title: Variable nutrient stoichiometry (carbon:nitrogen:phosphorus) across trophic levels determines community and ecosystem properties in an oligotrophic mangrove system.
abstract: Our study investigated the carbon:nitrogen:phosphorus (C:N:P) stoichiometry of mangrove island of the Mesoamerican Barrier Reef (Twin Cays, Belize). The C:N:P of abiotic and biotic components of this oligotrophic ecosystem was measured and served to build networks of nutrient flows for three distinct mangrove forest zones (tall seaward fringing forest, inland dwarf forests and a transitional zone). Between forest zones, the stoichiometry of primary producers, heterotrophs and abiotic components did not change significantly, but there was a significant difference in C:N:P, and C, N, and P biomass, between the functional groups mangrove trees, other primary producers, heterotrophs, and abiotic components. C:N:P decreased with increasing trophic level. Nutrient recycling in the food webs was highest for P, and high transfer efficiencies between trophic levels of P and N also indicated an overall shortage of these nutrients when compared to C. Heterotrophs were sometimes, but not always, limited by the same nutrient as the primary producers. Mangrove trees and the primary tree consumers were P limited, whereas the invertebrates consuming leaf litter and detritus were N limited. Most compartments were limited by P or N (not by C), and the relative depletion rate of food sources was fastest for P. P transfers thus constituted a bottleneck of nutrient transfer on Twin Cays. This is the first comprehensive ecosystem study of nutrient transfers in a mangrove ecosystem, illustrating some mechanisms (e.g. recycling rates, transfer efficiencies) which oligotrophic systems use in order to build up biomass and food webs spanning various trophic levels.
authors.affiliation: School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4001, South Africa. scharler@ukzn.ac.za.
authors.forename: U M
authors.initials: UM
authors.lastname: Scharler
authors.affiliation: Arthur R. Marshall Laboratory, Department of Biology, University of Florida, Gainesville, FL, 32611-8525, USA.|Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, MD, 20688-0038, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Ulanowicz
authors.affiliation: Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington, DC, 20015, USA.|School of Natural Science, University of California at Merced, Merced, CA, 95343, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Fogel
authors.affiliation: School of Fisheries and Ocean Sciences, Institute of Marine Science, University of Alaska Fairbanks, Fairbanks, AK, 99775-5860, USA.|Alaska Stable Isotope Facility, Water and Environmental Research Center, University of Alaska Fairbanks, P.O. Box 755860, Fairbanks, AK, 99775-5860, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Wooller
authors.affiliation: University of Southern California Dana and David Dornsife College of Letters, Arts and Sciences, 3616 Trousdale Parkway AHF 139, Los Angeles, CA, 90089-0371, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Jacobson-Meyers
authors.affiliation: School of Biological Sciences, The University of Queensland, St Lucia, QLD, 4072, Australia.
authors.forename: C E
authors.initials: CE
authors.lastname: Lovelock
authors.affiliation: Smithsonian Environmental Research Center, Edgewater, MD, 21037, USA.
authors.forename: I C
authors.initials: IC
authors.lastname: Feller
authors.affiliation: Skidaway Institute of Oceanography, Savannah, GA, 31411, USA.
authors.forename: M
authors.initials: M
authors.lastname: Frischer
authors.affiliation: Center for Dark Energy Biosphere Investigations, University of Southern California, AHF 209, Los Angeles, CA, 90089-0371, USA.
authors.forename: R
authors.initials: R
authors.lastname: Lee
authors.affiliation: US Geological Survey, National Wetlands Research Center, Lafayette, LA, 70506, USA.
authors.forename: K
authors.initials: K
authors.lastname: McKee
authors.affiliation: College of Marine Science, University of South Florida, St Petersburg, FL, 33701, USA.
authors.forename: I C
authors.initials: IC
authors.lastname: Romero
authors.affiliation: National Capital Region Inventory and Monitoring Network, National Park Service, 4598 MacArthur Boulevard NW, Washington, DC, 20007, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Schmit
authors.affiliation: Department of Plant Biology, University of Illinois at Urbana-Champaign, Room 265 Morrill Hall, 505 South Goodwin Avenue, Urbana, IL, 61801, USA.
authors.forename: C
authors.initials: C
authors.lastname: Shearer
mesh_terms: D000818:Animals; D001531:Belize; D018533:Biomass; D002244:Carbon / Q000032:analysis / Q000378:metabolism*; D017753:Ecosystem; D020387:Food Chain; D007448:Invertebrates / Q000502:physiology; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism*; D010758:Phosphorus / Q000032:analysis / Q000378:metabolism*; D014197:Trees / Q000502:physiology; D053833:Wetlands
chemical_list: D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen
keywords: Mangrove food web; Nutrient limitation; Oligotrophic environment; Recycling; Transfer efficiency