Spatially-dependent patterns of plant recovery and sediment accretion following multiple disturbances in a Gulf Coast tidal marsh

• Published in: Wetlands ecology and management Vol. 27; no. 2-3; pp. 377 - 392
• Main Authors: Braswell, Anna E., May, Christopher A., Cherry, Julia A.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-06-2019; Springer Nature B.V
• Subjects: Accretion; Anthropogenic factors; Biomass; Biomass burning; Biomedical and Life Sciences; Brackishwater environment; Coastal marshes; Coastal zone management; Coasts; Conservation Biology/Ecology; Dependent variables; Deposition; Disturbances; Elevation; Environmental Law/Policy/Ecojustice; Estuaries; Estuarine environments; Fires; Freshwater & Marine Ecology; Habitat selection; Hurricanes; Hydrology/Water Resources; Life Sciences; Marine & Freshwater Sciences; Marshes; Organic matter; Original Paper; Recovery; Sea level; Sediment; Sediments; Shorelines; Soil; Soil erosion; Soil surfaces; Tidal marshes; Water Quality/Water Pollution; Wetlands; Plant production; Accretion; Coastal wetland; Disturbance; Fire; Marsh; Hurricane
• ISSN: 0923-4861; 1572-9834
• DOI: 10.1007/s11273-019-09666-3

Coastal wetlands are projected to experience increases in anthropogenic and climatic disturbances, which may alter plant-sediment feedbacks critical for maintaining marsh resilience to sea level. To study the effects of disturbance on ecogeomorphic processes, we examined aboveground plant responses and sediment accretion in three locations relative to the shoreline (low, mid, and high) within a tidal marsh at Grand Bay National Estuarine Research Reserve, Mississippi, USA. This study site was affected by two hurricanes in the fall of 2008, and subsequently burned as part of a controlled experiment in January 2009, permitting examination of the effects of two disturbance types on aboveground plant responses and vertical accretion. Fire and hurricanes affected these response variables differently, with effects dependent on location within the marsh. Fire significantly reduced standing aboveground biomass, and subsequent recovery of vegetation relative to pre-burn levels was faster in low marsh plots nearest to the shore than in high marsh plots closest to the marsh-pine ecotone. Hurricanes introduced sediment to the marsh platform, resulting in greater accretion in low marsh plots that had more standing biomass and higher stem densities than high marsh plots. Collectively, these results demonstrate that disturbances can heterogeneously affect surface soil-building processes in marshes through effects on sediment and organic matter accumulation, which may have important consequences for surface elevation maintenance in coastal marshes.