What was the original forest composition of Great Island (Three Kings)?

Abstract

Following the extermination of goats (Capra bircus) from Great Island in 1946 the recovery of that island's vegetation has been of tremendous scientific interest. Numerous papers have been written on the subject and recent visits to Great Island by the Northland Conservancy have continued to document changes in forest structure. Since 1989 it is becoming evident that in many places the monotonous and extremely dense kanuka (Kunzea ericoides s.l.) canopy is starting to collapse, presumably due to the combined affects of old age and exposure to the often stormy maritime climate. Of interest is what the new forest structure will be. While in places the canopy and understorey is now dotted with rapidly growing specimens of porokaiwhiri (Hedycarya arborea), mangeao (Litsea calicaris) (Cameron et al. 1987; P.]. de Lange pers. obs.) and albeit less frequently, titoki (Alectryon excelsus var. grandis), the spread of these trees is being hampered by a lack of natural seed dispersers. Therefore many patches of forest either lack an understorey or have a forest composition comprising short-lived smaller trees such as pukanui (Meryta sinclairii), cabbage tree (Cordyline kaspar), Three Kings rangiora (Brachyglottis arborescens) or shorter stature trees (really large shrubs) e.g. Fairchild's kohuhu (Pittosporum fairchildii) and Oliver's mapou (Myrsine oliverii).