Urewera National Park
Officially announced on September 29, 1953 with an area of 49,000 hectares (122,500 acres)
Further additions have enlarged it to its current 213,000 hectares (532,500 acres), making it both the largest national park and the largest area of original native forest in the North Island. This is a remote, mountainous, very rugged land. Forest cover is almost total, and the tops of the two highest points (Manuhoa 1393 m/4570' and Maungapohatu 1366 m /4482') barely rise above the tree line. These forests are still inhabited by some of the most endangered native birds of New Zealand, such as kiwi, kokako, kaka and blue duck. Lakes Waikaremoana and Waikareiti are two major landforms born of the geological history of the park, and contribute greatly to its recreational attraction.Geological setting
Urewera National Park straddles the Huiau and Ikawhenua Ranges, in the east of the North Island between Bay of Plenty and Hawke's Bay. These ranges are part of the mountain axis of the North Island, which stretches over 650 km (404 miles) from Wellington to the East Cape. The main rock types in these mountains are the series of mostly sandstones and argillites of Triassic to Cretaceous ages generically referred to as greywacke, which form the north and western parts of the park. The southern and eastern parts, by contrast, are made of the younger (Tertiary) sandstones and siltstones of the Wairoa Basin. Their uplift has formed the higher ranges of the park (Panekiri, Ngamoko, Huiarau ranges), around Lake Waikaremoana, with a series of spectacular ridges and bluffs (Panekiri Bluff). A mantle of volcanic ash and pumice
In the last 20,000 years the whole area has been mantled by several layers of volcanic deposits, such as pumice and ashes, corresponding to eruption phases of the Taupo volcano. Apart from the steepest areas where they have been eliminated, these deposits are found throughout the park and may reach a thickness of 3 metres (10 ') in places.See also the Volcanoes of New Zealand
A fault-induced topography
The major ridges and river valleys of the park are parallel to each other, creating a distinctive topographical pattern that appears clearly on maps. The directions are north-north-east to south-south-west in the southern sector, and north-south in the northern sector. They correspond to a series of faults that are followed by rivers. These faults are related to the tectonic setting of the North Island axial ranges, which are compressed and uplifted under the strain generated by the subduction of the Pacific tectonic plate under the North Island. The fault that lies in the Whakatane River valley can be traced southwards more or less continuously to the Wellington Fault. Hot springs at Waiohau and in the upper Waiau catchments are a by-product of faulting of the earth's crust, where water can circulate quickly to great depths before coming back to the surface.
See also the Tectonics of New Zealand, and Active faults of New Zealand
Lakes and earthquakes
Lakes and rivers are, with the forest, the outstanding natural features of the Urewera National Park.Lake Waikaremoana, at an altitude of 580 m (1903'), was created about 2300 years ago when a wedge of sandstone and siltstone, nearly 3 km (1.86 miles) long, slid down from the south-western end of the Ngamoko Range, thus damming the Waikaretaheke River. The landslide was probably caused by an earthquake. Similar phenomena probably created Lake Waikareiti, which is located 300 m (984') higher and 4 km (2.5 miles) northeast of Lake Waikaremoana. Lake Waikareiti contains six islands and has no obvious outlet. It lies in a gently undulating basin densely forested with red and silver beech, beside areas of wetland and marshy clearings.Many waterfalls
There are many waterfalls in the rivers of the park, usually formed over sandstone sills after softer mud stones have been eroded away. Some, such as the Aniwaniwa, the Papakorito, the Mokau and the Hopuruahine, are located on the streams that flow into Lake Waikaremoana and are easily accessible. Many others can only be discovered while tramping further into the forest.Climatic conditions
The Urewera's wide range of land and altitudes results in equally diverse climatic conditions. The weather is generally milder north of the Huiau range, cooler and wetter south of it. The annual rainfall ranges for 1500 mm (59 in.) in the north to 3200 mm (126 in.) in the south, evenly spread throughout the year. In winter snow falls frequently on the summits of the southern ranges, but does not usually lie there for long.Vegetation
The forests of Urewera National Park are especially diverse. While variations depend on a number of factors such as soil type, rainfall and location, the prevalent influence is altitude. The general pattern in the park is of transition at 800 m (2625') from rimu/northern rata/tawa forest to beech/rimu forest. Above 900 m (2953') rimu disappears and the forest is dominated by one or several species of beech which extend up to the tops (these altitudes are approximate and may vary from place to place due to the large area of the park).Luxuriant lowland forests of the north
The lowland forests of the northern part of the park are characterized by kohekohe associated with tawa, pukatea and mangeao. In this zone rainfall is 1500-2000 mm (59-78 in.) per year, and the soils are developed on a layer of rhyolitic volcanic ash overlying the greywacke bedrock. Tall rimu and rata form a scattered upper layer, while the undergrowth is rich in species of tree ferns, nikau palms, vines, epiphytes, and many ferns.The lowland forest in the south-west of the park, the Waiau Valley in particular, are different from elsewhere in the park in that they contain high proportions of matai and totara. High altitude rainforests
Rainfall is highest in the eastern part (2000 mm/78 in. and more), corresponding to the highest altitudes, and the rhyolitic ash cover is thinnest. There are many swampy areas, where mountain cedars kaikawaka (Librocedrus plumosa) are found. On higher ground, above 1200 m (3937'), pure silver beech cover the crest of the ranges, their trunks and branches festooned by mosses, lichens and filmy ferns.Podocarp-rich pumiceous valley floors
Throughout the park the influence of soil is especially felt on the river terraces of the deepest valleys and gorges, where a general type of forest can be recognized. There the large podocarps - rimu, matai, totara and kahikatea - are more numerous than on the valley sides, and rata are absent. These trees appear to be more numerous where pumice is thickest. Other types of vegetation include limited subalpine scrub and montane mires with sedgeland, herbfields and aquatic plant communities. The south of the park is a stronghold for the wild populations of kowhai ngutukaka (kakabeak).Wildlife
Because of its large size and diversity of habitats, Urewera National Park supports a wide range of wildlife species, with at least 48 species of birds, and including some of the largest populations of several endangered species. A refuge for endangered birds
The largest surviving population of kokako is found in the north of the park. Other endangered birds include kiwi, red and yellow-crowned parakeets, kaka, New Zealand pigeon, New Zealand falcon, and blue duck. There have been unconfirmed sightings of the officially extinct bush wren and piopio. There are many other native birds in the forests, such as morepork, tui, bellbird, New Zealand pipit, fantail, whitehead, grey warbler, tomtit, North Island robin. Water birds include ducks, shags, gulls, kingfishers and the white-faced heron. Other wildlife include the native long and short-tailed bats, green gecko, skinks, a species of the large landsnail Powelliphanta, and native fish kukupa.
Introduced species
A range of introduced species also inhabit the park, including possums, deer, pigs, goats, cats, rats, dogs, mice and mustelids. While most of them threaten the indigenous fauna, flora or their habitats, the primary threats are possums, goats and deer. A high priority has been set for the control of goats and possums, with the highest priority being sustained possum control in the northern Urewera and at Manuhoa.