Lowland heath

Lowland Heath is a Biodiversity Action Plan habitat as it is a type of ancient wild landscape. Natural England's Environmental Stewardship scheme describes lowland heath as containing dry heath, wet heath and valley mire communities, usually below 250 metres in altitude, on acidic soils and shallow peat, typically comprising heathers, gorses, fine grasses, wild flowers and lichens in a complex mosaic. Heathers and other dwarf shrubs usually account for at least 25% of the ground cover. By contrast, upland heath, which is above 300 metres in altitude, is called Moorland, Dartmoor being an example.

Lowland heath occurs on a range of acidic pH < 5, impoverished soils that are often sandy and free draining, characteristically podsols. There are no deep-burrowing earthworms so soil profile boundaries are sharp. There is often a thick litter layer on top of slow-decaying leaf litter . The habitat is susceptible to drought in summer and due to its freely draining nature. As many of the plants are waxy, fire is a hazard. A plant-animal association has adapted to these harsh conditions.

There are three types of lowland heath according to their location and climate conditions: wet (impervious rocks/clay preventing water drainage), dry (well drained), and humid (between the two types). Wet heaths contain more different species than dry, such as sphagnum mosses and carnivorous plants (Drosera, Pinguicula).

Some 80% of lowland heath has been lost since 1800, with the UK holding a fifth of the world's remaining stock. Pollen grain carbon dating has indicated that it has existed in the UK for 14,000 years as the ice-caps retreated. As the weather warmed, trees became established and replaced the tundra heath. But 5000 years ago man began to clear forests, and heathland re-established on acid, sandy soils. Its area is thought to have peaked around the 16th century (Tubbs, 1991). From then onwards agricultural and transport technology improved, allowing nutrients to be put back into the soil, nonheathland type crops to grow, or the heath was simply no longer managed as in the past.

Heathland succession moves from grasses and bracken to gorses and heather, and finally to woodland (birch, pine and oaks).

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