Story: Kauri forest
Page 4 – Protecting kauri
Today, kauri is showing its ability to benefit from major disturbances. Saplings are emerging through scrubland where farming was abandoned on kauri-depleted soils. The amount of regenerating secondary forest and scrubland containing kauri (estimated at 60,000 hectares) far exceeds that of the remnant mature forest. The places where kauri grow are being protected and restored by conservation authorities and local communities.
Protection and management
Concerns about the unsupportable rate of cutting kauri and other native forest emerged as early as 1863, and many of the remaining patches of forest were classed as reserves by the early 1900s. Despite this, government policy for managing the remaining forest did not gain momentum until after the First World War.
The last kauri
Artist Rei Hamon was once manager of the Thames Sawmilling Company and had the job of supervising the felling of a large kauri above Tapu in 1961. He recalls, ‘When that tree fell, it had been standing there for maybe a thousand years…I went back later to where it had been standing, and there were birds fluttering around there, kaka and kereru, that had nested in that tree for generations. That was the finish. I handed in my resignation. I vowed never to fell another healthy tree.’ 1
Although foresters continued to manage regenerating stands for timber, public opinion was turning against further logging. In the early 1950s, Professor Roy McGregor led a successful campaign to protect the old kauri stands of Waipoua Forest in Northland. Battles between conservationists and foresters continued until the 1980s. Growing recognition of the intrinsic value of native forest finally led to the end of all logging of live kauri trees in state forests by 1985. The ongoing demand for the timber meant that privately owned resources were targeted until quite recently, when compliance costs outweighed demand.
Threats to survival
Protection from logging has not ensured the preservation of kauri forest. Introduced animal pests threaten native plants and animals. Possums in particular compete for food with rare birds like kōkako and predate their nests, and they strip native trees. But the Department of Conservation faces ongoing public resistance to using 1080 (sodium monofluoroacetate) to control possums in large areas of remote forest.
The spread of weeds into degraded kauri forest is equally damaging. The forest is particularly vulnerable because of the warm, wet northern climate. More than 100 weed species now threaten native habitats in Northland alone.
Kauri dieback disease
A major threat to the kauri is kauri dieback, a disease caused by a fungus-like water mould Phytophthora taxon Agathis. First observed on Great Barrier Island in the 1970s, the disease was formally identified in 2008. The spores of the water mould first attack the kauri roots and then damage the tissues that carry nutrients. The leaves begin to yellow and fall, the canopy thins, branches die, lesions bleed resin at the base of the tree and eventually the tree dies. There is as yet no known cure. The disease has been found in many areas including the Waitākere Ranges, Trounson Kauri Park and Waipoua Forest. In 2012 it was still not detected in the Hūnua Ranges and the Coromandel. Since the spores are carried in soil, the best prevention is to ensure that shoes and any equipment in contact with the soil are clean before visiting a kauri forest. A charter was set up among a number of public agencies to establish a kauri dieback programme and manage the spread of the disease.
Efforts to restore kauri forest now range from official operations to volunteer work. As well as pest and weed control, the Department of Conservation intensively manages a ‘mainland island’ at Trounson Kauri Park, near Waipoua. Community groups tackle weeds and pests, plant and raise native species, and assist the department with associated species recovery. Private trusts like the Waipoua Forest Trust (a joint partnership between the Forest Restoration Trust and Te Roroa, the Māori guardians of Waipoua), Kauri 2000 (a Coromandel initiative), and the Puketi Forest Trust are establishing thousands of kauri seedlings on suitable sites.
Reliable information on growing kauri is readily available. Well-managed kauri stands have good growth rates, and the renewed production of kauri timber on private land has considerable potential. Tane’s Tree Trust, set up in 2001, co-ordinates research and information-sharing, and lobbies the government to promote native timber plantations on private land.
Whether protected for its intrinsic value or managed for its timber, it seems certain that kauri forest will one day reclaim more of the northern landscape.