Manipulation of Water Levels to Facilitate Vegetation Change in a Coastal Lagoon Undergoing Partial Tidal Restoration (Cape Cod, Massachusetts)

Abstract

I www.JCRonline.org Smith, S. and Medeiros, K., 2013. Manipulation of water levels to facilitate vegetation cbange in a coastal lagoon undergoing partial tidal restoration (Cape Cod, Massacbusetts) Journal of Coastal Research, 29(6A), 93-99. Coconut Creek (Florida), ISSN 0749-0208.East Harbor is a back-barrier coastal lagoon and salt marsb witbin Cape Cod National Seashore (Massachusetts), wbicb has been undergoing partial tidal restoration since 2002. The current tidal exchange has been sufficient to elevate salinities in tbe open lagoon but is still too constrained by the present infrastructure to create high tides sufficient to flood the peripheral marsh areas. Consequently, an adaptive management strategy using a one-way tide gate was implemented in 2011 that let high tides into the system while blocking tbeir escape. Tbe increased flooding of tbe marsh, above and beyond wbat the current engineering of the system could provide hy opening the restrictive culvert, raised porewater salinities in many areas and resulted in decreases in the cover of freshwater and brackish-water plant taxa-a necessary precursor for the establishment and expansion of native halophytes. This kind of adaptive-management tool can be used to enhance salt marsh restoration in systems tbat can only be partially restored tidally.

Effects of tidal re-introduction design on sedimentation rates in previously embanked tidal marshes

“…Most restoration efforts along the North Atlantic coast of North America and in Australia include restoring tidal flow by placement of culverts or removing/opening tide gates (Bakker and Piersma, 2006;Fell et al, 2000;Haines, 2013;Reiner, 2012;Sinicrope et al, 1990;Smith and Medeiros, 2013;Warren et al, 2002;Winning and Saintilan, 2009). Furthermore, reinstating the tide has been realized using self-regulating tide gates (SRT) in US tidal marshes (Connecticut, (Giannico and Souder, 2005;Roman et al, 1984;Rozsa, 1995Rozsa, , 2012; Rhode Island (DiQuinzio et al, 2002); Massachusetts, (Reiner, 2012); Oregon, Washington state, (Giannico and Souder, 2005), Maine (Adamowicz and O'Brien, 2012) and Australia (Glamore, 2012;Russell et al, 2012).…”

Evaluating the viability of coastal wet grassland to a changing management regime through flood hazard modelling

“…Over the last couple of decades, thinking about the potential impacts of climate change on tidal wetland restoration has evolved from a general awareness to a central focus in the design of ecological engineering projects, especially on the long-term sustainability of restored tidal wetlands (Parker et al, 2012). In this sense, restoration has become much more focused on creating conditions that will develop sustainable and resilient plant communities rather than designing specific historical communities for restoration projects (Critchley et al, 2003;Toogood and Joyce, 2009;Palaima, 2012;Smith & Medeiros, 2013;Hayes et al, 2015). Our results have direct implications for ecological engineering and the maintenance of tidal wetland plant communities' characterised by high biodiversity/resilience to the more frequent inundation effects caused by global warming.…”

Inundation depth and duration impacts on wetland soils and vegetation : state of knowledge

“…Snedden, Cretini, and Patton (2015) also reported that prolonged inundation of S. patens could result in approximately 90% reduction in belowground biomass, leading to substantial reductions in soil shear strength and erosional resistance. Conversely, Smith and Medeiros (2013) report that discrete stands of S. alterniflora were better able to tolerate constant immersion for 2.5 months without any visible signs of stress. It is assumed that this resilience to inundation is capable over the course of one growing season, but even tolerant plants could not withstand multiple years of persistent inundation (Smith and Medeiros 2013).…”

“…Conversely, Smith and Medeiros (2013) report that discrete stands of S. alterniflora were better able to tolerate constant immersion for 2.5 months without any visible signs of stress. It is assumed that this resilience to inundation is capable over the course of one growing season, but even tolerant plants could not withstand multiple years of persistent inundation (Smith and Medeiros 2013).…”