Brownsea Island It is within the South Dorset constituency of the House of Commons and the South West England constituency of the European Parliament. Brownsea Island has built up on a bare sand and mud bank deposited in the shallow harbour. Ecological succession has taken place on the island to create topsoil able to support ecosystems. The nature reserve on the island is leased from the National Trust by Dorset Wildlife Trust. This reserve includes a brackish lagoon and area of woodland. Other ecosystems on the island include salt marsh, reedbed, two freshwater lakes, alder carr, coniferous woodland, deciduous woodland and arboretum.
Brownsea Island in winter, when more than 50 per cent of British bird species (over 1500) can be present. Some imported stonework and statuary on the island serves as a habitat for a Mediterranean land snail, "Papillifera bidens". The first records of inhabitants on Brownsea Island occurred in the 9th century, when a small chapel and hermitage were built by monks from Cerne Abbey near Dorchester. The chapel was dedicated to St Andrew and the only resident of the island was a hermit, who may have administered to the spiritual welfare of sailors passing through Poole Harbour. In 1015, Canute led a