Biodiversidad de la selva baja caducifolia en un sustrato rocoso de origen volcánico en el centro del Estado de Veracruz, México
The study site is characterized by a rocky terrain of volcanic origin that resulted from a deposition of volcanic lava that occurred 10,000 years ago in the water catchments of the Rio Actopan found in the center of the state of Veracruz, Mexico. The area is located between latitude19º 31´ and 19º 3...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2003 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:1j92g7979 |
| Acceso en línea: | https://doi.org/10.24275/uami.1j92g7979 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Biodiversity -- Veracruz info:eu-repo/classification/LEM/Selvas -- Veracruz info:eu-repo/classification/LEM/Jungles -- Veracruz info:eu-repo/classification/LEM/Biodiversidad -- Veracruz info:eu-repo/classification/cti/3 |
| Sumario: | The study site is characterized by a rocky terrain of volcanic origin that resulted from a deposition of volcanic lava that occurred 10,000 years ago in the water catchments of the Rio Actopan found in the center of the state of Veracruz, Mexico. The area is located between latitude19º 31´ and 19º 37´ north, and 96º 41´ and 96º 54´ longitude west. The rocky landscape was divided in different units according to physical, biological, and land use characteristics. The characteristics that stand out are basalt lava, the crater of the monogenetic cineritic type, the steep slopes, the fluvial plains formed by the superficial rivers, the hills and a tilted plain. The objective of this research was to establish the alpha and gamma plant diversity, as well as the species turnover (beta diversity) among the low-stature deciduous forest and the secondary vegetation, in relation to the altitudinal gradient. The endemic plants were also identified, as well as the succulent flora found in the study site. For these, at each 100 m altitude, transects of 0.5 to 2.5 km long were established, transversal to the study site. Information was taken at 100 m2 quadrats for the arboreal and shrubby strata, and 4 m2 for the herbaceous one, at distances of 50 m each. At each quadrat herbarium specimens of the vascular plants were recorded and collected. Besides species cover, different environmental parameters were taken, such as slope, rockiness, altitude and mineral soil. Results show that the low-stature deciduous forest and secondary vegetation found at this volcanic terrain are highly rich species, having recorded 683 species, 395 genera, and 103 families of vascular plants. A high turnover of species was also found throughout the landscape. Also, the impact of human activity was found to be high, since about 70% of the original vegetation had been substituted by secondary vegetation. The latter was found to have caused a loss of species of the original vegetation that can barely colonize again the existent secondary habitats. Among the groups of families and species that were found to be more affected are pteridophytes, orchids, cacti, and bromeliads, which show certain specificity for these types of habitats. Also, most of the succulent flora, endemic species and woody plants native to primary forests that have also been affected. Diversity type of lowstature deciduous forest was found to be more then 50% registered for this type of vegetation in other areas of the center of central Veracruz. This rocky terrain is considered to concentrate the greatest percentage of endemic species per unit area for the region. |
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