Eco-hydrological interactions within a sand dune system in South East England

The research was undertaken at a sand dune system located along the South East coast of England, known as Sandwich Bay. Sandwich Bay has attracted a number of environmental designations, including Special Areas of Conservation and a Site of Special Scientific Interest due to the presence of rare habitats and flora found predominantly at this single site, such as Himantoglossum hircinum (lizard orchid) and Orobanche caryophyllacea (bedstraw broomrape). The research focus centred on concerns surrounding ecological change resulting in the loss of grey dunes, an Annex 1 priority feature. Sandwich Bay has been classed as a Special Site of Scientific Interest in unfavourable condition (Natural England, 2014), based primarily upon the loss of fixed grey dune habitats to neutral grasslands (SD8 to MG1/MG12 NVC classifications).

The aim was to identify causative factors that might account for the observed historic and any current changes in vegetation. The research was conducted between October 2011 and September 2014, and focused upon hydro-chemical interactions in the environment. Analysis was undertaken by the installation of 103 dipwells across the 520 ha site, in order to obtain groundwater samples. The hydro-chemical and botanical analysis indicated that the vegetation composition was not affected significantly by the chemical constituents within the groundwater. However vegetation composition was significantly modified by variable surface elevation and the related height of the water table. An additional investigation focused upon the identification of management techniques that are thought to be beneficial to dune vegetation restoration. Three management trials were located at three different sites, investigating four different management treatments. Analysis showed that there was a significant difference between the various management treatments and species composition. Vegetation analysis indicated that both cut and remove, and burning, as management treatments encouraged a greater diversity of species, particularly in sheltered eutrophic areas.