This series of datasets consists of mean estimate distribution maps of ash trees (Fraxinus excelsior) across Great Britain. It includes ash trees in areas less than half a hectare, ash trees in woody linear features and individual ash trees. The data are derived from Countryside Survey 2007. Trees were mapped in 569 1km sample squares across Britain using a stratified random sampling system based on the ITE Land Classification. Mean national estimates were produced by scaling up from the sample data.