New Zealand

Geography and Environment

New Zealand comprises two main islands, the North and South Islands, Te Ika a Maui and Te Wai Pounamu respectively in Maori, and a number of smaller islands, located near the centre of the water hemisphere. Cook Strait, 20 kilometres wide at its narrowest point, separates the North and South Islands. The total land area, 268,021 square kilometres (103,483 sq mi), is a little less than that of Italy or Japan, and a little more than the United Kingdom. The country extends more than 1600 km (1000 mi) along its main, north-north-east axis, with approximately 15,134 km (9,404 mi) of coastline. The most significant of the smaller inhabited islands include Stewart Island/Rakiura; Waiheke Island, in Auckland's Hauraki Gulf; Great Barrier Island, east of the Hauraki Gulf; and the Chatham Islands, named Rekohu by Moriori. The country has extensive marine resources, with the seventh-largest Exclusive Economic Zone in the world, covering over four million square kilometres (1.5 million square miles), more than 15 times its land area.

The South Island is the largest land mass of New Zealand, and is divided along its length by the Southern Alps, the highest peak of which is Aoraki/Mount Cook at 3754 metres (12,320 ft). There are 18 peaks over 3000 metres (9843 ft) in the South Island. The North Island is less mountainous but is marked by volcanism. The highest North Island mountain, Mount Ruapehu (2797 m, 9177 ft), is an active cone volcano. The dramatic and varied landscape of New Zealand has made it a popular location for the production of television programmes and films, including the Lord of the Rings trilogy and the The Last Samurai.

The country owes its varied topography, and perhaps even its emergence above the waves, to the dynamic boundary it straddles between the Pacific and Indo-Australian Plates. New Zealand is part of Zealandia, a continent nearly half the size of Australia that is otherwise almost completely submerged. About 25 million years ago, a shift in plate tectonic movements began to pull Zealandia apart forcefully, with this now being most evident along the Alpine Fault and in the highly active Taupo volcanic zone. The tectonic boundary continues as subduction zones east of the North Island along the Hikurangi Trench to continue north of New Zealand along the Kermadec Trench and the Tonga Trench which is mirrored in the south by the Puysegur Trench.

New Zealand is culturally and linguistically part of Polynesia, and is the south-western anchor of the Polynesian Triangle.

The latitude of New Zealand, from approximately 34 to 47° S, corresponds closely to that of Italy in the Northern Hemisphere. However, its isolation from continental influences and exposure to cold southerly winds and ocean currents give the climate a much milder character. The climate throughout the country is mild and temperate, mainly maritime, with temperatures rarely falling below 0 °C (32 °F) or rising above 30 °C (86 °F) in populated areas. Historical maxima and minima are 42.4 °C (108.3 °F) in Rangiora, Canterbury and −21.6 °C (−6.9 °F) in Ophir, Otago. Conditions vary sharply across regions from extremely wet on the West Coast of the South Island to semi-arid (Köppen BSh) in the Mackenzie Basin of inland Canterbury and subtropical in Northland. Of the main cities, Christchurch is the driest, receiving only 640 mm (25 in) of rain per year; Auckland, the wettest, receives almost twice that amount. Auckland, Wellington and Christchurch all receive a yearly average in excess of 2000 hours of sunshine. The southern and south-western parts of South Island have a cooler and cloudier climate, with around 1400–1600 hours; the northern and north-eastern parts of the South Island are the sunniest areas of the country and receive approximately 2400–2500 hours.

Biodiversity

Because of its long isolation from the rest of the world and its island biogeography, New Zealand has extraordinary flora and fauna, descended from Gondwanan wildlife or since arriving by flying, swimming or being carried across the sea. About 80% of New Zealand's flora is endemic, including 65 endemic genera. The two main types of forest are those dominated by podocarps and/or the giant kauri, and in cooler climates the southern beech. The remaining vegetation types in New Zealand are grasslands of tussock and other grasses, usually in sub-alpine areas, and the low shrublands between grasslands and forests.

Until the arrival of humans, 80% of the land was forested. Until 2006 it was thought that there were no non-marine native mammals, barring three species of bat (one now extinct). However in 2006 scientists discovered bones that belonged to a long-extinct unique, mouse-sized land animal in the Otago region of the South Island. A diverse range of megafauna inhabited New Zealand's forests, including the flightless moas (now extinct), four species of kiwi, the kakapo and the takahe, all endangered by human actions. Unique birds capable of flight included the Haast's eagle, which was the world's largest bird of prey (now extinct), and the large kaka and kea parrots. Reptiles present in New Zealand include skinks, geckos and living fossil tuatara. There are four endemic species of primitive frogs. There are no snakes and there is only one venomous spider, the katipo, which is rare and restricted to coastal regions. There are many endemic species of insect, including the weta, one species of which may grow as large as a house mouse and is the heaviest insect in the world.

New Zealand has suffered a high rate of extinctions, including the moa, the huia, laughing owl and flightless wrens (which occupied the roles elsewhere occupied by mice). This is due to human activities such as hunting, and pressure from introduced feral animals, such as weasels, stoats, cats, goats, deer and brushtailed possums. Five indigenous vascular plant species are now believed to be extinct, including Adam's mistletoe and a species of forget-me-not.

New Zealand has led the world in island restoration projects, where offshore islands are cleared of introduced mammalian pests and native species are reintroduced. Several islands, including two of the Chatham Islands, are wildlife reserves where common pests such as possums and rodents have been eradicated to allow the reintroduction of endangered species to the islands. A more recent development is the mainland ecological island.

Source: Wikipedia