I HAVE received a note from the RAC Motoring Services to remind me that only five trees planted in a year can offset the emissions which come from the average annual mileage of a family car.

The foliage of the trees absorbs the carbon dioxide discharges and turn it into oxygen which is vital to the survival of this planet. This is only one reason why trees are such a vital part of our heritage.

To encourage the planting of trees, the RAC and Future Forests are working together in a special offer by which they will plant five trees for the price of four, and there will also be a Future Forest Christmas card which can be sent to friends telling them where your own tree has been planted. The total cost is £6 per tree (£5 to plant the tree and £1 for the card and postage), and the offer is available until the end of November. Further information can be obtained on the RAC web site at www.rac.co.uk or by telephoning 0870 3214149.

National emblem

At this time of year, many of the trees in our countryside, parks and gardens are adorned in the finest of their autumn colours. Although some may have lost their foliage, others are in their prime so far as the end-of-season display is concerned but it takes only a handful of hard frosts and a few blasts of wintry wind to strip away the lingering leaves.

This year, some trees seem to have clung to their foliage for much longer than normal, perhaps due to the very mild October, but the onset of winter is inevitable and soon all our deciduous trees and some conifers will look bare.

Prominent among them will be the oak, always recognised very easily due to its distinctive rugged shape and the irregular and sometimes twisted pattern of its branches. There is a sturdiness to its stark outline; its trunk is strong and wide, its branches extend to cover a large area and it seems to dominate any woodland clearing or hedgerow like a guardian or stern father might stand out in a crowd.

Not without reason, the oak is seen as akin to a national emblem. If there is one tree which can be identified as essentially English, then it is surely the oak and in many ways it has helped to shape our history. Down the centuries, the durability and toughness of its timber has endured in many ancient buildings where it has supported the roofs of churches and castles, mansions and cottages as well as forming the hard-working floors. So hard is the wood that it will survive for century after century and it will even defy nails; some of the woodwork of the early half-timbered houses was held together with pegs because nails were useless.

Shipbuilding also benefited from our native oak trees, and the destruction of our former oak forests was due to the demand for this wood, especially during the 17th and 18th centuries. It required some 3,000 mature oaks to construct just one man-o'-war but, in addition, oak was used for making the keel, frame and ribs of almost every other kind of wooden sailing vessel. Even the Vikings used oak and it is still used in the construction of some modern wooden boats.

Furniture is another product of the oak, both in churches, offices and in our homes and it appears under all manner of guises where strong and reliable timber is required. I'm told, too, that it is impervious to alcohol, therefore finding use in the manufacture of barrels for beers and wines. It is a handsome timber and its colour can vary greatly, often due to fungi which attack the living tree, while on occasions it can reveal beautiful patterns deep within the wood.

While the oak can be regarded as almost essential to our nation's well-being, then in its wild condition it also provides shelter and accommodation for a host of creatures and plants. One reason is the fruit of the oak, the acorn. This is loved by a variety of birds and animals - pheasants are known to consume acorns and some years ago I heard of one pheasant which choked to death through eating one, although it had tried to swallow the cup as well as the fruit. In the New Forest, pigs used to be turned out to feed on fallen acorns; this was known as the pannage season, while squirrels both red and grey lose no opportunity in storing acorns for future use, even if they sometimes forget where they've put them.

If creatures of this kind are attracted to the oak because of the acorn crop, then so is the acorn weevil, a type of beetle which lays a single egg in an acorn. When this hatches, the grub eats the flesh of the acorn, emerging when the acorn falls to the ground. Many insects infest the deep crevices in the bark of an oak and so attract birds such as woodpeckers and tree-creepers, but among the insects which haunt the oak are gall wasps whose presence produces a variety of effects. The most obvious is a hard rounded ball-like growth, about the size of a cherry, known as an oak apple.

Because it appears among the leaves, one can be tempted into thinking this is the fruit of the oak but it is not; it is the home of the eggs of a type of gall wasp. In time, they burrow their way out of the oak apple and their former presence is often revealed by a tiny hole in the brown outer skin.

Because the spreading of the oak branches provides a light shelter upon the floor of the woodland, this encourages a host of plants whose life is enhanced by the fallen leaves as they produce compost. In turn, these plants encourage small mammals to live among them, such as voles, shrews and rabbits, and their presence attracts predators such as foxes, owls and birds of prey.

With such an array of wildlife, and with such a variety of uses for the human race, it is not surprising we refer to the oak as "monarch of the forest", and that our pagan forebears regarded it as a sacred plant. Many believed the oak protected them against thunder and lightning and in some parts of the country, weddings were performed beneath the oak. Not surprisingly, acorns were also thought to possess magical powers and so women carried them in the belief they would enjoy perpetual youth.

Mouthwatering

Our recent trip to the Lake District, whose residents were still reeling from the effects of foot-and-mouth disease, made me appreciate the range of locally produced foods which were on sale. Local and speciality shops offered a range of bottled fruits and confections both sweet and savoury, in addition to drinks and cheeses, meats and meat dishes and other products like pies and cakes.

In every case, these were made locally and were sold in small shops in the villages. Without doubt, the quality was very high indeed and the products were beautifully packaged and presented for sale. Other outings have revealed a similar choice in the Yorkshire dales, the North York moors, Durham and Northumberland.

Upon my return, therefore, I was not too surprised to find a note from the Council for the Protection of Rural England which stated that sustainable local foods were the key to rural recovery. The CPRE highlighted a range of foods, such as distinctive local apple varieties, meat which was reared locally and speciality farmhouse cheeses, and it expressed its belief that such products could help to remove the alienation which had arisen from the way some provisions were grown and processed.

I was surprised to learn that the local and speciality food and drink sector, excluding organics, is contributing £3.7bn per year to the economy, and that turnover in 73pc of these businesses is increasing. More than 70pc of these businesses are located in rural areas and that fact must be valuable to the future of rural Britain.

Among the methods of sale highlighted by the CPRE are farmers' markets, now becoming increasingly popular. The CPRE reports that the Health Development Agency has said that farmers' markets offer good value for money; provide an opportunity to buy fresh local produce; give local people a sense of well-being and belonging; provide a social meeting place and also play a role in revitalising the local rural economy