Variable nutrient stoichiometry (carbon:nitrogen:phosphorus) across trophic levels determines community and ecosystem properties in an oligotrophic mangrove system

• Published in: Oecologia Vol. 179; no. 3; pp. 863 - 876
• Main Authors: Scharler, U. M, Ulanowicz, R. E, Fogel, M. L, Wooller, M. J, Jacobson-Meyers, M. E, Lovelock, C. E, Feller, I. C, Frischer, M, Lee, R, McKee, K, Romero, I. C, Schmit, J. P, Shearer, C
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.11.2015; Springer; Springer Nature B.V
• Subjects: Animals; Belize; Biomass; Biomedical and Life Sciences; Carbon - analysis; Carbon - metabolism; Detritus; Ecology; Ecosystem; Ecosystem components; ECOSYSTEM ECOLOGY; Ecosystem ecology - Original research; Ecosystem studies; Ecosystems; Food Chain; Food webs; heterotrophs; Hydrology/Water Resources; invertebrates; Invertebrates - physiology; Leaf litter; Life Sciences; mangrove forests; Nitrogen; Nitrogen - analysis; Nitrogen - metabolism; Nutrients; Phosphorus - analysis; Phosphorus - metabolism; plant litter; Plant Sciences; Recycling; Recycling industry; Reefs; stoichiometry; trees; Trees - physiology; Trophic levels; Wetlands; Belize; ASW, Belize, Stann Creek Dist., Twin Cays; ASW, Belize; Mangrove food web; Transfer efficiency; Recycling; Nutrient limitation; Oligotrophic environment
• ISSN: 0029-8549; 1432-1939
• DOI: 10.1007/s00442-015-3379-2

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.