Natural History and Sites of Historic Interest
The Estate is situated a few miles north of Chichester on the western South Downs, stretching 6 miles (9 kilometres) from the southern shallow ‘dip’ slope to the northern steep ‘scarp’ slope.
Two major valleys run through it, the now dry Chilgrove valley and the winterbourne Lavant valley. The hills on the Estate are rounded with steep slopes and consist of middle and upper chalk interspersed with patches of clay with flints. Coombe deposits, valley gravels and alluvium occur in the valleys. The soils are mainly rendzinas and most of the land is classified as Grade III for agricultural purposes. The altitude ranges between 38 and 280 metres above sea level with a climate mid-way between the more oceanic west and the continental eastern counties. Frost and salt-laden winds affect tree growth, and sunshine levels are reduced by mist hanging in the coombes.
The Estate contains a variety of habitats. Houses, barns, workshops, studios, sheds, garden and Park walls, church and churchyard all provide urban habitat. Freshwater habitat varies during the year since the River Lavant which flows through West Dean is a winterbourne, typically flowing during the winter months only and drying out each summer. A few small ponds dotted around the Estate and a relatively new wildlife pond within West Dean Gardens provide year round freshwater habitat. Woodland habitat is varied, with scrub, coppice, coppice-withstandards, yew, yew and ash woodlands, mixed broadleaf and conifer, pure conifer and high forest beech all occurring. Although many of the plantations are of even age as a consequence of re-establishment after the 1987 and 1990 storms, the Estate taken as a whole provides trees of a range of ages and consequently a range of habitats. Hedgerows, shelterbelts, ornamental clumps, parkland trees and specimen trees in the Gardens and Arboretum complement the larger commercial plantations whilst old watered meadows, chalk downland, chalk heath, grassy road verges, improved pastures and fields of arable crops provide further variety of habitat.
The diversity of wildlife reflects this variety of habitat. The Estate is rich in fungi and flowering plants, particularly orchids, and lichens, bryophytes and ferns. It also supports a large invertebrate population, including flies, bees, grasshoppers and butterflies. Many species of mammals, small birds and raptors occur on the Estate, notably water vole, badgers, three species of deer, various tit species, ravens, buzzards, kestrels and red kites. Moderate populations of reptiles and amphibians also occur.
The development of the landscape from prehistoric times to the present day has been studied in detail and reported in a number of publications and scientific journals.
