Woodland provided the primary building material. Woods were also a source of wood, fuel, timber and forage for pigs. In southern England, hazel was particularly important for coppicing, the branches being used for wattle and daub in buildings. Saxon woods were often surrounded by a bank and ditch, to mark boundaries. The bank often supported a fence of hawthorn or blackthorn to prevent livestock or deer entering, attracted by young shoots on coppice stools.