The kauri tree (Agathis australis) is a coniferous tree, a variety of pine, found in the northern parts of North Island in New Zealand. It is a wide, fat tree that nevertheless grows up to 150 feet tall. In their early years, kauri trees have narrow, pole-like trunks. As the trees get older, the trunks thicken and the lower branches fall off. Kauri trees shed their bark in scales the size of plates.
Size and age
New Zealand historian Alastair Isdale noted a tree measuring 80 feet in circumference near the mouth of the Wailhou River on North Island. This tree, known as The Great Ghost, burned in 1890. The Tane Mahuta in Waipoua Forest, named for a Maori forest god, is the largest existing kauri tree standing 168 feet tall and 45 feet in circumference as of 2010. Waipoua Forest is on the northern tip of North Island. The Maoris are indigenous people of New Zealand who originally came from the eastern part of Polynesia. Based on the evidence of growth rings, kauri trees ordinarily live more than 600 years.
Kauri wood, the color of dark honey, has beautiful grains. It is made into tableware, including bowls and furniture. It is sometimes stained to turn it into a greenish hue or a rich, dark brown.
When a branch is broken from a kauri, or the bark is cut, the kauri exudes a resin to prevent rot or water from entering the tree. The amber lumps grow and eventually drop off. The Maori used the gum to make tattoo pigment. They also used it to light fires and as a kind of chewing gum. It was exported to make linoleum, varnishes and lacquers, a trade that dried up with the advent of synthetic substitutes.
The kauri drops highly acidic litter including resin. The tree has a shallow, wide root system that helps prevent the tree from blowing over in storms. The acidic debris that accumulates at the base of the tree decays slowly. Rain leaches the rotting debris into the soil making nitrogen, phosphorus and other nutrients available to the shallow roots.
Decline in Number
When the Maori arrived in New Zealand 1,000 years ago, kauri trees covered much of the northern half of North Island. The Maori used kauri timber to build boats and houses. European settlers in the 19th century felled mature trees for lumber, and shipbuilders discovered that the trunks of young kauri made good spars and masts. Estimates are that kauri stands that once covered 2.9 million acres have dwindled to slightly under 200,000 acres. In 1952, the New Zealand government created the 22,500-acre Waipoua Sanctury on North Island to preserve the kauri tree. By 1987, the Department of Conservation assumed protection of all the remaining forests in government lands.