Elemental Composition of Utricularia‐Periphyton Ecosystems from Okefenokee Swamp

Abstract

The elemental composition (% dry mass), production (grams per square metre per year), mass (grams per square metre), and environmental variables of Utricularia-periphyton eco- systems from Okefenokee Swamp were measured each month for a year. These ecosystems were found to be most productive in the spring and fall and least productive in the summer when water levels were low. Concentrations and standing stocks of tissue ash, P, N, K, Na, Ca, Mg, Fe, Al, and Mn were correlated with various environmental parameters: temperature, dissolved 02, K, Na, Ca, Mg, pH, and water depth. Standing stocks of elements were, in general, more correlated with envi- ronmental parameters than were concentrations (% dry mass). Phase plane diagrams were used to demonstrate that elemental concentrations and production in the ecosystems followed well-defined cycles that were related to environmental fluctuations.