Fiordland ecology: Soils and vegetation of Secretary Island
- Botany Division, Department of Scientific and Industrial Research, Lincoln
Western Fiordland provides a unique combination of geology, topography, climate and vegetation. The rocks throughout are granites, schists and gneisses which are extremely hard and resistant to weathering, softer sedimentary rocks being found only in the extreme south-west. The raw glacial topography developed during the Pleistocene has scarcely been modified, and is characterised by irregular summits, precipitous fiord walls, and spurs worn by ice. The climate is excessively wet, and though cool, is equable. Exposure to prevailing westerly winds is an important factor on headlands and on the 'tops'. Up to an altitude of about 3000 ft. the vegetation consists of forest and scrub, nearly all the communities being mixtures of beeches, podocarps and broadleaved hardwoods, while the open tops are occupied by tussock grasslands and herbfields.