Natural History

Although some plants and animals cannot tolerate an urban environment, many thrive in the warmth generated by people and buildings, together with abundant food and shelter. As well as extensive heathland, there are several different freshwater habitats on the Common ranging from bogs and streams to a fairly deep artificial lake. The ability of plants to grow, and hence the variety of animals, depends on the depth of water and rate of flow or stagnancy. These affect the amounts of light and oxygen in the water, and of silt on the floor. There are considerable seasonal variations. Acidic bogs are always wet but rarely flood attracting a variety of rushes, sedges and horsetail. On the other hand water flows slowly or is still in small streams and drainage ditches where liverworts and mosses grow on their steep and shady banks.

In addition to the many varieties of trees on the Common there are various types of grassland such as the mown areas of playing fields and golf courses to typical heathland. In several places these are bordered by hedgerows. The many flowering plants and the undergrowth also provide food and shelter to butterflies, grasshoppers, bumble bees and other insects. If the grass is not mown or grazed then shrubs and trees soon encroach to turn it back into woodland.