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.
Geography of Dorset South Haven Point, is narrow, less than 0.25 miles across. Its shoreline is irregular and heavily indented with numerous small inlets and channels, between which many small peninsulas extend out into the body of the harbour. The harbour also houses several small islands, the largest of which is Brownsea Island. Chesil Beach is a barrier beach on the southwest coast of the county. It is long and stretches between West Bay and the Isle of Portland, although the name Chesil Beach is often only applied to the stretch south-east of Abbotsbury, where it is separated from the land behind it