Abstract
Various abiotic and biotic disturbance processes are an integral part of the environment of the Urewera Ranges. Relevant abiotic disturbances include volcanism, landslides, fire, drought, wind, snowfall, frost and hail. Biotic disturbances, or components of, disturbances, include humans, introduced animals, introduced plants, insects anti fungal pathogens. These disturbances exert influences which reflect their areal extent, magnitude and frequency. Actual or potential influences of the above disturbances are reviewed and their relative importance in determining the present vegetation pattern is considered.