Story: Canterbury region
Page 5 – Plants, animals and conservation
Much of Canterbury was originally covered by tall podocarp forests. Kahikatea and mataī trees flourished in fertile, damp sites, while tōtara dominated stony soils.
There was beech forest in the hills north-west of the Rangitātā River, and in some parts of Banks Peninsula. High-altitude forests south of the Rakaia River contained mountain tōtara, mountain cedar and celery pine. Above this, broadleaf, dracophyllum and small-leafed shrubs grew in subalpine areas. Alpine vegetation consisted of tussock grasses and herbs.
Human impact on vegetation
After the arrival of Māori, fires destroyed forests on the plains. They were replaced by tussock grassland, which spread from alpine areas. Other native plants such as matagouri, kānuka, mānuka, kōwhai and wild Spaniard thrived after the fires.
When Europeans arrived, less than one-tenth of the region was forested. Timber was cut or burnt to create pasture, further reducing forests. In the mountains, fires were lit to provide better feed for sheep. This promoted the spread of short rather than tall tussock, and destroyed scrub and beech forest.
On the plains and downs, ploughing and introduced grasses all but eliminated native grassland. On the dunes, marram and lupin replaced native species. Pines, macrocarpa, gum and other introduced trees were planted.
Today, some original vegetation survives only in the alpine zone, in the foothills and on Banks Peninsula. Grasslands and arable farming prevail on the plains.
Human impact on animals
With pre-human habitats different from much of the rest of New Zealand, Canterbury had a distinctive fauna. Wetlands, especially at Te Waihora (Lake Ellesmere), were once home to many fish and bird species. The mixing of cold subantarctic and warm subtropical waters off the Canterbury coast attracted fish, marine mammals and seabirds.
Seals were a food for Māori, and whales were hunted by early Europeans. Other water species were threatened as the wetlands were drained, overfished and polluted.
Local native species at risk include Hector’s dolphins, Canterbury mud fish, alpine grasshoppers, orange-fronted parakeets and several other birds.
Rabbits became a problem when they spread into Canterbury from Marlborough and Otago in the 1880s. Goats and red deer also severely damaged plants. Nassella tussock, a troublesome exotic weed, was a serious problem in North Canterbury.
The moa, adzebill and a native goose were hunted to extinction by Māori. The giant Haast’s eagle disappeared with the loss of its main prey, the moa. The piopio and the laughing owl disappeared after the arrival of Europeans, and the native quail was last seen around 1870. The eastern weka disappeared from Canterbury in the early 20th century. Kiwi, kākāpō, yellowheads, parakeets and tūī have disappeared from Banks Peninsula.
Te Waihora (Lake Ellesmere) and the Avon–Heathcote Estuary were once linked by an extensive wetland across the neck of Banks Peninsula. It formed when the shoreline retreated about 6,500 years ago. The prolific bird and fish life provided a rich supply for Māori, but the land was mostly drained after European settlement.
Cantabrians such as Thomas Potts, Leonard Cockayne and Harry Ell were prominent in the growth of New Zealand’s conservation movement. Conservation is still a major issue. Problems include loss of habitats for native species, pollution and over-exploitation of water resources.
Irrigation, homes and industries, conservation programmes, recreational fishing and power generation compete for water, which once seemed a limitless resource. Nitrate levels in groundwater are worryingly high in some areas. Erosion in the high country is also a problem.
The Department of Conservation in 2005 administered nearly 20% of the land area of Canterbury (including South Canterbury). Reserves were first set aside at Hanmer Springs in 1881 and at Arthur’s Pass in 1901. Small forest reserves were created on Banks Peninsula. Arthur’s Pass National Park became the South Island’s first national park in 1929.
Other initiatives include:
- reserving foothill tussock grasslands such as Korowai–Torlesse Tussockland Park
- creating a 12,000-hectare ‘mainland island’ (a haven for native animals) in the Hurunui valley – the largest of six in the country
- restoring Christchurch’s Travis freshwater wetland, a habitat for the pūkeko swamp hen, whose numbers are dropping in Canterbury.