the extent to which considering saltmarsh elevations alters estimates of the ecosystem services that provide in the UK, using saltmarsh elevations and local tidal levels
Salt marshes are ecologically important providing a wide array of benefits to ecosystem services, including shoreline protection, carbon sequestration, and wildlife habitat provision. This thesis examined the extent to which considering saltmarsh elevations alters estimates of the ecosystem services that provide in the UK, using saltmarsh elevations and local tidal levels. The Digital terrain model (DTMs) was confirmed to be more reliable than the Digital terrain model (DSMs) to estimate elevations of the surface of the sediment on the marsh closely to the reality with accuracy less than 20 cm. saltmarsh elevations can determine marsh platforms and their abilities of reducing risks of flooding. Most of marsh platforms from the Tees Estuary on the East coast moving in clockwise to the Dovey Estuary on the West coast occur at or below the level of MHWS, and these marshes can be effective against flooding during normal condition but their contribution in reducing risks of flooding is much less important during storm surge events. The variations of saltmarsh elevation are partly effective of decrease the water depth across saltmarsh which result in reducing wave energy. However, once marshes submerged by more than 2 m during storm surges, their effectiveness will be limited to reducing flooding risks. Most of the marshes here have predictably high redox which indicated that lower GHG emissions reduced. Saltmarsh elevations can determine the amount of sediment that is deposited across marshes, and sedimentation can be occurred in different parts of the marshes whether in the high or low marshes leading to variations of the amount of carbon burial and GHG emissions of the whole marsh. Mechanisms of sedimentation and vegetation succession appear to be variable and unstable, whether across the whole saltmarsh or of different parts in an individual marsh.