U.S. Expert’s Review Of Erosion In N.Z.

Press, Volume CIV, Issue 30764, 31 May 1965, Page 1

U.S. Expert’s Review Of Erosion In N.Z.

It was paradoxical that, while New Zealand had received international acclaim and attention for the level of production from plains and rolling lands and exotic forests, experts in land use in many fields from many countries had described the use and condition of her steep lands and sensitive hill" country as shocking, Dr. R. E. Dils, professor of watershed management at Colorado State University, said in a report presented to the management committee of the Tussock .Grasslands and Mountain Lands Institute last week.

Dr. Dils, who has been in New Zealand for about 10 months as a Fulbright research scholar working with the institute, is believed to have made a more exhaustive study of soil erosion and soilconservation problems in New Zealand than any other American.

New Zealand’s own specialists had substantiated the opinions of the visiting experts, and many New Zealanders were aware of the seriousness of these problems. but Government organisation, co-operation, and policy had been poorly defined or non-existent, and public awareness of the problem had been inadequate, Dr. Dils said. Action to improve catchment conditions and prevent further deterioration was painfully slow. ACCELERATED EROSION

Questioned yesterday. Dr. Dils said that undoubtedly there were unusually high rates of natural erosion in New Zealand, but he believed that the burning of tussock, removal of bush, grazing of domestic animals, and the introduction of wild-life had contributed tremendously to ranidly increasing erosion.

It was extremely unfortunate. he said, that photographic facilities had not been so good and stream gauges had not been put in when the Europeans began to settle the country. Dr. Dils’s first recommendation is that active steps should be taken to measure the extent and amount of erosion taking place. Similarly, he is proposing that the contribution of noxious animals to erosion problems should be specifically measured. If action were not taken quickly the cost of trying to remedy the situation would be a great deal more. Dr. Dils said of the high lands on the eastern side of the Southern Alps that many persons considered that there there was some of the most spectacular erosion in the world. The consensus of land-use specialists, from both within and outside the country, was that much of the problem area in the South Island high country should be retired from any intensive use. This involved virtually all the high country which would be classified by agriculturists as class VIII land, as well as class VII land which was already severely eroded and on the move. ECONOMIC STUDIES

Dr. Dils recommended that a series of economic studies should be made of high-coun-try land use in the event of the more sensitive high lands being retired from intensive use and adjustments being made in the use of other steep land. Some form of subsidy or cost sharing, he said, would be warranted to aid in these adjustments, which would be in the national interest. In extreme cases it might be in the public interest to purchase leases or even stations in making these adjustments. In the interest of increased production in the light of the possible retirement of some of the steeper lands from farming, Dr. Dils proposed more intensive study of the control and eradication of noxious weeds on the downs

and rolling country, where frequently thousands of acres are under gorse, manuka, fern, and other weeds. TAUPO AND GISBORNE

Some of the country on the pumice around Taupo, which had been developed only for about seven or eight years, was eroding quite rapidly, and increasingly large areas were going out of production each year, he said.

The high productivity of these lands indicated the desirability of developing them, but in future planning the steep hillsides and more sensitive sloping lands should remain in bush. Where areas had been cleared and problems created exotic trees should be planted. In the Gisborne area where erosion was severe, possibly 50 per cent of this country should be returned to forest to protect the remaining country. Even if the entire area were put under this sort of cover there would still be much erosion, though it would be greatly reduced, he said FORESTRY A realistic assessment should be made of probable long-term export possibilities. This could have a decided impact on decisions about future land use. It could be that the best way of using most of these problem areas would be in production forestry. The growth potential of exotic forests appeared very high by world standards, and there appeared to be a continuing increase in world demand for pulp and fibre and timber products. “The use of these lands for forestry purposes would undoubtedly provide the most efficient method of erosion and flood control, and in the

long run would entail the least expenditure of public funds in catchment management and control,” Dr. Dlls said. TRAINING OF STAFF As a basic requirement of the research programme that he envisages. Dr. Dils recommended that attention lie given to training staff for this work. There was now no special training in catchment management as such, he said. Training could be based on such facilities as would be available in Christchurch and Lincoln with a forestry school to be established at Ham, an agricultural engineering institute and agricultural programme at Lincoln, and the civil engineering department at Canterbury University. Where research was initiated it should be located close to universities and existing research agencies to avoid duplication of equipment.