Evergreens such as the giant kauri and southern beech dominate the forests. Prehistoric kauri forests have been preserved in waterlogged soils as swamp kauri. Copal, kauri gum, dammar and other resins may also be found as subfossil deposits. Early industry included logging of kauri and other timbers, flour milling and boat-building. The largest area of mature kauri forest is Waipoua Forest in Northland. Loggers then moved in to fell the kauri and other timber. Extraction of ancient swamp Kauri (Agathis australis), is a contentious industry . Kauri forests are among the most ancient in the world. Despite being logged the kauri pines dominate in some areas. Like many ancient kauri both trees were partly hollow. In the Agathiphagidae, larvae live inside kauri pines and feed on seeds. When young, are generally very spindly, and are common in young kauri forests. Dalmatian migrants were particularly prominent in the kauri gum extraction. The long, straight hardwood from the kauri was ideal for ship masts and spars. It possesses the mottled, shedding bark that is characteristic of other kauri species.