According to Bridgat, New Zealand is located in a temperate zone, so its climate is normally mild and humid and the differences between seasons are not very marked. The northern region has the warmest climate, while the south-western slopes of the New Zealand Alps are the coldest. Precipitation is generally moderate to abundant.
Some areas of New Zealand are more than 550 million years old. However, the country, as it is known today, was formed almost entirely during the last phase of mountain formation of the Tertiary period (about 26 million years ago). The islands are endowed with important chains of sedimentary rocks of marine origin. The oldest dates from the Cambrian period, although the rocks that make up 75% of present-day New Zealand began their formation during the Carboniferous period (about 315 million years ago).
New Zealand’s most important natural resource is its own land. More than half of the soil is suitable for cultivation and about a quarter is forested. Mineral deposits have been found on the main islands, but of all these only a few are of commercial value; the most significant are those of coal, gold, ferruginous sands and industrial minerals such as bentonite, pumice, limestone, clay, dolomite, quartz sands and gravel. In isolated blocks, uranium and thorium have been found, although it is possible that larger deposits of these minerals also exist.
New Zealand has rich energy resources; Apart from coal, it has a volcanic plateau that generates geothermal energy, and also has the considerable hydroelectric potential of the country’s rapids and the important natural gas deposits of the North Island, on its southwestern coast.
Flora and fauna
The isolation of New Zealand from other continents and the lateness of human settlements on the islands, have favored the development of a unique flora in the world. Of the 2,000 native species, about 1,500 are exclusive to the country; clear examples of this flora are the golden kowhai and the red pohutukawa.
The dominant vegetation of New Zealand was the mixed evergreen forest, which occurred especially in the warm North Island, in addition to thick undergrowth populated with mosses and ferns. The great exception is the prairie of the volcanic plateau on the North Island. Today, this dense forest or scrubland survives only in areas where passage is not allowed, in national parks and nature reserves.
On the western coast of the South Island, it contains one of the largest areas of native mixed forests, and also provides the largest amount of natural wood used for commercial purposes, such as kauri, rimu, kahikatea and totara. The lowlands of the South Island are currently grasslands that rise up to 1,525 m in altitude. Native false beech trees grow in the low latitudes of the New Zealand Alps, while alpine vegetation occurs in the higher areas.
Since 1900, a large number of exotic flora species have been introduced, specifically the rapidly growing and commercially important conifers, such as Douglas fir and California pine. The incorporation of some of these species has caused serious ecological problems; gorse has become a threat to native flora, as it proliferates rapidly, both through rich and poor terrain, at the expense of other species.
Contrary to the rich indigenous flora, New Zealand has few animal species of its own. When the first Maori settlement took place, New Zealand had two species of lizards: the gecko and the tuátara – a prehistoric residual species that maintains a third eye – several classes of frogs and two species of bats that are considered the only indigenous mammals.
Here there is a characteristic species of dog and black rat brought by the Maori, and today it is practically extinct. The current fauna of New Zealand includes the red deer, common rabbits, goats, pigs, weasels, ferrets and the Australian opossum; all descendants of the first species pointed out by the colonizers. Without the presence of predators, there are no snakes in New Zealand.
The autochthonous varieties are songbirds such as the bellbird and the tiu that, although incapable of flight, are the most associated with New Zealand. The moa-type ostrich, now extinct, was once the most numerous family of flightless birds. Kiwi is the best known of the current species, not to mention the kakapo, the takahe and the weka.
The country’s rivers host a great diversity of fish for domestic consumption, such as the chanquete, the eel, the lamprey and river crustaceans such as the crab. Trout and salmon are imported. Cold and warm currents converge in the surrounding ocean waters, which allows them to be rich in marine species. The warm currents bring in tuna, flying fish and marlin, as well as sharks attracted to local species such as snapper and trevally. On the other hand, cold currents bring blue cod, while hapuku and tarakihi are found along the entire coast. Among the seafood, oysters, mussels and toheroas stand out as edible varieties.