• Login
    View Item 
    •   SMARTech Home
    • College of Sciences (CoS)
    • School of Biological Sciences
    • School of Biology Faculty Publications
    • View Item
    •   SMARTech Home
    • College of Sciences (CoS)
    • School of Biological Sciences
    • School of Biology Faculty Publications
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Impact of fiddler crabs and plant roots on sediment biogeochemistry in a Georgia salt marsh

    Thumbnail
    View/Open
    kostka_IR_2003_001.pdf (922.0Kb)
    Date
    2003-09-12
    Author
    Gribsholt, Britta
    Kostka, Joel E.
    Kristensen, Erik
    Metadata
    Show full item record
    Abstract
    The influence of macrofauna and macrophytes on sediment biogeochemistry was quantified in a Spartina alterniflora (Loisel) saltmarsh, with emphasis on sulfur and iron cycling. Vertical profiles of sediment geochemistry and rates of microbial metabolism at 3 sites with different abundances of fiddler crab Uca pugnax burrows, vegetation coverage and hydrology were supplemented with high-resolution radial profiles around burrow walls and S. alterniflora roots. Carbon oxidation was measured as sulfate reduction using the 35S technique, as total anaerobic CO2 production, and as Fe(III) reduction by monitoring Fe(II) evolution. Depth-integrated (0 to 10 cm) sulfate reduction was 25% lower, while total Fe and Fe(III) concentrations were 1.5 and 6 times higher, respectively, in bioturbated than in nonbioturbated sediment. Low sulfate-reduction rates adjacent to burrow walls (3% of those in bulk sediment) were counteracted by very high Fe(III) reduction rates. Thus, Fe(III) reduction accounted for 54 to 86% of the total carbon oxidation within 4 cm distance of burrows, decreasing in importance with distance from the burrow wall. Overall, S. alterniflora roots showed a greater impact on sediment biogeochemistry than crab burrows. Sulfate reduction was almost absent in the rhizosphere, whereas Fe(III) reduction rates (6.2 µmol Fe cm-3 d-1) were among the highest reported for marine sediments, accounting for >99% of carbon oxidation. Our results confirm the universal relationship between the contribution of Fe(III) respiration to total carbon oxidation and solid Fe(III) concentrations that has been suggested based on studies of subtidal marine sediments. The importance of Fe(III) respiration was strongly dependent on Fe(III) concentrations below levels of 30 µmol cm-3, whereas above this level almost all anaerobic respiration was mediated by Fe(III) reduction in saltmarsh sediments.
    URI
    http://hdl.handle.net/1853/42117
    Collections
    • School of Biology Faculty Publications [227]

    Browse

    All of SMARTechCommunities & CollectionsDatesAuthorsTitlesSubjectsTypesThis CollectionDatesAuthorsTitlesSubjectsTypes

    My SMARTech

    Login

    Statistics

    View Usage StatisticsView Google Analytics Statistics
    facebook instagram twitter youtube
    • My Account
    • Contact us
    • Directory
    • Campus Map
    • Support/Give
    • Library Accessibility
      • About SMARTech
      • SMARTech Terms of Use
    Georgia Tech Library266 4th Street NW, Atlanta, GA 30332
    404.894.4500
    • Emergency Information
    • Legal and Privacy Information
    • Human Trafficking Notice
    • Accessibility
    • Accountability
    • Accreditation
    • Employment
    © 2020 Georgia Institute of Technology