Chalk grassland was once prevalent throughout much of the Kent Downs as large areas were under permanent sheep or cattle grazing at the time. The combination of continual grazing and the nutrient poor conditions of the downlands produced a short turf (or sward) and allowed a variety of herbs, flowers and grasses to flourish.
Since the early 19th century, much land has been converted to arable. In other areas, farming intensification has led to the widespread use of inorganic fertilisers to improve the quality of grazing so that more livestock can be reared than would be possible under natural conditions. Unfortunately, this has allowed more vigorous grasses to dominate, upsetting the previous delicate balance of vegetation. Today, there are now only 700 ha of unimproved chalk grassland left within the Kent Downs AONB, of which 60% are designated Sites of Special Scientific Interest (SSSIs). These few remaining areas occur primarily on the steep scarp slopes where cultivation is not always possible, though even these are under threat.
With time limitations and facing cheaper imports from abroad, it has become less viable to rear sheep and, today, the British wool market is desperately in need of restoration. With the lack of grazing, coarse grasses and scrub begin to dominate (a process known as vegetation succession) until the chalk downland is lost to scrub.
Unimproved chalk grassland is a unique, specialised and fragile ecosystem. Many of the plants are specifically adapted to survive in the poor alkaline soils, where the porous chalk underneath results in localised drought conditions in the summer. As a result, such plants find it hard to live anywhere else. Perhaps the most famous are the rare and beautiful orchids. These include the fragrant, pyramidal, bee, lady and man orchids, all regularly found in the Kent Downs.