Restoration of Heathland

The characteristic plants of heathlands all favour acid soils, poor in plant nutrients. Establishment of heathland is therefore dependent on the existence of such conditions. These conditions are actually fairly rare in England in modern times because so much of the land has been agriculturally improved at one time or another.

Land planted with commercial crops is usually artificially fertilised to improve soil fertility. Soil acidity is also frequently decreased by the application of lime (calcium oxide). Resultant high soil nutrient and pH levels are potentially the most difficult inhibiting factors to overcome on sites designated for heathland regeneration.

If soils are too fertile for the successful growth of heathland plants, several years of continuous cropping, without the addition of extra fertilisers, will eventually deplete soil nutrients to suitable levels for heathland regeneration. Alternatively, top-soil layers can be stripped off to remove the nutrients concentrated in the upper layers of the soil (turf-stripping). This may have the added advantage of exposing heather seeds buried in the soil.

Old heathland sites which have been converted to agriculture or forestry within the last 50 or so years are quite likely to still have a viable heather seed bank in the soil. The seeds require light for germination. Stripping off the upper layers of the soil may thus expose long-buried seeds to the light, promoting their germination.

Where a viable seed bank no longer remains, various methods exist for importing seeds from remnant heathland sites. These include importing turves, top soil or heather cuttings. The smallest disturbance to existing sites is caused by the transfer of heather cuttings. This is best carried out in November / December, when there is the best chance of obtaining mature seed. Obviously, remnant heathland sites are vitally important as sources of seed for the restoration of new sites.

The vegetation cover already present on sites designated for restoration may need to be altered if successful regeneration is to occur. Where too many trees are present, some will need to be removed to increase ground light levels for Heather and other heath species. (It may be advantageous to leave a few to provide perches and a source of insects for food for birds.) Rhododendron, a species which thrives on acid soils, may also present problems if present on a site. It spreads rapidly and can quickly come to dominate an entire area if not properly controlled. Bracken, while it is a natural component of heathlands, may also need to be controlled to allow other heath species to develop.