kauri

Kauri (Agathis australis) is the great tree of northern New Zealand: a conifer capable of reaching 50 metres in height, four to five metres in trunk diameter, and two thousand years of age. The Māori name kauri was adopted directly into New Zealand English by the early 19th century, one of the first Māori words to enter the settler vocabulary, for the simple reason that there was no English equivalent and the tree was immediately and obviously remarkable. To early European visitors, the kauri resembled no familiar species: a vast, straight, branchless trunk rising for twenty or thirty metres before spreading into a great crown. Early naturalists compared it to masts, columns, and towers. The Māori had long understood the tree's significance: in their tradition, the giant kauri Tāne Mahuta (Lord of the Forest) was a living ancestor of the forest atua Tāne, and to fell a kauri required specific karakia acknowledging the spiritual weight of the act.

The colonial kauri timber trade began seriously in the 1820s and by mid-century had become one of New Zealand's most valuable industries. The kauri's timber was extraordinarily useful: straight-grained, durable, easily worked, resistant to marine borers, and available in lengths and widths impossible to find in depleted European forests. Kauri spars and masts were prized across the Pacific, and the timber was exported to Australia, Britain, and North America for construction, ship-building, and furniture. Equally valuable was kauri gum — the solidified resin that the tree produces and that accumulates in massive quantities around the roots and in the soil beneath kauri forests. Kauri gum was used as a varnish for furniture and carriages and later for linoleum manufacture; Dalmatian gum-diggers working across Northland in the late 19th and early 20th centuries produced a significant industry from this fossilized and sub-fossil resin.

The scale of kauri logging was catastrophic. Pre-European estimates place the kauri forest at approximately 1.2 million hectares across the northern North Island. By 1900 the commercial stands had been almost entirely cleared; today approximately 7,500 hectares of mature kauri forest remain, most of it in protected reserves. The speed of the destruction was enabled by exactly the qualities that made kauri valuable: the trees were accessible, their timber was exceptional, and the colonial economy provided both the incentive and the technology for rapid exploitation. The word kauri — which began as the Māori name for a living tree of enormous spiritual and practical significance — became during the colonial period primarily a timber commodity name. The shift in language parallels the shift in the tree's status.

The kauri has a fourth dimension that has become significant in recent decades: its ancient buried history. Beneath the swamps of Northland lie kauri logs that fell during the last glacial period, preserved by the anaerobic conditions for 30,000 to 50,000 years. These 'swamp kauri' preserve wood of remarkable quality — dense, golden, fully intact — and carry within their rings a record of ancient climate and atmosphere that climate scientists use to calibrate radiocarbon dating and reconstruct paleoclimate. The swamp kauri have also attracted a small luxury timber trade that harvests the ancient wood for furniture and decorative objects. Meanwhile, living kauri forests face a new existential threat: kauri dieback, a soil-borne pathogen (Phytophthora agathidicida) introduced through human foot traffic, which kills kauri by destroying their root system. The trees that survived millennia are now threatened by the mud on a hiker's boot.