The importance of snow avalanches as a disturbing influence in South Island mountain vegetation

Information from Fiordland, the central Southern Alps. and the Waimakariri Basin is used to show that snow avalanches are a very common disturbing influence on mountain grassland, scrub, and forest. The local patterns of vegetation distribution in the mountains are frequently directly controlled by the positions of avalanche tracks and frequency of avalanching. In turn these depend on the positions of appropriate start zones, conditions favouring unstable snow and the topographic features of slopes.