Nelson Coast Temperate Forests

The temperate rainforests of the Nelson coast are a globally rare habitat type. They are unusually intact, with coastal forests rising nearly unbroken to alpine herbfields in places. These plants and animals here have some affinities with those of alpine and forest habitats further south in Fiordland, though they are largely absent in the intervening Westland forests due to past glaciations scouring the landscape there. Karst and caves in this ecoregion support an array of endemic plants and cave invertebrates.

Drier forests towards the east are primarily beech (Nothofagus spp.) with black beech (Nothofagus solandri solandri) on drier ridges. Podocarp forests with rich understories of vines, shrubs, and ferns occur in the wetter west. Here, one finds northern rata (Metrosideros robusta), karaka (Corynocarpus laevigatus), and the nikau palm (Rhopalostylis sapida). The yellow pine (Halocarpus biforme) and species of Dracophyllum occur on wet infertile granite-based soils. Half of New Zealand’s 2,450 plant species are found in the region and despite the relatively small amount of alpine habitat, the percentage of alpine flora in the range of 80 percent. Almost 50 percent of the ecoregion’s endemic plants occur on marble or limestone (karst) substrates.

New Zealand kaka (Nestor meridionalis), kereru or New Zealand wood pigeon (Hemiphaga novaeseelandia), and New Zealand falcon (Falco novaeseelandiae) occur. Northern spotted kiwi (Apteryx haastii) and blue duck (Hymenolaimus malacorhynchos) retain populations in the uplands. The Farewell Spit on the northern coast is an important feeding area for about 90 migratory birds and local waders. Paparoa National Park is one of a few mainland breeding colonies for the endemic Westland black petrel (Procellaria westlandica). A rich invertebrate fauna includes the endemic carabid beetle (Cillenum tillyardi), 20 different types of cave weta (primitive cricket-like invertebrates), and the Nelson cave spider (Spelungula cavernicola), New Zealand’s largest spider with a 12 centimeters leg span. The wet beech forests and tussocks in the northwest are home to dozens of giant land snail species (Powelliphanta spp.). Ancient Rhytididae carnivorous snails feed on native worms.

Ninety-five percent of tall forests and tussock herbfield above 600 meters remain relatively intact, mainly in Kahurangi National Park, Paparoa National Park, and Abel Tasman National Park. Tourists trampling fragile higher-elevation habitats is a growing problem. Introduced animals, such as red and fallow deer (Cervus elaphus and Dama dama) and chamois (Rupicapra rupicapra), as well as invasive weeds like gorse (Ulex europaeus) degrade natural vegetation. Indigenous flora, which is not adapted to regular fires, are regularly threatened by human-caused wildfires. As elsewhere in New Zealand, invasive rats, possums, and stoats prey on native birds and invertebrates. 

Key conservation actions for the next decade are to

1. Carry out effective rat, possum, and stoat control in the vicinity of populations of threatened bird and invertebrate species. 
2. Enhance wildfire management and control in drier eastern key biodiversity areas. 
3. Effectively manage visitor traffic to fragile caves and alpine habitats.