In Britain hay meadows are typically meadows with high botanical diversity supporting a diverse assemblage of organisms ranging from soil microbes, fungi, arthropods including many insects through to small mammals such as voles and their predators, and up to insectivorous birds and bats.
Even in the towns and cities, many horses were still in use pulling carriages and carts and delivering milk and bread to the door and Pit ponies were in widespread use in all the coal mining regions.
The two world wars made enormous technological strides in devising mechanised forms of transport which were built on to provide oil powered farm equipment including the ubiquitous tractors.
Without the need to feed horses, there was no apparent need to maintain hay-meadows and most were ploughed up and re-sown to provide fodder crops such as mono-culture grass species for silage, brassica or turned over to direct food production such as cereal crops, potatoes or oil-seed rape.
The presence of hemi-parasitic plants such as Yellow Rattle and Eye-bright assist in controlling over-growth of grasses.