Hunuas Attract North Shore Naturalists

Forest and Bird, Issue 185, 1 August 1972, Page 20

Hunuas Attract North Shore Naturalists

A LARGE audience of members of the North Shore Branch and the public heard Mr I. L. Barton, senior Auckland Regional Authority forester speak in April on the Hunua Water Catchment area. The talk revealed that there was much more to this large area than merely water catchment and forest; it contained diverse flora and fauna, including a species of very rare native frog. Mr Barton explained that though the primary use of the area was for water catchment, the Authority was planning that certain portions should be used for recreation and others would be set aside as nature reserves. Forests in such an area could serve as protection forests to prevent soil erosion and provide income through the production of timber. The two completed dams already in use produced 4| million gallons of water a day and two more were being developed. A third was planned for construction within the next 10 years. These five would produce 90 million gallons a day. For recreation there was the prospect of a golf course being established in one locality, and another area which would go down to the Firth of Thames coast would have a network of walking tracks with overnight camping huts. For the really hardy trampers a further area, essentially rugged in nature, would be reserved. No Deer Mr Barton said that it was fortunate there were no deer in the Hunuas, though there were plenty of browsing animals, mainly opossums, goats, and pigs; 35,000 of these had been killed since an eradication programme had been started. The indigenous forests had been much altered by the presence of these animals. However, new management techniques and the use of fertilisers were bringing back something of the old kauri forest. A successful technique of thinning involved the removal of kauris 8 in. in diameter, which had been bled for their gum; this resulted in young poles being left with a better chance to survive. Growth rates rose from 0.2 cu ft a year when trees were left untouched to 0.7

cu ft when trees were reduced to 300 stems to the acre and fed with fertiliser. This could indicate an 80-year cycle for the development of kauris to millable timber. Guided Tour A week or two after the talk Mr Barton and his assistant, Mr A. Dakin, conducted about 80 members and their children and friends on a tour of the Hunuas. The first stop was at the nursery, where trees and shrubs were being grown from seed or cuttings. The neatness and orderliness were impressive, as was the preponderance of native plants among the stock being propagated; many of the techniques for the propagation of native species originated in the nursery. The party moved on to see Mangatawhiri Dam, where beautification efforts have obviously succeeded. A stop for lunch in a charming bush-clad valley, which would later be inundated with water on completion of a further dam, gave members an opportunity to collect some native plant seedlings. The final stop was at the site of the third dam now being built. Mr Barton pointed out to the group an experimental area where thinning and fertilising of kauris were gradually increasing the girth-growth rate. All were most impressed by the magnificence of much of the native forest in the Hunua area and by the beauty of the valleys. The trip left all with a feeling of gratitude and optimism that here indeed was a dedicated group of foresters who understood the value of developing techniques which would help perpetuate New Zealand’s indigenous forests and even allow them to compete in economic terms with the fast-growing exotics.

No Summer Camp

WE regret that there will be no camp next summer. No branch or section offered to hold a camp, and a final attempt to organise one at Gisborne failed because of prior bookings.