Soil surface elevation dynamics in a mangrove-to-marsh ecotone characterized by vegetation shifts

Rebecca J. Howard*, Andrew S. From, Ken W. Krauss, Kimberly D. Andres, Nicole Cormier, Larry Allain, Michael Savarese

*Corresponding author for this work

    Research output: Contribution to journalArticle

    Abstract

    Mangrove forest encroachment into coastal marsh habitats has been described in subtropical regions worldwide in recent decades. To better understand how soil processes may influence vegetation change, we studied soil surface elevation change, accretion rates, and soil subsurface change across a coastal salinity gradient in Florida, USA, an area with documented mangrove encroachment into saline marshes. Our aim was to identify if variations in the soil variables studied exist and to document any associated vegetation shifts. We used surface elevation tables and marker horizons to document the soil variables over 5 years in a mangrove-to-marsh transition zone or ecotone. Study sites were located in three marsh types (brackish, salt, and transition) and in riverine mangrove forests. Mangrove forest sites had significantly higher accretion rates than marsh sites and were the only locations where elevation gain occurred. Significant loss in surface elevation occurred at transition and salt marsh sites. Transition marshes, which had a significantly higher rate of shallow subsidence compared to other wetland types, appear to be most vulnerable to submergence or to a shift to mangrove forest. Submergence can result in herbaceous vegetation mortality and conversion to open water, with severe implications to the quantity and quality of wetland services provided.

    Original languageEnglish
    Pages (from-to)1087-1106
    Number of pages20
    JournalHydrobiologia
    Volume847
    Issue number4
    DOIs
    Publication statusPublished - Feb 2020

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    Keywords

    • Accretion
    • Coastal marsh
    • Mangrove forest encroachment
    • Sea-level rise
    • Subsidence
    • Vegetation change

    Cite this

    Howard, R. J., From, A. S., Krauss, K. W., Andres, K. D., Cormier, N., Allain, L., & Savarese, M. (2020). Soil surface elevation dynamics in a mangrove-to-marsh ecotone characterized by vegetation shifts. Hydrobiologia, 847(4), 1087-1106. https://doi.org/10.1007/s10750-019-04170-4