1. Unique Nutrient Sources
FCE scientists discovered that, unlike in most coastal areas, the natural source of
phosphorus (the nutrient that limits ecosystem productivity) for coastal Caribbean estuaries
is seawater, not inland environments. This important finding has ramifications for both
restoration and conservation and is informing decision making in coastal areas.
FCE research has shown that the Everglades operates differently from other coastal
ecosystems in that its estuaries that are "upside-down," with seawater supplying limiting
nutrients landward, rather than the other way around. Collaborative research with Caribbean
scientists, particularly those associated with Mexican LTER programs (MexLTER), has shown
similar upside-down features in similar tropical low nutrient wetlands of the Yucatan
peninsula and northern Belize. Because this finding has ramifications for coastal
restoration and conservation, FCE scientists are continuing collaborations with Mexican
colleagues to establish coordinated science and education programs to improve adaptive
decision-making in coastal ecosystems of south Florida, the Yucatan, and throughout the
These two FCE research sites show the unexpected 'wedge of productivity' of mangrove forests in the Everglades. Marine sources of phosphorus enable mangrove forest canopy to reach 20m or more, as is seen in the image on the right, compared to the mangroves on the left that are growing several miles inland.
Credit: Robert Twilley (image on the left) and Stephen Davis (image on the right)
Long-term data showing soil elevation (solid line, right axis), estuary water total phosphorus (TP) concentration (dashed line, right axis), and mangrove forest Net Ecosystem Production (NEP, shaded area, left axis) before and after Hurricane Wilma (October 2005). The hurricane defoliated the mangrove forest and associated storm surge deposited 4 cm of P-enriched mud from the Gulf of Mexico that left a legacy in the water column by slowly leaching back out into the estuary.
Source: Evelyn Gaiser
For further reading:
Barr, J.G., V. Engel, J.D. Fuentes, J.C. Zieman, T.L. O'Halloran, T.J. Smith, G. Anderson. 2010. Controls on mangrove forest-atmosphere carbon dioxide exchanges in western Everglades National Park. Journal of Geophysical Research 115: G02020. DOI: 10.1029/2009JG001186
Castañeda-Moya, E., R.R. Twilley, V.H. Rivera-Monroy, K. Zhang, S.E. Davis, M.S. Ross. 2010. Sediment and Nutrient Deposition Associated with Hurricane Wilma in Mangroves of the Florida Coastal Everglades. Estuaries and Coasts 33(1): 45-58. DOI: 10.1007/s12237-009-9242-0
Childers, D.L., J.N. Boyer, S.E. Davis, C.J. Madden, D.T. Rudnick, F.H. Sklar. 2006. Relating precipitation and water management to nutrient concentration patterns in the oligotrophic "upside down" estuaries of the Florida Everglades. Limnology and Oceanography 51: 602-616.
Price, R.M., P.K. Swart, and J.W. Fourqurean. 2006. Coastal groundwater discharge - an additional source of phosphorus for the oligotrophic wetlands of the Everglades. Hydrobiologia 569: 23-36.
Rivera-Monroy, V.H., R.R. Twilley, D. Bone, D.L. Childers, C. Coronado-Molina, I.C. Feller, J.A. Herrerra-Silviera, R. Jaffe, J.E. Mancera, E. Rejmankova, J.E. Salisbury. 2004. A conceptual framework to develop long-term ecological research and management objectives in the wider Caribbean Region. BioScience 54: 843-856.
For further information: