Variation in soil phosphorus, sulfur, and iron pools among south Florida wetlands
To determine relationships between soil nutrient status and known gradients in primary production, we collected and analyzed soils from 17 LTER sampling sites along two transects through south Florida wetland ecosystems. Through upstream freshwater marsh, a middle reach including the oligohaline marsh/mangrove ecotone, and downstream estuarine habitats, we observed systematic variation in soil bulk density, organic content, and pools of phosphorus (P), inorganic sulfur, and extractable iron. Consistent with observed differences in wetland productivity known to be limited by P availability, total P averaged ~200 μg g dw−1 in soils from the eastern Taylor Slough/Panhandle and was on average three times higher in soils from the western Shark River Slough. Along both transects, the largest pool of phosphorus was the inorganic, carbonate-bound fraction, comprising 35–44% of total P. Greater than 90% of the total inorganic sulfur pool in these south Florida wetland soils was extracted as pyrite. Freshwater marsh sites typically were lower in pyrite sulfur (0.2–0.8 mg g dw−1) relative to marsh/mangrove ecotone and downstream estuary sites (0.5–2.9 mg g dw−1). Extractable iron in freshwater marsh soils was significantly higher from the Taylor Slough/Panhandle transect (3.2 mg g dw−1) relative to the western Shark River Slough transect (1.1 mg g dw−1), suggesting spatial variation in sources and/or depositional environments for iron. Further, these soil characteristics represent the collective, integrated signal of ecosystem structure, so any long-term changes in factors like water flow or water quality may be reflected in changes in bulk soil properties. Since the objective of current Everglades restoration initiatives is the enhancement and re-distribution of freshwater flows through the south Florida landscape, the antecedent soil conditions reported here provide a baseline against which future, post-restoration measurements can be compared.
Keywordssulfur iron phosphorus Everglades mangrove Florida Bay
Amador, J. A., Jones, R. D. 1993Nutrient limitations on microbial respiration in peat soils with different phosphorus contentSoil Biology & Biogeochemistry25793801CrossRefGoogle Scholar Bates, A. L., Orem, W. H., Harvey, J. W., Spiker, E. C. 2002Tracing sources of sulfur in the Florida EvergladesJournal of Environmental Quality31287299PubMedCrossRefGoogle Scholar Bates, A. L., Spiker, E. C., Holmes, C. W. 1998Speciation and isotopic composition of sedimentary sulfur in the Everglades, Florida, USAChemical Geology146155170CrossRefGoogle Scholar Benoit, J. M., Gilmour, C. C., Mason, R. P., Heyes, A. 1999Sulfide controls on mercury speciation and bioavailability to methylating bacteria in sediment pore watersEnvironmental Science and Technology33951957CrossRefGoogle Scholar Boyer, J. N., Fourqurean, J. W., Jones, R. D. 1997Spatial characterization of water quality in Florida Bay and Whitewater Bay by principal component and cluster analyses: zones of similar influence (ZSI)Estuaries20743758CrossRefGoogle Scholar Brown, K. E., Cohen, A. D. 1995Stratigraphic and micropetrographic occurrences of pyrite in sediments at the confluence of carbonate and peat-forming depositional systems, southern Florida, USAOrganic Geochemistry22105126CrossRefGoogle Scholar Chambers, R. M., Hollibaugh, J. T., Vink, S. M. 1994Sulfate reduction and sediment metabolism in Tomales Bay, CaliforniaBiogeochemistry25118CrossRefGoogle Scholar Chen, R., Twilley, R. R. 1999Patterns of mangrove forest structure associated with soil nutrient dynamics along the Shark River estuaryEstuaries2210271042CrossRefGoogle Scholar Childers, D. L., Doren, R. F., Jones, R., Noe, G. B., Rugge, M., Scinto, L. J. 2003Decadal change in vegetation and soil phosphorus pattern across the Everglades landscapeJournal of Environmental Quality32344362PubMedGoogle Scholar Chimney, M. J., Goforth, G. 2001Environmental impacts to the Everglades ecosystem: a historical perspective and restoration strategiesWater Science and Technology4493100PubMedGoogle Scholar Cline, J. D. 1969Spectrophotometric determination of hydrogen sulfide in natural watersLimnology & Oceanography14454459Google Scholar Coronado-Molina, C., Day, J. W., Reyes, E., Perez, B. C. 2004Standing crop and aboveground biomass partitioning of a dwarf mangrove forest in Taylor River Slough, FloridaWetlands Ecology and Management12157164CrossRefGoogle Scholar Davis, S. E., Cable, J. E., Childers, D. L., Coronado-Molina, C., Day, J. W., Hittle, C. D., Madden, C. J., Reyes, E., Rudnick, D., Sklar, F. 2004Importance of storm events in controlling ecosystem structure and function in a Florida gulf coast estuaryJournal of Coastal Research2011981208CrossRefGoogle Scholar DeBusk, W. F., Newman, S., Reddy, K. R. 2001Spatio-temporal patterns of soil phosphorus enrichment in Everglades Water Conservation Area 2AJournal of Environmental Quality3014381446PubMedGoogle Scholar Dodds, W. K. 2003The role of periphyton in phosphorus retention in shallow freshwater aquatic systemsJournal of Phycology39840849Google Scholar Ferdie, M., Fourqurean, J. W. 2004Responses of seagrass communities to fertilization along a gradient of relative availability of nitrogen and phosphorus in a carbonate environmentLimnology and Oceanography4920822094CrossRefGoogle Scholar Fourqurean, J. W., Boyer, J. N., Durako, M. J., Hefty, L. N., Peterson, B. J. 2003Forecasting responses of seagrass distributions to changing water quality using monitoring dataEcological Applications13474489Google Scholar Fourqurean, J. W., Zieman, J. C., Powell, G. V. N. 1992aRelationships between porewater nutrients and seagrasses in a subtropical carbonate environmentMarine Biology1145765Google Scholar Fourqurean, J. W., Zieman, J. C., Powell, G. V. N. 1992bPhosphorus limitation of primary production in Florida Bay: Evidence from the C:N:P ratios of the dominant seagrass Thalassia testudinum Limnology and Oceanography37162171CrossRefGoogle Scholar Jensen, H. S., McGlathery, K. J., Marine, R., Howarth, R. W. 1998Forms and availability of sediment phosphorus in carbonate sand of Bermuda seagrass bedsLimnology and Oceanography43799810CrossRefGoogle Scholar Koch, M. S., Benz, R. E., Rudnick, D. T. 2001Solid-phase phosphorus pools in highly organic carbonate sediments of northeastern Florida BayEstuarine, Coastal and Shelf Science52279291CrossRefGoogle Scholar Koch, M. S., Reddy, K. R. 1992Distribution of soil and plant nutrients along a trophic gradient in the Florida EvergladesSoil Science Society American Journal5614921499CrossRefGoogle Scholar Ku, T. C. W., Walter, L. M., Coleman, M. L., Blake, R. E., Martini, A. M. 1999Coupling between sulfur recycling and syndepositional carbonate dissolution: evidence from oxygen and sulfur isotope composition of pore water sulfate, south Florida platform, USAGeochemica et Cosmochimica Acta6325292546CrossRefGoogle Scholar Light, S. S., Dineen, J. W. 1994Water control in the Everglades: a historical perspectiveDavis, S. M.Ogden, J. C. eds. Everglades: The Ecosystem and its RestorationSt Lucie PressDelray Beach, FL4784Google Scholar McCormick, P. V., Rawlik, P. S., Lurding, K., Smith, E. P., Sklar, F. H. 1996Periphyton–water quality relationships along a nutrient gradient in the northern Florida EvergladesJournal of the North American Benthological Society15433449CrossRefGoogle Scholar Noe, G. B., Childers, D. L., Edwards, A. L., Gaiser, E., Jayachandran, K., Lee, D., Meeder, J., Richards, J., Scinto, L. J., Trexler, J. C., Jones, R. D. 2002Short-term changes in an oligotrophic Everglades wetland ecosystem receiving experimental phosphorus enrichmentBiogeochemistry59239267CrossRefGoogle Scholar Noe, G. B., Childers, D. L., Jones, R. D. 2001Phosphorus biogeochemistry and the impact of phosphorus enrichment: why is the everglades so unique?Ecosystems4603624CrossRefGoogle Scholar Noe, G. B., Scinto, L. J., Taylor, J., Childers, D. L., Jones, R. D. 2003Phosphorus cycling and partitioning in oligotrophic and enriched Everglades wetland ecosystems: a radioisotope tracing studyFreshwater Biology4819932008CrossRefGoogle Scholar Perry, W. 2004Elements of South Florida’s Comprehensive Everglades Restoration PlanEcotoxicology13185193PubMedCrossRefGoogle Scholar Romero, L. M., Smith, T. J., Fourqurean, J. W. 2005Changes in mass and nutrient content of wood during decomposition in a south Florida mangrove forestJournal of Ecology93618631CrossRefGoogle Scholar Ross, M. S., Reed, D. R., Sah, J. P., Ruiz, P. L., Lewin, M. 2003Vegetation:environment relationships and water management in Shark Slough, Everglades National ParkWetlands Ecology and Management11291303CrossRefGoogle Scholar Schwandes, L. P., Chen, M., Galbraith, J. 2001Total and extractable soil phosphorus in six ecological communities of FloridaSoil and Crop Science Society of Florida Proceedings605356Google Scholar Sherman, R. E., Fahey, T. J., Howarth, R. W. 1998Soil–plant interactions in a neotropical mangrove forest: iron, phosphorus and sulfur dynamicsOecologia115553563CrossRefGoogle Scholar SPSS, Inc.1999SPSS Base 10.0 for Windows User’s GuideSPSS IncChicago, ILGoogle Scholar Stookey, L. L. 1970Ferrozine – a new spectrophotometric reagent for ironAnalytical Chemistry42779781CrossRefGoogle Scholar Zhang, J. Z., Fisher, C. J., Ortner, P. B. 2004Potential availability of sedimentary phosphorus to sediment resuspension in Florida BayGlobal Biogeochemical Cycles18GB4008CrossRefGoogle Scholar