This BioProvince include New Zealand (North and South islands), Stewart Island and a multitude of smaller islands. It experiences an extreme maritime climate especially on the west coast, which lies directly in the path of the moisture-laden west winds. In the lowlands, rainfall varies from about 350 mm per year in rain-shadow of the Southern Alps in Central Otago to about 6000 mm per year in Milford Sound, but high on the flanks of the Southern Alps above Whataroa is one of the wettest places on Earth with an enormous 15,000 mm per year. In terms of latitude the climate ranges from subtopical in the north to subantarctic in the south. New Zealand is sometimes referred to as the ‘ancient island’ because of the antiquity of its plants, freshwater fish, amphibians, repiles and birds, many of which were inhabitants of the ancient supercontinent of Gondwana. It drifted south away from Gondwana some 80 million years ago in the late Cretaceous period during the latter part of the age of the dinosaurs. The fossil record shows that certain dinosaurs survived for a while on the breakaway landmass. Other life forms such as land mammals, snakes and many flowering plants are not present simple because they had not evolved at the time of the breakup. New Zealand’s forests are thought to be very close to the ancestral forest of Gondwana and they are still the preferred habitat of many of the lower animals of Gondwanan lineage. The flora comprises some 47 endemic genera and about 2000 endemic species. One of the most impressive features of the flora is the diversity of alpine plants. About 600 higher plants (25% of the total flora) are found above the tree line, and of these, 93% are endemic. But it is the shear diversity of plant forms that is so remarkable ranging from the smallest pine in the world, the endemic pygmy pine Lepidothamnus laxifolius (Podocarpaceae) to the largest moss in the world, the endemic Dawsonia superba (Dawsoniaceae). This BioProvince was divided into three bioprovinces by Armen Takhtajan but because they have a number of features in common they are here regarded as sub-bioprovinces. They include the Northern Neozeylandic Sub-BioProvince, the Central Neozeylandic Sub-BioProvince, and the Southern Neozeylandic Sub-BioProvince.
The Northern Sub-BioProvince includes New Zealand’s North Island roughly north of a line between the Mokau River in the west and Tauranga in the east. It also includes the Three King’s Islands north of Northland and all the islands on the east coast. Despite being mainly represented by Malesian elements, especially regarding the ferns, the flora is classed as sub-tropical. There is a small Australian element especially evident in the orchids and sedges, but other taxa characteristic of Australia are largely absent. The flora has a high degree of endemism with three monspecific genera (Elingamita, Ixerba and Loxsoma) and numerous endemic species.
The Central Sub-BioProvince comprises the southern part of New Zealand’s North Island south of the Northern Neozeylandic BioProvince, and the northern part of South Island to a line connecting Greymouth on the east coast to Auri Bluff. Also included are the associated islands such as Kapili Island. The flora has two endemic genera (Chordospartium and Pachystegia) and many endemic species.
The Southern Sub-BioProvince comprises the southern part of New Zealand’s South Island south of the Central Neozeylandic BioProvince. It also includes Stewart Island and other associated islands such as Ruapuke Island and Solander Island.
The following accounts for this BioProvince have been written or will be written with particular reference to endemic and locally important species. Accounts available are displayed in green or yellow. Those displayed in red are either in the pipeline or awaiting expert contributions.
|Endemic Vascular Plant Flora|