The Manawatu Dunefield: Environmental Change and Human Impacts

Four stages of environmental change are apparent in the Manawatu coastal landscape: the first stage was that of a world wide sea level rise and initiation of the first major dune phase (Foxton or phase I) in the Manawatu. This was followed by a second dune-building phase (Motuiti or phase II), which was probably initiated by climate change. The second stage occurred in the last 600 to 1000 or so years when Maori first occupied the area, rapidly causing the extinction of a range of fauna, significantly altering the vegetation cover and potentially initiating or assisting the development of a new dune phase (Waitarere or phase III). The latter part of the Waitarere phase (phase IV) or episode may have been initiated by Europeans in the last 150 years. The third stage of environmental change occurred in the period 1940 to 1990 when large scale sand sheets and transgressive dunefields were significantly stabilised by humans, and parabolic dunes were created. A fourth stage is just beginning where an entirely new suite (or episode) of parabolic dunes has developed from blowouts within the foredune in the last 10 years. Overall, human impact has wrought major environmental changes to one of the greatest examples of Holocene dunefields in New Zealand.