Often described as ‘the winterless north’, Northland enjoys some of the highest mean annual temperatures in the country, although like everywhere in New Zealand the weather can be erratic. Typical maximum summer daytime temperatures range from 22°C to 26°C, but seldom exceed 30°C. Average winter maximum temperatures are between 14°C and 17°C. Summers are warm and humid, while winters are mild with only a few light frosts in sheltered areas.
The prevailing wind is from the south-west, but in summer the remnants of tropical cyclones occasionally bring gusty north-easterly winds and heavy rainfall. On lowland areas mean annual rainfall ranges from 1,200 to 1,700 millimetres. On higher country it can be as much as 2,500 millimetres. Winter is the wettest season. The temperate, moist climate sustains a favourable habitat for plants and animals.
Trees and plants
Over the centuries Northland’s natural life has been greatly modified by human habitation. The region was once covered in native forest and gumland scrub. The latter, characterised by mānuka, sedges and tangle fern, emerged after pre-European fires. Indigenous forest now covers only about 14% of the region. These forests contain some giant kauri trees that survived the extensive milling activities of the 19th and early 20th centuries, but in the 2010s were threatened by Kauri dieback, a phenomenon exacerbated by a plant pathogen.
On the west coast north of Dargaville are found the Waipoua Forest, a major conservation reserve, and the smaller Trounson Kauri Park. Puketī in the Bay of Islands hinterland is perhaps the most accessible of the more than 30 native forest reserves in the region.
Some 6% of New Zealand’s native plants are unique to the north – the forest reserves contain 125 species not found elsewhere. In summer the coasts blaze with the deep red of the flowering pōhutukawa, native to the north and sometimes called New Zealand’s Christmas tree. The harbours have extensive mangrove forests, which are expanding in some places. Groves of pūriri trees are often seen on farmland.
The pūriri trees are laughing
In the 18th century the dominant Ngāpuhi tribe evicted the people of Ngāti Pou from the Taiāmai plains. The displaced people saw the fires Ngāpuhi had made with pūriri wood and heard the burning trees splutter in a mocking way. The whakataukī (saying), ‘Ka kata ngā pūriri o Taiāmai’ (the pūriri trees of Taiāmai are laughing) expressed their sadness at losing their homeland.
The forests are home to the Northland green gecko, two rare bat species, three species of flax snail and the carnivorous kauri snail, significant populations of the North Island brown kiwi, kererū (New Zealand pigeon), North Island kōkako and Hochstetter’s frog. There are also small numbers of other threatened species, such as the native parrots, kākā and kākāriki.
Coastal areas and wetlands provide a habitat for the New Zealand dotterel, the variable oystercatcher, the brown teal, the fairy tern, and migratory wading birds. The survival of many of these species is at risk, due to activities such as forest clearance, coastal development and drainage (most of the original wetlands have been lost through drainage works), and because of introduced predators. Northland has some predator-free islands on which tuatara and some skinks, geckos, forest birds and seabirds that are not present on the mainland still survive.
Possums, feral deer and goats severely damage native forests and threaten the kiwi population, as do dogs. Along with hares and rabbits, they damage horticultural crops and farmland. Weasels, stoats, ferrets, possums and wild cats threaten the native wildlife populations. Wild ginger has been a problem in forest areas.
Pest control is carried out by local authorities, landholders and the Department of Conservation. In the early 2000s, some 20,000 possums were eradicated from the Waimate North district in three years by private landowners.