The Countryside Survey (CS) of Great Britain consists of an extensive set of repeated ecological measurements at a national scale, covering a time span of 29 years. CS was first undertaken in 1978 to monitor ecological and land use change in Britain using standardised procedures for recording ecological data from representative 1 km squares throughout the country. The vegetation component has subsequently been repeated in 1990, 1998 and 2007, and changes may be related to a range of drivers.