Agathis australis
Common name
kauri
Synonyms
Dammara australis D.Don in Lamb., Podocarpus zamiaefolius Richard
Family
Araucariaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Trees & Shrubs - Gymnosperms
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
AGAAUS
Chromosome number
2n = 26
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2018 | Threatened – Nationally Vulnerable
Previous conservation statuses
2012 | Not Threatened | Qualifiers: DP
2009 | Not Threatened
2004 | Not Threatened
Distribution
Endemic. Occurring from Te Paki south to Pukenui (near Kawhia) in the West and near Te Puke in the East. Over much of its former range it has been heavily logged, such that the best stands now only occur in the Coromandel and Waitakere Ranges, on Great and little Barrier Islands, and in Northland at Waipoua, Trounson, Omahuta, Puketi, Herekino, Warawara and Radar Bush forests. Despite its northerly limit this species has been successfully grown as far south as Oban, Stewart Island, and seedlings have been observed near planted adults in Wellington, Nelson and Christchurch.
Habitat
The species forms its own forest type - Kauri forest - which is typified by dense canopies of kauri. Common associates in the northern half of its range may include taraire (Beilschmiedia tarairi), northern rata (Metrosideros robusta), rimu (Dacrydium cupressinum), towai (Weinmannia silvicola), and makamaka (Ackama rosifolia). Historically kauri forest seems to have been best developed on river terraces, coastal plains and the generally flat flood basalts of the Tangihua complex, which make the dominant geology of Waipoua, Omahuta, Puketi, Trounson. Some people believe that the hill and range occurrences, which is where most stands can now be seen, are relictual stands not truly favoured by the species, but merely examples of where it can grow, and of course locations where it was usually left because log extraction was less feasible.
Features
Stout, monoecious forest tree 30-60 m tall, with trunk 3-4(-7) m diam. Trunk typically devoid of branches for majority of its height. Trees at ricker development stage have a columnar growth form with trunk scarcely free of branches. As tree matures the basal branches are progressively abscissed, eventually leaving bare trunk typical of mature specimens. Bark blue-grey, falling in large thick flakes with scalloped margins, undersides of discarded bark and freshly exposed underbark rust brown. Leaves (needles) alternate to subopposite, sessile, thick and leathery; juvenile leaves 50-100 mm x 5-12 mm, lanceolate, pinkish green, often black-spotted (a fungus specific to kauri causes this); adult leaves 20-35 mm, oblong, apex obtuse. Male cones 20-50 mm long, stout, cylindrical, female cones globose 50-75 mm diam., cone-scales (carpidia) deciduous, at first broad but then gradually narrowing toward base, bearing one ovule per scale. Seeds ovoid, compressed, margins winged.
Similar taxa
None - though could be confused with the distantly allied Queensland Kauri (Agathis robusta) which is commonly cultivated in warmer parts of New Zealand. Kauri can be distinguished from that species by its smaller, narrower needles, and by the needles often spotted with black. Queensland Kauri is much faster growing but adult trees are not nearly as massive as kauri.
Flowering
Female cones produced from September - December. Male cones throughout the year but most common from September to January
Flower colours
No flowers
Fruiting
Mature cones occur anytime from December through to May, with rare persistent examples found on trees right up to about August
Life cycle
Winged seeds are dispersed by wind (Thorsen et al., 2009).
Propagation technique
Easy from fresh seed. Very difficult from cuttings. Can be grafted onto seedling kauri.
Threats
Now listed as threatened because of the ongoing decline caused by Phytophthora agathidicida for which as yet there is no known effective preventive or treatment. Aside from ongoing losses caused by this disease, kauri on private land remain vulnerable to illegal logging, while trees are still peridoically removed (although only by permit or with approval) for cultural purposes, such as for making waka (canoes) or other Maori buildings and structures. Some small southerly populations are rather vulnerable to goat browse destroying regenerating seedlings and saplings.
Phytophthora agathidicida remains the main threat to kauri. This fungus-like organisim has caused the death of kauri trees throughout large parts of that species range and it is now a serious threat to the species (see the information and links provided below and see images above of lesions and thinning caused by the disease).
Etymology
agathis: From the Greek agathis ‘ball of thread’
australis: Southern
Kauri dieback
Kauri dieback is a microscopic fungus-like plant pathogen (a disease causing agent) that only affects kauri. Research has identified PTA as a distinct and previously undescribed species of Phytophthora. Kauri dieback is believed to be a soil-borne species spread by soil and soil water movement, plant to plant transmission through underground root-to-root contact, and human and animal vectors. Symptoms include yellowing of foliage, loss of leaves, canopy thinning (see image above) and dead branches. Affected trees can also develop lesions that bleed resin (see image to the right), extending to the major roots and sometimes girdling the trunk as a ‘collar rot’. Kauri dieback can kill trees and seedlings of all ages. A new website has been established that focuses on Kauri dieback entitled Keep Kauri Standing.
Follow this link for an up-to-date FAQ (December 2017).
External links
Attribution
Fact Sheet Prepared for NZPCN by P.J. de Lange May 2004. Description adapted from Allan (1961).
References and further reading
Allan, H.H. 1961: Flora of New Zealand. Vol. I. Wellington, Government Printer.
Ogden, J. 1988. Kauri: Key to Auckland’s past. Auckland Botanical Society Journal, 43: 17-19.
Sem, G. and Enright, N.J. 1995. The soil seed bank in Agathis australis(D. Don) Lindl. (kauri) forests of northern New Zealand. New Zealand Journal of Botany, 33 (2). pp. 221-235. http://dx.doi.org/10.1080/0028825X.1995.10410485
Sando, C.T. Notes on Agathis australis. NZ Journal of Forestry.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Agathis australis Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/agathis-australis/ (Date website was queried)