Kauri Trees

this article will hopefully give the reader an appreciation of just how unique, extraordinary and endangered these trees are.

The Tangihua forest is or was described as a kauri forest

Large mature Kauri

Once thousands of magnificent kauri trees dominated the Tangihua forest. A large kauri tree may have taken over a thousand years to grow which meant it started life prior to 1000AD.

Kauri timber extraction played a major role in the economic development of New Zealand. These massive trees were felled to supply timber for boats and buildings as far away as San Francisco.The result of this and land clearing is that over 90 per cent of the kauri forest standing before 1000AD has been destroyed.

The lodge is surrounded by Kauri and Kauri tree stumps and heads. There are a number of quite big Kauri that survived logging, several of which you can walk to on the The Kauri Grove walk. There are a number of other good trees further up in the bush as can be seen opposite with a 185cm man standing by it.

Many of the walking tracks are on the old ox’s tracks used to bring these trees out to the dams.

Our kauri now face an even worse threat, Kauri dieback. This has the potential to exterminate the last of the Kauri

The Kauri tree

Kauri is the common name for Agathis australis. The kauri tree is the largest tree in New Zealand although others such as Rimu, totara and katakatea are taller the girth of the Kauri tree is significantly bigger giving the tree a much greater volume.

Ancient trees

Kauri trees are considered to be amongst the most ancient trees in the world appearing between 190 and 135 million years ago, the Jurassic period or the time of the dinosaurs. Tane Mahutu one of the oldest surviving Kauri trees is between 1250 and 2500 years old give or take a decade or two

Distribution

The present distribution of New Zealand kauri is restricted to warm northern regions above the latitude of 38°S (north of Kawhia-Hamilton-Tauranga). See map. The dark patches are the major Kauri forests that are left. Most of the older trees in these areas have been felled. The encircled patch is the Tangihua ranges

Present Day

Over 90 per cent of the area of kauri forest standing before 1000AD was destroyed by about 1900. Cut for timber and fires to clear the land is the reason.

Because of their structure and leaves there has been no real disease or pest effecting kauri until Kauri dieback was introduced. This is decimating the populations especially where the diseases has been brought into a forest by humans and then distributed through out the forest by pigs, goats rats through out the forest.

The flaking bark of the kauri tree defends it from parasitic plants, and accumulates around the base of the trunk. On large trees it may pile up to a height of 2m or more. The kauri has a habit of forming small clumps or patches scattered through mixed forests

Growth stages

There are three main stages

1. Saplings –  These grow straight upwards with branches going out along the length of the trunk. The aim to get as high as possible as quickly as possible in search of sunlight
2. Rickers – As the sapling gains in height, the lowest branches are shed to prevent vines from climbing.This tends to happen after 30 -50 years. The name Ricker is a naval term and because that these trees were ideal for naval masts and spas
3. Mature tree – Once the tree merged above the forest canopy, does not then need to grow taller although it does the girth of its trunk increases and its top branches support a spreading crown of leaves.

The Kauri forest

Kauri can exist as solitary trees in broad leaf dominant bush or as dense stands.

The site, soil and temperature determine the type of forest that naturally contains kauri. Many of the remaining forests are on steep difficult to access country due to land clearing for farming.

In a forest environment, mature kauri emerge above the canopy of other native trees. The lower forest can contain a variety of tree species including totara, tanekaha, taraire, tawa, miro and rewarewa alongside juvenile kauri.

At the shrub level a range of plant species can be found including tree ferns, nikau palms, lancewood, hangehange and mingimingi. Kauri grass is commonly found covering the ground below kauri.

Kauri growth requires high light levels but can tolerate low soil nutrient levels. Consequently, kauri seedlings are often suppressed under dense canopies of faster growing species in fertile soils. As a result kauri are often restricted to less fertile soils on ridges or establish en mass after a large disturbance such as a fire.

A range of orchids and epiphytic plants are also often found perching amongst the branches of mature trees.

Kauri – the biggest trees in the forest and even the world.

The kauri tree is the largest tree in New Zealand although others such as Rimu, Totara and Kahikatea are taller the girth of the Kauri tree is significantly bigger giving the Kauri tree the most mass.

The general Sherman a redwood is claimed to be the biggest tree in the world with a maximum girth of 11.1m. compare that to the following

Some of the biggest Kauri trees recorded

1. The Great Ghost was the biggest recorded d Kauri, 26.83 metres in girth and grew in the mountains by thames It was killed by fire
2. Father of the Forests was measured at 22 metres girth and 24 metres to the first branches. It was killed by lightning^.
3. Kairaru in Northland ,had a girth of 20.1 metres and 30.5 m to the first branch It was on Mt Tutamoe south of Waipoua Forest Fire destroyed it

by comparison Tane Mahuta is just a little fellow his girth is 13.77m with a trunk height of 17.68m but still wider then the General Sherman

Cultural significance Maori

Kauri is considered a taonga species by many Māori:

Kauri played an important role in many aspects of early Māori culture: integrated in creation mythology, rituals, war, art and everyday life. Some large trees were given names and revered as chiefs of the forest.

On special occasions, the giant trunks of kauri were used to carve out large waka taua (sea/war canoes). Felling these mighty trees was a difficult task.

In the first step, illustrated here, a large stone adze was attached to a shaft. This was suspended by rope or aka (the stem of a climbing plant) from a branch high above. Several men then swung the adze shaft into the base of the tree, creating a groove or channel. The shaft would then be raised and the action repeated to make a second groove above the first. The block between the grooves would be chipped out with an ordinary stone adze. A trellis would then be built around the tree trunk. A fire was lit in the hollowed-out trunk, and long, stout poles were balanced on the fence with their ends in the fire.

Kauri gum had many valuable functions. Gum was burned as an insecticide in kumara plots, wrapped in flax to make torches for night-fishing and used as a chewing gum (kapia). Kauri resin was also burnt and mixed with fat to create the ink for moko (facial tattooing) of rangatira.

referance Kauridieback.co

European

Kauri timber played a major role in the economic development of New Zealand

25 years after Cook rediscovered New Zealand, the crew of the Royal Navy vessel ‘Fancy’, cut more than 200 spars at Doubtless Bay and from the Coromandel Coast.

Harbours such as the Hokianga had a real boom as 1000s of ships came for the kauri timber not only for ships but for for buildings far away as San Francisco. Auckland and Wellington including parliament buildings were constructed with Kauri.

Kauri gum was used in varnishes, paint, linoleum and to create ornaments. Gum was largely collected from the ground, however some was gathered by deliberately injuring or ‘bleeding’ trees.

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Kauri Dieback

What is Kauri dieback

Kauri dieback is a disease which can kill Kauri Trees of all sizes. It is fungus-like disease caused by Phytophthora agathidicida. It was formally identified in 2008 and is specific to New Zealand Kauri and kills trees of all ages

Kauri die back lives in the soil as a microscopic spore and can be transferred with any soil

What does it do to Kauri Trees

Microscopic spores in the soil infect kauri roots and damage the tissues that carry nutrients within the tree. Infected trees show a range of symptoms including yellowing of foliage, loss of leaves, canopy thinning, dead branches and lesions that bleed gum at the base of the trunk.

Some infected trees can show canopy dieback and even be killed without any gum showing on the trunks as kauri dieback also acts as a severe root rot below ground.

How do we prevent Kauri dieback from entering the Tangihua ranges

The only way we can prevent Kauri dieback is too stop it from spreading into the Tangihua ranges

The main way it spreads is through humans moving it from one forest or tree to another forest

• Clean and remove soil from your shoes and equipment before and after entering kauri forest areas.
• Keep to the defined tracks in parks.
• Stay away from kauri tree roots as much as possible.
• Do not take vehicles off the road or parking spots
• bikes must be thoroughly washed before leaving for the ranges