Abstracts Earth and Environmental Sciences

Soil loss in a high country catchment : an investigation using fractional acre runoff plots to predict soil loss from a mountain catchment

by John A. Hayward

For the last 100 years, the condition of the New Zealand south Island high country has been the subject of much controversy. Although there are very few records of the condition of this land the time of European occupation one of the first accounts from Canterbury draws attention to spectacular erosion. In 1849 F. Strange climbed to the top of the Torlesse Range and recorded: "The sight that met my view was very singular and wild: whole sides of mountains appeared to have slipped into the immense gullies below, whilst immense blocks of rock had been precipitated, cutting their way through the black birch (mountain beech) trees which line the gullies and carrying everything with them.??? (Quoted by Molloy, 1964.) In the earlier years of pastoral occupation, a few authors expressed concern about the erosion being caused by repeated burning and overgrazing of sheep and rabbits. (Buchanan, 1868: Cockayne, 1919a, b, C; Bathgate, 1922.) However it was not until the late 1930's that these views received very much public support. In 1939 the Government set up an expert Committee to enquire into the maintenance and improvement of plant cover as a protection against soil erosion. This Committee recommended that: ???Statutory and administrative measures should be taken at the earliest opportunity to inaugurate a programme to handle the serious soil erosion, soil conservation and land utilisation problems that now face us...???