SPECIAL CONNECTION: Nicole Whaititi, 10, who is part-Moriori, looks at fading Moriori dendroglyphs carved on a tree in the Chatham Islands.

Erosion is wiping away ancient tree carvings on the Chatham Islands, but 3D laser technology is being used to record the spiritual images.

The technique, being used for the first time in New Zealand, is digitally reproducing the images with more detail than can be seen with the naked eye.

Conservation Department technical support officer Richard Nester said the carvings – of people and their environment – could be as old as 300 years, but were on trees unlikely to survive much longer because of disease and wind erosion.

The carvings were done by the Chatham Islands Moriori people, who lived on the islands before the arrival of Maori, and Europeans in 1835.

They are on karaka trees, known as kopi by the Moriori, and most of the carvings are on trees contained within the DOC national historic reserve, Hapupu.

Years of farming had cleared the land around the kopi forest, and Mr Nester said the strong winds that buffeted the Chathams meant the trees had little protection from the elements.

The 33-hectare reserve was fenced in 1980 to protect the forest from grazing cattle, but the trees were still exposed to the elements and also at risk from a native beetle which fed on the trees.

Hokotehi Moriori Trust is working to revive the Moriori culture, and chairwoman Shirley King said learning that the images had been captured forever was an emotional moment. On the island, the trust is working to pass down the ancient art of carving, but few people have had the skills passed down to them from their ancestors.

Comparing the carvings with their digital counterparts was like comparing two different images, Ms King said, because the laser scanner used in the project was able to pick up greater detail than it was possible to see on the eroding trees. As the trees would not survive for much longer, the project had come at a crucial time. "These are living entities and they are dying," she said.

Trust member Mana Cracknell said the trees were like "corpses", but the carvings were spiritually important to a culture which needed to be preserved.

Mr Nester said a team of seven surveyors and archaeologists from Otago University joined DOC for a month on the islands for the project, Ninety-eight carvings from 93 trees were scanned. Using a hand-held laser scanner, they were able to capture the images at a resolution of 0.5mm. Using a laser scanner meant the carvings could be recorded by a non-invasive method which did not put them at further risk. It is estimated that kopi trees are being lost from the forest at a rate of 20 a year, and at that rate they will all be gone by 2015.

Chatham Islander and part-Moriori Nicole Whaititi, 10, said the carvings were called dendroglyphs, and a special aspect of the Moriori culture she identified with.