Response to eutrophication Dr. Steven C. Pennings University of Houston

Department of Biology and Biochemistry University of Houston Houston Texas 77204-5513 USA

scpennin@central.uh.edu https://uh.edu/nsm/biology-biochemistry/people/profiles/steven-pennings/ https://orcid.org/0000-0003-4757-7125 Georgia Coastal Ecosystems LTER Project

Dept. of Marine Sciences University of Georgia Athens Georgia 30602-3636 USA

gcelter@uga.edu https://gce-lter.marsci.uga.edu/ Dr. Steven C. Pennings University of Houston

Department of Biology and Biochemistry University of Houston Houston Texas 77204-5513 USA

scpennin@central.uh.edu https://uh.edu/nsm/biology-biochemistry/people/profiles/steven-pennings/ https://orcid.org/0000-0003-4757-7125 Principal investigator Caroline R. McFarlin University of Georgia

Dept. of Marine Sciences University of Georgia Athens Georgia 30602-3636 USA

car@uga.edu Graduate research assistant 2026

C. McFarlin (M.S. student, UGA) and S. Pennings (UH) examined spatial variation in nutrient effects on marsh community structure. The border between two dominant marsh plants, Spartina alterniflora and Juncus roemerianus, was fertilized at 19 sites within the LTER domain for two years. Across all sites there was a strong increase in biomass of live and dead S. alterniflora and a decrease in biomass of live and dead J. roemerianus in fertilized plots. Decomposer fungi on dead S. alterniflora leaves did not increase per unit of dead leaf, but did increase on a per-plot basis. Herbivorous grasshoppers increased in abundance, but detritivorous snails did not. All responses varied among sites.

Question 2: How do the spatial and temporal patterns of biogeochemical processes, primary production, community dynamics, decomposition, and disturbance vary across the estuarine landscape, and how do they relate to environmental gradients? (more information)

LTER NSF Georgia GCE Juncus Spartina community fungi grasshoppers marsh nutrients snails Overall geographic extent of the research project -81.759763 -81.119291 31.771190 30.892711 2002-01-01 2004-06-01

National Science Foundation grant numbers OCE-9982133 and OCE-0620959

estuary marsh complex Central Georgia Coast - Central Georgia coastal region from the South Newport River (northern extent) to the Satilla River (southern extent), and from the outer banks of the barrier islands (eastern extent) to approximately 35km inland (western extent) -81.759763 -81.119291 31.771190 30.892711 McFarlin, C.R., Brewer, J.S., Buck, T.L. and Pennings, S.C. 2008. Impact of fertilization on a salt marsh food web in Georgia. Estuaries and Coasts. 31:313-325. McFarlin, C.R., Buck, T.L., Newell, S.Y. and Pennings, S.C. 2003. Poster: Impact of fertilization on the abundance of two detritivorous snails. Uplands to Lowlands: Coastal Processes in a Time of Global Change. Aquatic Systems. Ecological Society of America, August 3-8, 2003, Savannah, GA. McFarlin, C.R., Buck, T.L., Newell, S.Y. and Pennings, S.C. 2003. Poster: Impact of fertilization on the abundance of two detritivorous snails. Embarking on a Decade of Synthesis. 2003 LTER All Scientists Meeting, September 18-21, 2003, Seattle, WA.