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| Forest Canopy |
Kauri trees (Agathis australis) are conifers in the
family Araucariaceae, which grow very
large. They can be more than 50 m
tall, develop a girth up to 16 m, and live for more than 2000 years. The genus Agathis includes other kauri trees from Australia, SE Asia and the
Pacific Islands.
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| Kauri tree |
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| Kauri, Agathis australis |
New Zealand
kauris were heavily exploited for their timber and their gum in the past so they
are far less common now.
Fortunately, there are many small areas of forest habitat in the north
of New Zealand where kauri is regenerating well, across much of its original
range. These regenerating groves
of trees are commonly found on steep ridges and hillsides.
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| Kauri bark and gum |
Kauri trees have
distinctive greyish-coloured bark, with a ‘hammer’ mark texture caused by flaking pieces of bark. There are both male and female trees,
which produce cones of different kinds.
Male cones fall to the ground once they have released their pollen,
while female cones take 3 years to mature, turning from bright green to reddish
brown. Once mature, they release
their seeds.
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| Green kauri cone |
Kauri trees
produce a sticky gum, or resin that oozes from their bark, leaves and cones,
fills in holes or damaged areas, and then hardens. This protects the trees from disease, and allows them to
grow to a very old age. Kauri gum used
to have high commercial value, mainly for use as a varnish. Gum diggers extracted the gum from
swamps and soils where kauri trees had grown in earlier times; dropping
branches, and eventually falling to the ground and becoming covered by debris.
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| Forest remnant in Whangarei |
Many other trees
grow in kauri forest.
Some are large,
some small, and many of them are restricted to northern parts of the country, including
tanekaka, or celery pine (
Phyllocladus trichomanoides)
pictured here. The tree fern is another common feature of these forest areas.
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| Tanekaka, celery pine |
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| Tanekaka, celery pine |
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| Tree fern |
