Forests of central New Zealand
The climate changes further south in New Zealand, and so do the forests. Temperatures are lower, and in the east it rains less. Species disappear from the conifer–broadleaf forests as they reach their limits of tolerance, and some hardier species enter in.
Tawa replaces taraire as the most common canopy tree in the southern two-thirds of the North Island, the Marlborough Sounds and the Seaward Kaikōura Range. Rimu and northern rātā are common as emergent trees in the moist western and central forests. Mataī and tōtara dominate in the drier forests to the east.
In the absence of beech forest, a hardier version of conifer–broadleaf forest grows at high altitudes.
In the North Island this is a relatively low forest dominated by kāmahi (Weinmannia racemosa), kāpuka (Griselinia littoralis), mountain tōtara (Podocarpus hallii) and the attractive conical mountain cedar (Libocedrus bidwillii).
In the South Island, southern rātā (Metrosideros umbellata) and Quintinia acutifolia are prevalent.
Large vines and epiphytes are uncommon. But, especially at highest altitudes, many smaller epiphytes – mosses, liverworts, filmy ferns and lichens – flourish in the cool, moist, misty climate. Every branch and twig is engulfed by these small organisms.
A kahikatea tree in South Westland holds the record for hosting the greatest number of plant species. Fifty species of epiphytes and climbers make their home upon the old conifer.
The far south
In the southern South Island and Stewart Island, most of the conifer–broadleaf forests are rimu growing above a canopy of kāmahi and southern rātā. Miro and mountain tōtara are also common conifers. Tree ferns, vines and epiphytes flourish in the wet climate.
Southland has high rainfall and many low-lying sites, so there is extensive swamp forest. As in northern swamp areas, kahikatea is abundant, but its northern associates, pukatea and swamp maire, do not grow this far south.
In the lower half of Stewart Island, yellow-silver pine (Lepidothamnus intermedius) is the dominant tree in swampy sites. It is a small tree and forms a low forest, 6–10 metres tall.