Giant Kauri, Tane Mahuta
The Kauri - Kauri Forest Map - Plant Nursery
This significant conservation project aims to regenerate New Zealand's ancient kauri forest in its heartland of Waipoua. The Waipoua Forest is the largest remaining kauri forest in the world. We are revegetating surrounding farmland and scrub with native trees, from manuka, Leptospermum scoparium, a colonising species, through to kauri, the dominant canopy species in this type of forest.
Work so far has concentrated on three areas:
The Kauri, Agathis australis, is one of a genus of over 20 very large trees occurring in Malaysia, Indonesia, Melanesian islands, Australia and New Zealand. It is the only non-tropical species and is found only in northern New Zealand. The kauri is the world's largest rainforest tree! It shares a family with its more-distant relatives of the genus Araucaria, which includes Chilean Pine (monkey-puzzle tree), Hoop Pine and Norfolk Island Pine.
Kauri forest is subtropical or warm-temperate rainforest, and like all rainforests supports a very diverse flora and fauna, some of which are pictured in our Images section. Like many rainforests, kauri forest thrives on poor soils which, if cleared, may be of little use for agriculture.
Kauri was so heavily exploited in 19th and early 20th century that only 1% of the original old-growth kauri forest survives today.
New Zealand's lowland forests have all been saved by public campaigns. Waipoua Forest was New Zealand's first forest preservation campaign, which was led by Professor W R McGregor in the late 1940s. The present sanctuary of about 9000 hectares was legally protected in 1952. Protection of the Waipoua ecosystem is not yet complete, however. For kauri to survive in the long term, it needs large areas across varied landscapes, so we must restore its fragmented boundaries, connect it to the coast and protect it from introduced pests.
The wind-blown seed of a kauri lands on bare ground, mossy forest floor or an ancient tree stump. In the shelter of the forest, it establishes in its characteristic seedling form. Decades later, it emerges through the forest (or manuka) canopy as a cone-shaped tree called a ricker. 100 or so years later, it develops a spreading crown which continues to expand for the next 500 years or more.
As the kauri ages, its trunk steadily increases in girth. It may live 1000 years or more - on good sites, exceptional specimens can live for more than 3000 years. Old age is a slow process for a kauri. While limbs break off in storms, and the centre of the tree hollows out, the tree's trunk continues to expand. Inevitably the time comes when the tree dies, or falls in a cyclone. This creates the habitat for a new generation of kauri. The gap in the canopy provides sunlight, and decaying tree remains provide a long-term supply of nutrients for the young kauri.
Kauri is a tree of the forest. Exposed kauri - for example on a forest edge or roadside, like these shown here flanking State Highway 12 - easily suffer weather or root damage. The left-hand tree in the picture is dying - eventually leading to the loss of a notable view, but also an opportunity to widen the road.
Kauri often grows in dense groves, the trees growing closer together than might be thought possible. This group of four is close to the road and easily accessible to visitors.
The trunk of the kauri has a striking "hammer-marked" pattern, caused by the bark falling off in large flakes. This gives the tree a defence against lianes and other climbing plants, which fall off with the flakes of bark.
However, the kauri does tolerate an enormous collection of epiphytic (perching) plants in the massive fork where its main branches separate.
Kauri gum (sometimes called New Zealand amber) is exuded by mature trees. It was formerly collected and used for making varnish (especially for musical instruments), floor-coverings and moulds for false teeth.
Kauri is a conifer. It is monoecious - in other words, both male and female cones are borne on the same tree. Male cones are small and finger-shaped, and drop to the forest floor in Spring when they have released their pollen. Female cones (illustrated) are approximately spherical and look a bit like green golf balls. Immature cones are tightly closed and take 18 months after fertilisation to grow. Then on a hot day, they disintegrate into scales and free-flying winged seeds.
Many thanks to Chris McDowall of the Department of Geography, University of Auckland, for his assistance with this map.
Our purpose-built nursery is home to thousands of kauri seedlings and a range of other locally-occurring species. Seed is collected locally (see the section on cones, above) and planted in individual trays. Healthy specimens are then potted-on into successively-increasing sizes of planter bag. Larger specimens are moved into a hardening-off area, before being planted out in appropriate environments on the Trust's land.