Greenham Common is being transformed into a flower-rich heathland. It' s an ambitious and fragile project

Endangered habitats

The peace campaigners who spent so much of their lives on the outside of the security fence around Greenham Common Airbase may soon have a fitting epitaph. For the huge concrete runway - the longest in Europe - along which B52 bombers armed with cruise missiles once hurtled, is being transformed, bit by bit, into flower-rich heathland.

If all of the four-kilometre-long runway and its adjacent taxi-ways are dug up, 60 or so hectares of heathland - rich with heathers, gorse, knapweeds and gentians - could replace them. The scheme has been promoted by English Nature with the backing of Newbury District Council, and the MoD who still own the land.

Sixty hectares of new heathland may not sound much. But, set in the context of the huge area of this exceedingly rich wildlife habitat destroyed over the last century, it's a substantial reversal in fortunes.

Much of Egdon Heath (immortalised by Thomas Hardy in The Return of the Native) has been ploughed up to grow cereals and other crops, planted with conifers, dug out for its underlying gravel, and developed for housing and industry. Some has been lost, too, by scrub encroachment, converting it into wildlife-poorer birch or pine woodland. Only about a fifth of the area Hardy knew still remains, most of it in small fragments.

Such destruction of heathland has happened elsewhere - on the west coast of Wales, in the Brecklands of East Anglia, on the Cornish coast, in Surrey and in Hampshire: the areas of Britain where the habitat is concentrated. Of the 58,000 hectares of lowland heath now left in Britain, over half of it is in England. This is 40 per cent of the European total. Not all of it is protected by wildlife designations or by planning policies.

The Government-appointed Biodiversity Steering Group has recommended an Action Plan for lowland heathland which could cost between half a million and five million pounds a year, depending upon land purchase and management costs. As a minimum, the Steering Group proposes that all remaining lowland heathland should be protected and properly managed to retain its wildlife and that a further 6,000 hectares should be re-established. Greenham Common is such an example.

Yet even this ambitious programme is comparatively small beer. There is an estimated 67,000 hectares of recently modified heathland ripe for restoration.

"At Greenham," says Dr Wanda Fojt, English Nature's Conservation Officer for Berkshire, "as the concrete is removed, the plants from the heathland surrounding the runways should colonise naturally. We may have to help by spreading some heather seed. The heathland at the base was cut regularly in the past so scrub hasn't been a problem. But outside the base, some of the heath has been taken over by birch."

Heathland developed, often over millennia, from cleared forest. Historically it has been maintained by grazing with cattle, sheep or ponies. An ancient triumvirate of shepherd, sheep and heathland has produced a clutch of names for flowers that colour it, such as Shepherd's Bedstraw, Shepherd's Knot, and Sheep's Bit.

Lowland heath in summer can be a magnificent extravagance of purples, yellows, pinks and greens with expanses of common heather, gorse, bell heather, cross-leaved heath and fescue grasses. And all with a scattering of purple knapweeds, orchids, violets and many more plants. All six British reptiles, from smooth snake to sand lizard, are found on it. There are butterflies, grasshoppers, bees and spiders galore. Half of our dragonfly species are found in wetter hollows. But such an environment is not easy to maintain.

Removing grazing, or stopping regular cutting, can have a huge impact on heathland plants. Two botanists, David Pearman and Andy Byfield, have documented such changes by re-recording the plants listed by Professor Ronald Good during surveys of Dorset's heathland in the 1930s.

They found that, of 41 rare heathland plants, all but three of them had declined by half or more. Yellow-flowered Petty Whin, for instance, had declined by 82 per cent; Myrsh Clubmoss, a primitive plant of wet hollows and Pale Dog-Violet, both declined by 88 per cent. Twelve plant species had disappeared altogether.

Some of these losses were the result of the heathland having been obliterated. But many were due to the abandonment of grazing or cutting, and to the loss of bare soil created by animals' hooves or old cart tracks. On the New Forest heaths, where grazing remains a traditional part of the land management, heathland plants have fared much better. Almost all still survive.

Protecting the best heaths with conservation designations is vital. Equally vital is managing them properly to retain their interest, whether this is done by private landowners and farmers receiving management payments through schemes such as Countryside Stewardship in England or directly by conservation bodies such as The National Trust. And, as in the Greenham Common case, recreating more heathland is possible, but at a price.

Wildlife sanctuary

Lowland heath is a cornucopia of plants and animals. But more than 80 of its species are conservation concerns. Under threat throughout its world range, the sand lizard - a small, yellow-and-black reptile - has disappeared from most of its former heathland strongholds. The demise and fragmentation of heathland, uncontrolled fires and scrub encroachment, have all done for it.

But a recovery programme, begun in 1994, is succeeding. Sand lizards have been reintroduced to five former sites where their populations are now monitored. The Action Plan - one of many recommended by the Government- appointed Steering Group - proposes their reintroduction to another 10 sites. Including research and monitoring, the cost of recovering the sand lizard is estimated at pounds 80,000 a year, declining to perhaps pounds 65,000 a year by 2010.

If the fortunes of the sand lizard are on the up, the fortunes of another heath dweller, the hoverfly - which, with its black and yellow stripes, mimics a wasp - are decidedly down.

Seemingly confined to the heaths of east Dorset, the New Forest and the Weald, it is declining dramatically. There have been just six sightings since 1980.

Halting its decline - leave alone reversing it - requires a knowledge of what's endangering it. But other than suspecting that the hoverfly's larvae are predators on particular aphids living in ant nests, very little is known about its needs.

Not surprising then, that the Action Plan stipulates more research on its lifestyle and more survey of past and present sites. Until this clever little mimic is better understood, conservationists can only assume that protecting more heathland, and managing its sympathetically, does the trick.

How to keep heathland healthy

If left to its own devices, heathland will disappear rapidly. Trees (pines and birch in particular) will quickly colonise it, growing into thickets, then converting it to woodland of a type which isn't as valuable for wildlife.

To guard against such natural encroachment, most trees have to be cut and removed if they have taken over. Light grazing, with sheep or cattle - ponies in some places - needs to be carried out to keep scrub in check. Different grazing densities in different places produce more habitat diversity and more wildlife.

Rhododendron and bracken, both of which can spread rapidly, need to be controlled by cutting or with safe chemicals. Patches of bare, sandy ground need to be created for certain species, such as Yellow Centaury, which is now very rare because its habitat is overgrown.