North Island temperate forests
The North Island temperate forests, also known as the Northland temperate forests, is a temperate broadleaf and mixed forests ecoregion on New Zealand’s North Island.
Geography
The ecoregion has an area of, which covers most of the North Island. The ecoregion extends from sea level to high volcanic peaks. The northern portion of the island, including the Northland Peninsula, Coromandel Peninsula, and the lowland region around Hamilton, are part of the separate Northland temperate kauri forests ecoregion.The North Island Volcanic Plateau occupies the center of the island. Lake Taupō, New Zealand's largest lake, sits in a volcanic caldera formed during a violent eruption 2000 years ago. The volcanic peaks of Mount Tongariro, Mount Ngauruhoe, and Mount Ruapehu lie south of Lake Taupō. Much of the plateau is covered lava fields, volcanic mudflows, and deposits of volcanic ash.
Mount Taranaki is an active volcano, which lies on the west of the volcanic plateau near the island's west coast.
A belt of folded mountains, which includes the Tararua Range and the Kaimanawa Range, runs parallel to the east coast from Wellington at the southern tip of the island to East Cape in the northeast. These mountains are predominantly of sedimentary greywacke, in contrast to the igneous rocks of the volcanic plateau. There are coastal lowlands along the eastern, western, and northern shores of the island.
Flora
In the lowland forests, emergent podocarps rimu and mataī rise above a canopy of evergreen broadleaf trees that includes kamahi and tawa.Middle-elevation forests on the volcanic plateau are dominated by podocarps, including rimu, miro, mataī, tōtara and kahikatea. Middle elevation forests on Mount Taranaki include Hall's totara and kaikawaka.
Higher-elevation plant communities include southern beech forests and tussock grasslands. Shrublands of leatherwoods, including Olearia colensoi and Brachyglottis rotundifolia are common at the treeline, with tough leaves that resist water loss from the mountain winds. Alpine communities, principally tussock grasslands, occur above the treeline.
Fauna
The ecoregion is home to several threatened native species, including the North Island brown kiwi, lesser short-tailed bat, and North Island kōkako. Native reptiles include Whitaker's skink, forest gecko, and Wellington green gecko.Conservation and threats
Most of the ecoregion's original forest is gone. In the lowlands it has mostly been replaced by agriculture, and on the plateau by pastureland and extensive plantations of exotic timber trees, principally radiata pine introduced from California in the 19th century.Prior to human settlement of New Zealand, birds were the largest land animals, and the only land mammals were bats. The ecoregion was home to several species of flightless moa, Haast's eagle, the flightless New Zealand swan and the North Island goose. The Māori arrived around 1280, and are the first known humans to inhabit New Zealand. The early settlers hunted many of the large birds, including the moas, native swan, and native goose, to extinction. They brought with them the Polynesian rat. Europeans settled in the 19th century, and brought with them the black rat, domestic cat, Norway rat, and stoat. These introduced predators took a heavy toll on the native birds and insects, some of which survive only or mainly on offshore islands free from exotic predators. Introduced goats and Common brushtail possums heavily browse the lowland forests, and possums have decimated kamahi and rata in lowland forests and kaikawaka and Hall’s totara in the southern ranges.