Regeneration project

Waimarino Bulletin, Volume 4, Issue 24, 11 November 1986, Page 13

Regeneration project

An adventurous project is underway on the Desert Road to plant native bush where land has been left waste after man-made development has been completed. The stretch of road that verges onto the Makahikatoa Stream, within the Tongariro National Park, was left barren after a hair-pin bend on SH1 was removed earlier this year. The area's Lands and Survey Department acting ascontractorsforthe Ministry of Works and Development, launched the project to regenerate the site to make it more pleasing to the eye and to control erosion. Permission was obtained from the New Zealand Forest Service to collect native manuka from a site near Lake Rotoaira which is in the same ecological vicinity as the project. The collection of plants from geographically similar areas ensures that the National Park's policy of genetic purity holds firm. The development is taking place on both sides of SH 1 at the former hair-pin bend site. Loose soil and rocky matter, consisting of greywacke, is layed to a depth of about one metre which is a good base for re-growth. Manuka scrub is normally cut between April and August to allow the seed pods to ripen over the winter months. It is then transported in 500 - 600kg loads by helicopter to the deposit site. A helicopter from Lakeland Helicopters in Taupo drops the bundles of manuka into pre-designated areas with the assistance of ground crews who have the unenviable task of laying each plant lengthwise up the hillside. The work is hot and laborious. The manuka is not planted in the ground — it is in fact layed on the face of the hill, then secured with biodegradable polyester netting that has a life of about two years before it rots into the soil. The seeds in the pods are released when the pods pop open which occurs when they are subjected to critical climatic conditions — the Desert Road is a good example of harsh climate with freezing nights and often scorching days. The seeds are deposited onto the ground and eventually take root to form a new generation — the primary community in the reestablishment of a native forest. The idea of using synthetic netting is compara-

tively new but when cost and efficiency are taken into consideration there is nothing better. It is excellent for erosion control and is less likely to be blown away, unlike other forms of netting. The netting is also very cheap, at just 19 cents per square metre, and when 5000 metres of netting is being layed over a period of days, cost is an important factor. As well as manuka, other native plants including tutu and kohuhu are planted to form the initial layer of the new forest. The intention is to make the plants less palatable to animal predators such as deer and hares that live in profusion in the area by not applying fertilizer or nutritional supplements of any kind for the first year. But it is worth theeffort ... the end result is truly wonderful when a forest springs from apparently barren ground. Restoration is also taking place along the Ohakune/Horopito railway deviation which will result in luxuriant native forest in a formerly barren landscape.