The Desertification of Central Otago, New Zealand

Abstract

The utilization of tussock grasslands in the semi-arid and sub-humid tussock grasslands of Central Otago, South Island, New Zealand, by European sheep farmers, began during the 1850s. Many of the sheep farmers and their hired shepherds migrated from the Scottish Highlands, and brought with them the management practices with which they were familiar. The extensive sheep farms or ‘runs’ were rented on government-owned land, and the graziers did not enjoy long-term security of tenure; nor did they receive compensation for any improvements which they might have undertaken during their occupancy.The combination of frequent burning of the vegetation and overgrazing soon resulted in a perceptible decrease in vegetation cover, such that land deterioration accelerated in the 1870s and 1880s when a rabbit pest irrupted. No effective action was taken to deal with the problem of land deterioration, and by the early part of the twentieth century parts of Central Otago were described as man-made desert. The tussock grassland had given way to almost bare soil interspersed with patches of Scabweed (Raoulia lutescens), and accelerated soil erosion resulted in slope-wash and gullying. Remedial action was delayed by the outbreak of the First World War, but a major Commission of Inquiry at the end of the war concluded that unsuitable forms of land tenure had contributed significantly to the desertification and land deterioration.Eventually, changes in land tenure were introduced, providing for security of tenure, entitlement to compensation for land improvements, and controls on husbandry and stocking levels.