Huia

Size: 2555 hectares

Area description

The Huia biodiversity focus area is protected within the Waitākere Ranges Regional Park boundaries. The terrain is steep and includes the highest point in the Waitākere Ranges.

There are large forest-clad catchments and the native forest extends well beyond the biodiversity focus area. Streams drain through the Huia and upper Nihotupu catchments. They travel over several waterfalls and into the Manukau Harbour at either Huia Bay or Big Muddy Creek.

Despite selective kauri logging that occurred in the rugged upper Huia catchment, the forest composition has remained relatively unchanged. Large, mature kauri and other younger kauri trees grow in dense stands (rickers).

Upper Nihotupu Dam and resevoir surrounded by forests.
Looking west, the Upper Nihotupu Dam and reservoir is surrounded on all sides by kauri and podocarp broadleaved forest (WF10, WF11).
Photo credit: Andrew Macdonald, Biospatial Ltd 2019

Ecosystem description

Within this biodiversity focus area the forest varies from kauri-dominated forest (WF10) with some of Auckland’s best and most mature kauri specimens, grading into kauri, podocarp, broadleaved forest (WF11).

There is an area where broadleaved trees such as tawa and hīnau (WF13) are common. There are also patches of regenerating kānuka-dominated forest and scrub (VS2).

The forest is intact and the plant species diversity is extremely high. Several native plant species that are only found at higher altitudes in Tāmaki Makaurau / Auckland grow here.

Fauna

This extensive area of high-quality forest and streams provide some of the most important habitat on the Tāmaki Makaurau mainland for:

  • forest birds
  • pekapeka-tou-roa (long-tailed bat)
  • lizards
  • pepeketua (Hochstetter's frog)
  • freshwater fish.

Several nationally threatened species can be found here.

Upper Nihotipu Dam, resevoir and surrounding forests of Huia .
The Upper Huia Dam and reservoir in the Waitākere Ranges looking south east. Significant kauri are common and kauri dieback is less established in this catchment.
Photo credit: Andrew Macdonald, Biospatial Ltd 2019

Threats

Unfortunately, kauri dieback, a soil-borne pathogen capable of killing kauri trees of all ages, is present within the forest. Public access is now closed to prevent further spread of this pathogen.

Geological features

The landforms reflect the volcanic origin of this area. The biodiversity focus area includes three Outstanding Natural Features. These are identified in the Auckland Unitary Plan as:

  • Nihotupu Gorge volcaniclastic flysch
  • Karamatura, Marama catchments and Mt Donald McLean
  • Nihotupu pillow lavas and falls.

Related ecosystems

Regenerating ecosystem

Kānuka scrub and forest ecosystem (VS2)

Found throughout New Zealand, kānuka dominated forest establishes readily after fire. It's diverse range of flowering and fruiting shrubs and trees provide habitat for a wide range of invertebrates, birds and lizards.

Threat status
Least concern

Warm forest ecosystem

Kauri forest ecosystem (WF10)

In the north of New Zealand, dense forests of the iconic kauri occur on hill slopes and hill crests. This long-lived forest ecosystem is significantly threatened through the spread of kauri dieback.

Threat status
Endangered

Warm forest ecosystem

Kauri, podocarp, broadleaved forest ecosystem (WF11)

Once widespread across the Auckland region, this warm forest ecosystem contains a range of podocarp and broadleaf trees on different landforms. It is an ideal habitat for birds, bats and lizards thanks to an abundance of fruit and nectar.

Threat status
Endangered

Warm forest ecosystem

Tawa, kohekohe, rewarewa, hīnau, podocarp forest ecosystem (WF13)

This warm forest ecosystem occurs on inland hill country where kauri is absent. It is home to a wide range of common and threatened fauna. In Auckland, species such as kōkako thrive in this ecosystem where pest animal control is undertaken.

Threat status
Vulnerable