In the Neolithic period, Stone Age people began to settle on the plain, most likely centred around the causewayed enclosure of Robin Hood's Ball.
By 2500 BC areas around Durrington Walls and Stonehenge had become a focus for building, and the southern part of the plain continued to be settled into the Bronze Age.
In September 1896,[5] George Kemp and Guglielmo Marconi experimented with wireless telegraphy on Salisbury Plain, and achieved good results over a distance of 1.25 miles (2.0 km).
The plain supports the largest known expanse of unimproved chalk downland in north west Europe, and represents 41% of Britain's remaining area of this wildlife habitat.
A large proportion of Salisbury Plain supports upright brome (Bromus erectus) species-rich grassland, within which a continuous floristic variation is seen.
A widespread type on the plain is characterised by an abundance of red fescue (Festuca rubra), crested hair-grass (Koeleria macrantha), salad burnet (Sanguisorba minor), lady's bedstraw (Galium verum), rough hawkbit (Leontodon hispidus), common rock-rose (Helianthemum nummularium) and dropwort (Filipendula vulgaris).
[3] The rare and notable plants which occur here include burnt-tip orchid (Neotinea ustulata), slender bedstraw (Galium pumilum), field fleawort (Senecio integrifolius) and the nationally scarce British endemic early gentian (Gentianella anglica).
Particularly associated with long established turf on thin rendzina soils, and rabbit-grazed areas of the eastern and central ranges, are low-growing perennials including squinancy-wort (Asperula cynanchica), chalk milkwort (Polygala calcarea), dwarf thistle (Cirsium acaule), wild thyme (Thymus praecox), the nationally scarce bastard toadflax (Thesium humifusum) and purple milk-vetch (Astragalus danicus) in its most southerly British station.
[3] Devil's-bit scabious (Succisa pratensis), saw-wort (Serratula tinctoria) and betony (Stachys officinalis) are all abundant and exemplify the oceanic character of the chalk grassland on the plain, a feature which is confined to South West England.
Herb diversity is generally lower in the tall, upright brome-dominated swards, but wild parsnip (Pastinaca sativa), hogweed (Heracleum sphondylium) and greater knapweed (Centaurea scabiosa) are characteristic.
[3] On anthills, and in the more disturbed turf that is especially a feature of the impact area, mouse-ear hawkweed (Hieracium pilosella) is abundant together with sheep's fescue (Festuca ovina) and wild thyme.
Annuals are also characteristic of this habitat, including common whitlowgrass (Erophila verna), rue-leaved saxifrage (Saxifraga tridactylites,) hairy rock-cress (Arabis hirsuta) and the nationally scarce dwarf mouse-ear (Cerastium pumilum) and fine-leaved sandwort (Minuartia hybrida).
A very local community characterised by a lichen-rich turf (Cladonia species) and the broom moss (Dicranum scoparium) is found in some stabilised missile-impaction craters on the central ranges.
[3] Salisbury Plain supports a diverse bryophyte flora with seven nationally scarce species which have seen a general decline in other chalk grassland sites, including Barbula acuta, Phascum curvicolle, Pleurochaete squarrosa, Thuidium abietinum and Weissia sterilis.
Both pyramidal and prostrate forms are present and this site, along with Porton Down SSSI to the south, supports the best remaining examples of the lowland type of juniper associated with chalk and mixed scrub in England.
A high concentration of colonies of three nationally scarce species, the Adonis blue (Polyommatus bellargus), Duke of Burgundy (Hamearis lucina), and the largest population of marsh fritillary (Euphydryas aurinia) on the chalk, occur.
The RDB species scarce forester (Adscita globulariae) is present, and amongst many species of nationally scarce moths are the cistus forester (Adscita geryon), six-belted clearwing (Bembecia scopigera), oblique striped (Phibalapteryx virgata), pimpernel pug (Eupithecia pimpinellata), shaded pug (Eupithecia subumbrata) and narrow-bordered bee hawk moth (Hemaris tityus).
[3] Recent observations have shown that Salisbury Plain is an important site for the RDB crustacean, the fairy shrimp Chirocephalus diaphanus which is dependent on temporary pools, a rare and declining habitat.
On the plain this habitat requirement is met by numerous pools created by repeated tank movements along the earth tracks which cross the chalk grassland.
Barred grass snake (Natrix helvetica) are also often seen near pools, and common lizard (Lacerta vivipara), slowworm (Anguis fragilis) and adder (Vipera berus) are present.