This web map service shows estimates of stock (length) of linear features across Great Britain in 2007, 1998, 1990 and 1984. The data are national estimates generated by analysing the sample data from 1km squares surveyed for the Countryside Survey in each of those years, then scaling up to a national level. The data are presented as the estimated mean length of linear features (hedgerows, walls, fences, banks, grass strips and tree lines) per 1km square within 45 different Land Class types based on the ITE Land Classification. The Countryside Survey is a unique study or 'audit' of the natural resources of the UK's countryside, carried out by the Centre for Ecology & Hydrology. The sample sites are chosen from a stratified random sample, based on a 15 by 15 km grid of GB. Surveys have been carried out in 1978, 1984, 1990, 1998 and 2007 with repeated visits to the majority of squares. The countryside is sampled and surveyed using rigorous scientific methods, allowing us to compare new results with those from previous surveys. In this way we can detect the gradual and subtle changes that occur in the UK's countryside over time. In addition to linear features, habitat areas, species plot, soil plot, freshwater habitat and satellite map data are also produced by Countryside Survey.