The aquatic and border vegetation are physically and biologically connected and are of ecological importance, providing complex habitats and resources for a high variety of other aquatic organisms (Rzedowski, 2006). The knowledge of the aquatic and subaquatic vegetation in Mexico is fragmentary. In particular for the Usumacinta River (the most important river of Mexico) where watershed has been only partially studied. In this study, we revised and created the knowledge available on the plant communities, the riparian and aquatic plant species along the Usumacinta River watershed, and supplemented this knowledge with data collected in the study area. The data of floristic inventory of the Usumacinta river watershed was integrated with data provided by the National System of Information on Biodiversity of the National Commission for the Knowledge and Use of the Biodiversity (SNIB-CONABIO), literature, herbaria samples of UAC, ENCB, UJAT, Ecosur-SCLC and MEXU, and field data.
We registered 212 families and 3,501 species; the families with most species were those of legumes (342), followed by orchids (295), the composite family (214), and grasses (195) (Ochoa-Gaona et al. 2018). Such numbers of plant species is a good indication of the great diversity and floristic richness of aquatic and border plants in the Usumacinta River watershed. We registered 36 families and 148 aquatic and subaquatic plant species, numbers which confirm the importance of the Usumacinta watershed for these species groups.
The borders of the Usumacinta River are threatened by human activity. The villages’ are planting ornamental and fruit trees, both native as introduced species. However, it is still possible to find original plant communities either in the lagoons, or along the Usumacinta river; for example, shrublands of muco (Dalbergia brownei or D. glabra) (Novelo and Ramos, 2005). The most common tree species registered are typical of riverine forest communities, such as: Bucida buceras (pucté), Inga vera (jinicuil), Haematoxylum campechianum (tinto), Pithecellobium lanceolatum (tucuy) and Salix humboldtiana (sauce), all of which are still present in border-forested fragments along the Usumacinta, San Pedro and Palisade rivers (Miranda and Hernández X., 1963) (Novelo and Ramos, 2005). The border vegetation near the coast is dominated by mangroves, such as Rhizophora mangle (red mangle), associated with Laguncularia racemosa (white mangle), Avicennia germinans (mangle prieto) and Conocarpus erectus (botoncillo) (Rzedowski, 2006).
We registered five species which had value and/or use: Annona glabra (anona) which is edible, Crescentia cujete (jícaro) which is ornamental, Guatteria anomala (palo of zope) which is used as food of turtles and parakeets, Sagittaria lancifolia (tule) like handmade and screws, and Vallisneria americana (sargazo) which is also known to be in the diet of turtles. This work highlights the importance of the riverine and aquatic vegetation for human communities, besides the service of food, nesting sites, refuge and rest for the regional fauna.
This diversity of plants is integrated in plant communities which stabilizes the silt, oxygenates the water, provides refuge and material for nest sites, are habitats for different species of fauna, and provides multiple ecosystem services which depend partly on the population that lives in the region (Mendoza-Carranza et al. 2010). The villagers depend on the hydrological functions because fishing is an important source of economic income, and a local food source. Many of people that live in the watershed recognize the importance of the plants as a source of food for the aquatic fauna. As such, the management and conservation of the wetlands is of great importance.
Literature
Lot, A., Olvera, M., Flores, C. and Díaz, A. (2015). Guía ilustrada de campo. Plantas indicadoras de humedales. Instituto de Biología, Universidad Nacional Autónoma de México. México D.F., México.
Mendoza-Carranza, M., Hoeinghaus, D. J., Garcia, A. M. and Romero-Rodriguez, A. (2010). Aquatic food webs in mangrove and seagrass habitats of Centla Wetland, a Biosphere Reserve in Southeastern Mexico. Neotropical Ichthyology 8, 171-178.
Miranda, F. and Hernández-X E. (1963). Los tipos de vegetación de México y su clasificación. Boletín de la Sociedad Botánica de México, 28, 29-162
Novelo, A. and Ramos, L. (2005). Vegetación acuática. En: J. Bueno, F. Álvarez y S. Santiago (Eds.), Biodiversidad del estado de Tabasco, (pp. 111-143). México, D.F.: Instituto de Biología, UNAM-CONABIO.
Ochoa-Gaona, S., L.J. Ramos Ventura, F. Moreno Sandoval, N. del C. Jiménez Pérez, M.A. Haas Ek, and L.E. Muñiz Delgado. 2018. Diversidad de flora acuática y ribereña en la cuenca del rio Usumacinta. Revista Mexicana de Biodiversidad 89 (Suplem. 2018): S3 - S44. ISSN versión electrónica: 2007-8706 http://dx.doi.org/10.22201/ib.20078706e.2018.0.2395
Rzedowski, J. (2006). Vegetación de México. 1ra. Edición digital. México. Comisión Nacional para el Conocimiento y Uso de la Biodiversidad. Recuperado el 04 noviembre, 2016 de: http://www.biodiversidad.gob.mx/publicaciones/librosDig/pdf/VegetacionMx_Cont.pdf