The subdivision of commonable properties from the end of the 19th century onwards significantly increased the number of Commoners. However, this increase was accompanied by a sharp decline in Commoners' exploitation of their Rights of Common on the Forest, which became most marked after World War II. Those Commoners who operated smallholdings around the Forest (often with a hand to mouth existence of endless graft and little comfort in old age) found that they were becoming unable to compete with cheaper produce. An increasingly scientific approach to agriculture, with high productivity being the only route to profitability, left the Commoners with no market and expensively produced local food could not compete with cheap imports. Many decided to give up their onerous work for good and moved to jobs in nearby towns and cities or else retired, in some cases selling up to commuters looking for an attractive country retreat. As the Commoners moved out, the commuters moved in as the Forest was within easy travelling distance to London and offered a haven from city life.
Unfortunately, the rapid decline in the Commoner life-style had a major negative impact on the Forest's landscape and ecology as, without human intervention, heathland becomes old and woody, bracken spreads and scrubby birch and other trees invade. A rapid loss of the Forest's open heathland to scrub and trees took place from the late 1940s onwards, threatening the many specialised and rare plants and animals that depend on the heathland and jeopardising the Forests' famous open landscape with its magnificent vistas, so well captured in Shepherd's Winnie-the-Pooh illustrations.
The Board of Conservators has been forced, in recent years, to move beyond its original administrative and regulatory functions to play a much more active, interventionist role in combating the invasion of scrub and trees and returning the heathland to favourable condition.