and D. Piñero-Dalmau, 1995. La vegetación selvática de la region de Gómez Farías, Tamaulipas, México. Acta Botánica Mexicana 33: 1-36.
| Disclaimer: This article contains information that was originally published by the World Wildlife Fund. Topic editors and authors for the Encyclopedia of Earth have edited its content and added new information. The use of information from the World Wildlife Fund should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content. |
