Trees and woodlands are an integral part of Britain’s heritage and culture. From pictures of kings hunting in leafy forests to the works of Thomas Hardy with their detailed descriptions of the lives of woodland occupants they are a part of our landscape which is often taken for granted (Plate 1.1). This is perhaps not surprising; our ancestors relied on wood to keep them warm, to provide fuel for cooking, as timber for building houses and ships and to make a myriad of other products which today we are no longer familiar with. Even now, the products of trees are central to our lives. The quantity of paper and packaging everyone uses is substantial and, although houses are no longer built solely from wood, it is still widely used in construction as well as in furniture and fittings.