Chatham Islands, New Zealand

This is the first of a series of articles describing the diverse landscape and conservation values of several land areas within the Chatham Islands group.

South west Chatham Island encompasses dramatic coastal scenery, a fertile farming belt and forested catchments rising to a moorish tableland containing lakes and low peaks.  The south-west supports the most extensive forest on Chatham Island, expanses of upland bamboo rush & Chatham aster and important populations of threatened plants and animals.  It is the only breeding sites in the world for taiko and the Chatham Island mudfish.  The largest protected area occurs here with the Tuku Nature Reserve and adjoining South Chatham covenant at about 2,500 hectares. 

The tableland is highly distinctive.  The flat to undulating topography belies the fact it is the highest region of Chatham Island at 250-280m altitude.  The island's tallest peaks occur on the tableland's northern edge. 

The south-west climate is damp compared to the north of the island.  Cloud cover is more persistent inland resulting in higher rainfall and lower evapo-transpiration.  The gentle topography slows drainage producing wet ground conditions that favour moisture loving species such as sphagnum moss and the endemic bamboo rush (native only to Chatham Island). The latter grows with swamp heath and the endemic shrub swamp aster which produces abundant purple daisies.  Dead plant material only partially decomposes in the wet conditions and accumulates as peat beds.  Under the bamboo rush/heath community the peat may be 9m in depth it overlies ash from the Taupo eruption of 20,000 years ago while water can be found about 50cm below the surface.