The loss of New Zealand's active dunes and the spread of marram grass ( Ammophila arenaria )

  This article examines the decline of New Zealand's active dunes in relation to the introduction of marram grass ( Ammophila arenaria ). The area of active dunes in New Zealand declined from 129 000 ha in the early 1900s to about 39 000 ha in 2000; a reduction of 70%. The extent of active dunes has declined since the 1950s in all regions, particularly in Northland, Auckland and the Manawatu. The loss of active dunes on the west coast of the North Island resulted primarily from the introduction of marram grass, followed by the establishment of Pinus radiata plantations and extensive pastoral farming. Between 1985 and 2005 marram grass extended its range to the detriment of the indigenous foredune flora. Conservation and resource management agencies should urgently identify dune systems for conservation management and marram grass eradication.