Co-ordinating Editor: Sara Cousins
Oceanographic anomalies and sea-level rise drive mangroves inland in the Pacific coast of Mexico
Article first published online: 12 JAN 2011
© 2011 International Association for Vegetation Science
Journal of Vegetation Science
Volume 22, Issue 1, pages 143–151, February 2011
How to Cite
López-Medellín, X., Ezcurra, E., González-Abraham, C., Hak, J., Santiago, L. S. and Sickman, J. O. (2011), Oceanographic anomalies and sea-level rise drive mangroves inland in the Pacific coast of Mexico. Journal of Vegetation Science, 22: 143–151. doi: 10.1111/j.1654-1103.2010.01232.x
López-Medellín, X. (corresponding author, email@example.com): Centro de Investigaciones en Ecosistemas, Universidad Nacional Autónoma de México (CIECO-UNAM), Morelia, Michoacán 58190, Mexico Ezcurra, E. (firstname.lastname@example.org) & Santiago L.S. (email@example.com): Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA González-Abraham, C. (firstname.lastname@example.org): San Diego Natural History Museum, San Diego, CA 92101, USA Hak, J. (email@example.com): NatureServe, Boulder, CO 80303, USA Sickman, J.O. (firstname.lastname@example.org): Department of Environmental Sciences, University of California, Riverside, CA 92521, USA
- Issue published online: 12 JAN 2011
- Article first published online: 12 JAN 2011
- Received 20 September 2010, Accepted 25 October 2010
- Bahia Magdalena;
- Baja California;
- Coastal lagoons;
- Coastal vegetation change;
- El Niño;
- Sea-level rise
Question: Although mangrove forests are generally regarded as highly threatened, some studies have shown that mangrove canopies in the Pacific coast of Mexico have been increasing in recent decades. We investigated the possible causes driving this reported mangrove expansion.
Location: The mangrove lagoons of Magdalena Bay in Baja California, Mexico.
Methods: We used 50-year-old aerial photographs and 24-year-old satellite images to compare long-term vegetation change, surveyed a coastal vegetation transect to analyse flooding levels, compiled six decades of tidal and oceanographic information, as well as hurricane data to analyse changes in storm frequency or sea-level conditions, and used isotopic analysis to date the age of trees along the gradient.
Results: A significant increase in mangrove cover has occurred in backwaters of the lagoons during the last 40 years, and especially during the El Niño anomalies of the 1980s and 1990s, while at the same time the mangrove fringe has been receding.
Conclusions: The observed change can be attributed to the combined action of the warm surface waters of El Niño events and sea-level rise. Jointly, these two effects are sufficient to flood large areas of previously non-flooded salt flats, dispersing mangrove seedlings inland. The inland expansion of mangroves, however, does not ease conservation concerns, as it is the seaward fringes, and not the inland margins, that provide the most valuable environmental services for fisheries and coastal protection.