Nutrient effects on seagrass epiphyte community structure in Florida Bay

Authors

Thomas A. Frankovich, Department of Biological Sciences and Southeast Environmental Research Center, Florida International UniversityFollow
Anna R. Armitage, Department of Marine Biology, Texas A&M UniversityFollow
Anna Honorata Wachnicka, Department of Earth Sciences and Southeast Environmental Research Center, Florida International UniversityFollow
Evelyn E. Gaiser, Department of Biological Sciences and Southeast Environmental Research Center, Florida International UniversityFollow
James W. Fourqurean, Department of Biological Sciences and Southeast Environmental Research Center, Florida International UniversityFollow

Abstract

A field experiment was employed in Florida Bay investigating the response of seagrass epiphyte communities to nitrogen (N) and phosphorus (P) additions. While most of the variability in epiphyte community structure was related to uncontrolled temporal and spatial environmental heterogeneity, P additions increased the relative abundance of the red algae–cyanobacterial complex and green algae, with a concomitant decrease in diatoms. When N was added along with P, the observed changes to the diatoms and the red algae–cyanobacterial complex were in the same direction as P-only treatments, but the responses were decreased in magnitude. Within the diatom community, species relative abundances, species richness, and diversity responded weakly to nutrient addition. P additions produced changes in diatom community structure that were limited to summer and were stronger in eastern Florida Bay than in the western bay. These changes were consistent with well-established temporal and spatial patterns of P limitation. Despite the significant change in community structure resulting from P addition, diatom communities from the same site and time, regardless of nutrient treatment, remained more similar to one another than to the diatom communities subject to identical nutrient treatments from different sites and times. Overall, epiphyte communities exhibited responses to P addition that were most evident at the division level.

Comments

This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements #DBI-0620409 and #DEB-9910514. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Recommended Citation

Frankovich, T.A., A.R. Armitage, A. Wachnicka, E.E. Gaiser, J.W. Fourqurean. 2009. Nutrient effects on seagrass epiphyte community structure in Florida Bay. Journal of Phycology 45: 1010-1020.