Document Type

Article

Department/Program

Virginia Institute of Marine Science

Publication Date

2016

Journal

ECOLOGY AND EVOLUTION

Volume

6

Issue

9

First Page

2948

Last Page

2956

Abstract

The interplay between storms and sea level rise, and between ecology and sediment transport governs the behavior of rapidly evolving coastal ecosystems such as marshes and barrier islands. Sediment deposition during hurricanes is thought to increase the resilience of salt marshes to sea level rise by increasing soil elevation and vegetation productivity. We use mesocosms to simulate burial of Spartina alterniflora during hurricane-induced overwash events of various thickness (0-60 cm), and find that adventitious root growth within the overwash sediment layer increases total biomass by up to 120%. In contrast to most previous work illustrating a simple positive relationship between burial depth and vegetation productivity, our work reveals an optimum burial depth (510 cm) beyond which burial leads to plant mortality. The optimum burial depth increases with flooding frequency, indicating that storm deposition ameliorates flooding stress, and that its impact on productivity will become more important under accelerated sea level rise. Our results suggest that frequent, low magnitude storm events associated with naturally migrating islands may increase the resilience of marshes to sea level rise, and in turn, slow island migration rates. Synthesis: We find that burial deeper than the optimum results in reduced growth or mortality of marsh vegetation, which suggests that future increases in overwash thickness associated with more intense storms and artificial heightening of dunes could lead to less resilient marshes.

DOI

10.1002/ece3.2024

Keywords

SALT-MARSH; BARRIER-ISLAND; ATLANTIC COAST; NORTH-CAROLINA; SEDIMENTATION; LANDSCAPE; STABILITY; ELEVATION; RESPONSES; DYNAMICS

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

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