Where have all the woodlands gone?

Britain was once covered in trees. But today natural forests occupy a tiny proportion of our land area.

Robert Hod, fugitive, would not have credited it. The greenwood home of the legendary outlaw - better known today as Robin Hood - covers a mere 500 acres: not a large enough area in which to ambush the villainous Sheriff of Nottingham. In Robin's day, Sherwood - a mix of broadleaved forest and heath - was 20 miles long and eight wide, one of many huge forests in Britain.

The demise of Sherwood is, in microcosm, what has happened countrywide. After the last Ice Age, Britain was almost covered in woodland; mixed broadleaved forest in the lowlands; pine, birch and oak in the uplands; and alder on wetter land. Felling for timber, clearing land for farming and other development has reduced Britain's natural broadleaved woodlands to around 300,000 hectares - just 1 per cent of our land area.

Planted broadleaved woods - some with trees native to Britain, others not - cover an additional 2 per cent. Planted conifers, mostly using tree species such as spruces and pines from North America, take the total area under trees in Britain to around 10 per cent. Most European countries average 25-30 per cent.

Woodland is not simply a collection of trees. Natural woods - such as the hillside oakwoods of Snowdonia and the beechwoods of the Chilterns - are home to a cornucopia of plants and animals. Planted woods, especially those comprising trees not native to Britain, can't compete.

On acid soils, birch, oak and rowan often dominate our native woods, with hazel and holly in the understorey. On more rich, alkaline soils, ash often dominates with wych elm, wild cherry, hornbeam and field maple. Yew woods are the only native conifer-dominated woodland south of Scotland.

The trees themselves provide a habitat for lichens, mosses, liverworts and even some ferns to grow on. A ground layer of grasses, ferns, and flowers including, in many woods, a springtime flower show of bluebells, wood anenomes and wood sorrel, is typical of most lowland woods. In the wetter west and north of Britain, a plethora of mosses, some of them rare, can carpet boulders and tree boles.

Add to this the huge number of invertebrates - from ants to bees and butterflies - and woodland birds including a plethora of warblers and tree specialists such as woodpeckers, and it isn't surprising that native broadleaved woods are our richest habitats.

According to the panel of experts comprising the UK Steering Group on biodiversity, 46 woodland species, mostly invertebrates and plants, have become extinct over the last century, while a further 78 are in rapid decline. Considering that our native woodland is now a remnant of what there once was, it's surprising, perhaps, that we haven't lost more.

While many of our woods are simply left as nature intended, others have a long history of management which has altered their structure, their wildlife, even the trees which stand sentinel within. Stour Wood in Essex, owned by the Woodland Trust but managed by the RSPB, is a good example. "It's a sweet chestnut coppice with some trees cut down to their stumps every 15 or 20 years to encourage the growth of slender, dense poles," says the warden, Russell Leavett. "Other chestnuts are allowed to grow to their full height."

Historically the poles were used to make fencing and sheep hurdles while the large timber was used to build ships. It's an ancient practice to which the wood's wildlife has been adapted for centuries. So the RSPB reintroduced Stour Wood's traditional management, starting again in 1984 after a 12-year gap.

"In 1983 there were only nine pairs of warblers in the wood," says Mr Leavett. "By 1994 there were 69 pairs - and nightingales have increased from none to four pairs." Butterflies, such as the white admiral - here in its only Essex location - and other insects have also benefitted.

In other parts of Britain woods are over used. In the upland areas of Wales, for instance, oak woods are often grazed by sheep, preventing young trees from growing up, and eliminating many of the forest shrubs.

But the trend is being reversed. Coed Cymru - a partnership of Forest Authority, Countryside Council for Wales, Local Authorities and Farming Unions - has brought 7,000 hectares of Welsh woods into management since 1985. Fencing to prevent livestock access has been a priority as is the creation of markets for Welsh wood products so that farmers have an incentive to look after their woods and manage them sustainably.

In other parts of Britain similar initiatives, both to manage existing woodlands and to plant new ones, are underway. Grants for tree planting and for the rehabilitation of existing woodland are available throughout Britain from the government's Forest Authority.

Many new woods - albeit on a small scale to begin with - are being planted near towns and cities, an initiative which will, hopefully, increase public understanding of the wonders a woodland has on offer. The Woodland Trust, recently awarded over pounds 6 million from the Millenium Commission for its Woods on your Doorstep project, has been seeking suggestions for sites to plant its first 200 new woods.

Austin Brady, Project Director for the Sherwood Forest initiative, is keen on expansion, too. "We might be able to buy land if our fund raising is successful enough but we will also help local communities nearby to plant trees," he says.

Mr Brady's problem is that the vegetable and crop growing land around Sherwood is valued at up to pounds 6,000 a hectare, financially virtually out of reach for tree planting. Nearby derelict land from coal mining might be more practical. And some conifer plantations around will slowly be converted back to broadleaved forest. Very slowly, because planted trees may take centuries before they develop the richness of wildlife a natural forest possesses, Britain is regaining some of its long lost wooded landscapes.

Life after death

In a natural forest, nearly half the timber is in various stages of decomposition. Standing dead trees, fallen branches and rotting stumps are all home to an enormous array of fungi and wood boring insects. Ironically, dead wood in a forest is its richest wildlife habitat.

A fifth of our insects survive only on dead wood. This army of little rotters includes wasp-mimicking flies, longhorn beetles, click beetles, hornets, robber flies and weevils. Meanwhile, hundreds of colourful fungi devour nothing other than dead wood. White, fan-shaped funnels of Angels Wings grow on rotting conifers, while the yellow-brown gregarious elf cap prefers oak stumps.

But forest life from the dead isn't what it was. Foresters have been obsessed with tidiness, so dying trees and fallen branches are removed. The rotters are dying out as a result. "Around 40 per cent of wood-rotting insect species are threatened with extinction Europe-wide," says Dr Martin Speight, an expert on them.

The large, metallic bronze hoverfly, Callicera spinolae, is one such casualty. Now rare Europe-wide, it was once found in at least seven East Anglian woods. Other creatures are also suffering. Many forest birds - from warblers to woodpeckers - feed on insects, including wood-rotting ones. Slowly decaying old trees, now in short supply, provide roost holes for owls and for greater horseshoe bats, one of several species of bat in decline.

According to Dr Speight, protecting existing forests containing old trees and dead wood is a priority but woodland management attitudes everywhere need to change so that dead timber is viewed as an asset and not as a nuisance.

Return of the Scottish pinewood

A few thousand years ago, Scots Pine forests clothed perhaps 1.5 million hectares of the Scottish Highlands. Today a paltry 16,000 hectares survive in widely scattered fragments. Even some of these are not guaranteed to survive. They are grazed by red deer or sheep, preventing young trees from growing up to provide the forest of the future.

Scots Pine forests can be magical places. Thickets of shrubs (including juniper, blueberry and crowberry) with taller aspen and holly cover the craggy ground between the tall pines, birches and rowans.

The only bird species confined to Britain - the Scottish crossbill - is a pine-wood specialist. Around 1,500 of these colourful birds (the male is red) survive. This is the haunt, too, of the capercaillie, a goose- sized grouse. It is declining in numbers for a wide variety of reasons which may include disturbance and changes in vegetation caused by too much grazing. Just over two thousand capers grace these northern forests.

Among the rare pine-wood plants is the twinflower, with its pairs of blushed pink flowers. Scottish Natural Heritage hopes to grow it from seed and then restore it successfully to pinewoods from which it has been lost.

Felling of native pine-woods is banned. Advice and grants are available from the Forestry Authority for planting new Scots pine-woods and for fencing existing ones to allow them to regenerate by keeping deer and sheep at bay. An Action Plan which involves protecting and maintaining their remaining 16,000 hectares, and regenerating and planting a further 36,000 hectares over the next couple of decades, at a cost of around pounds 250,000 a year has been put to government.