Deltaic floodplain wetland vegetation dynamics along the sediment surface elevation gradient and in response to disturbance from river flooding and hurricanes in Wax Lake Delta, Louisiana, USA

Bevington, A.; Twilley, Robert R.; Sasser, Charles E.

doi:10.1016/j.geomorph.2021.108011

Cited by 9 publications

(2 citation statements)

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“…Our study showed that vegetation in the ADB fresh site displayed a distinct zonation along the elevation gradient, from higher elevation (marsh edge) to lower elevation in the intermediate intertidal zone (Appendix S2: Fig.S2B). This result is supported by previous studies in WLD that have documented shifts in plant community composition and distribution over timeBevington et al 2022), speci cally species like P. nodosus and emergent Nelumbo lutea spreading over much of the lower elevation areas of the delta previously dominated by Sagittaria spp., grasses, and forbs (like Polyganum spp.) dominating intermediate elevations, and C. esculenta and woody S. nigra growing along higher elevation on channel levees(Carle 2013;Jensen et al 2021…”

supporting

confidence: 87%

“…These ecogeomorphic feedbacks between vegetation productivity and surface elevation change can be greatly affected by environmental stressors such as excessive salinity and ooding, temperature changes with seasonality, and exposure to hurricanes and drought events (Day et al 2011;Silliman et al 2019; Bevington et al 2022). These factors can change vegetation community structure, species distribution, and plant biomass and productivity (Holm and Sasser 2001;Carle 2013;Snedden et al 2015).…”

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confidence: 99%

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Biomass and carbon stocks in deltaic wetlands across active and inactive basins in the Mississippi River Delta, USA

Solohin

Castañeda‐Moya

Twilley

et al. 2023

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Deltaic wetlands in coastal Louisiana are experiencing widespread changes in vegetation dynamics and distribution due to rising sea level and long-term modifications in hydrology and sediment supply. Using field and remote sensing data, we investigated how aboveground biomass (AGB) and C stocks change in response to seasonality along salinity and soil nutrient gradients across different wetland habitats in two coastal basins with active (Atchafalaya - AB) and inactive (Terrebonne - TB) hydrological regimes. The highest seasonal changes in AGB and C stocks across both basins occurred in saline (SL) sites (AGB range: 343 ± 101 to 1214 ± 210 g m− 2) in early growing and peak biomass season, respectively. Biomass productivity rates varied across basins, with SL sites being the most productive, albeit less species-diverse. Foliar nutrient uptake was higher in the mineral-rich soils of AB freshwater (FW) site. In contrast, Terrebonne FW plants (as well as brackish and SL) had lower tissue nutrients and higher biomass allocation, indicating greater nutrient use efficiency with increasing salinity stress. Seasonal variation in AGB was positively correlated with porewater salinity and with soil nutrients (total nitrogen (N) and phosphorus). As hypothesized, changes in plant and soil isotopic signatures in both basins paralleled the spatiotemporal patterns in environmental stressors (e.g., elevated salinity and nutrient availability). Our findings show that in both active and inactive coastal delta basins, herbaceous wetlands maintain high biomass and C stocks by developing adaptive strategies in response to the distribution of environmental stressors and availability of resources.

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confidence: 87%