Mount Young - Hirakimata

Size: 2885 hectares

Site description

The Mount Young – Hirakimata biodiversity focus area is situated on public land on Aotea / Great Barrier Island. The Mount Young - Hirakimata biodiversity focus area covers both Mount Young and Hirakimata / Mount Hobson. The land is administered by the Department of Conservation.

It is an extensive area of continuous native vegetation on rugged volcanic terrain.

Mountainous interior of Great Barrier Island and Hirakimata / Mt Young.
Hirakimata / Mt Young (centre right) and The 'Hogs back' in the foreground. Kauri, tōwai, rātā, montane podocarp forest (MF25) occupies the higher altitude areas of this BFA.
Photo credit: Andrew Macdonald, Biospatial Ltd 2019

Key ecosystems

The ecosystems found within this biodiversity focus area include:

  • coastal forest (WF4) and pōhutukawa treeland on coastal cliffs (CL1) along a stretch of open coastline and within a sheltered bay on the west coast of the island
  • a mosaic (mix) of kauri, podocarp, broadleaved forest (WF11) and regenerating kānuka forest and scrub (VS2)
  • a stand of kauri-dominated forest (WF10)
  • rocky inland bluffs (CL6)
  • high-altitude cloud forest with kauri, tōwai, rātā and montane podocarps on the highest peaks of the island (MF25)
  • many permanent and ephemeral streams including the streams which flow into Kaitoke Swamp.

Hirakimata is the highest point on Aotea / Great Barrier Island, at 627m above sea level. It is on this and surrounding high peaks where the high-altitude cloud forest (MF25) is found.

An extensive tract of forest and scrub cover the rugged terrain to the south and west of the summit of Hirakimata. Remnant kauri forest and regenerating kauri are found in the Wairahi Reserve. Some of the kauri stands are infected with kauri dieback, a soil-borne pathogen capable of killing kauri trees of all ages. Track upgrades have been completed and hygiene stations are in place to prevent further spread of kauri dieback.

Hirakimata / Mt Young.
Hirakimata / Mt Young.
Photo credit: Andrew Macdonald, Biospatial Ltd 2019

Key species

There are three plant species present here that are found only on Aotea / Great Barrier Island.

Threatened and At-Risk seabird species, takoketai (black petrel) and Cook’s petrel, nest in burrows high up on Hirakimata.

Other native animals found within this biodiversity focus area include:

  • kākāriki
  • kākā
  • toutouwai (North Island robin)
  • koekoeā (long-tailed cuckoo)
  • pekapeka-tou-roa (long-tailed bats)
  • native lizard species.

Conservation

There is an animal pest control programme underway, set up by the Department of Conservation with additional support from Auckland Council. The programme was established to help protect the seabird breeding populations and also to enhance the habitat value for other native plants and animals found here.

Related ecosystems

Cliff ecosystem

Pōhutukawa treeland, flaxland and rockland ecosystem (CL1)

This ecosystem occurs on coastal rock faces and eroding hill-slopes around the Auckland coastline and on offshore islands. It contains a mosaic of different plant communities including herbs, flax, shrubs and trees.

Threat status
Vulnerable

Cliff ecosystem

Hebe, wharariki flaxland and rockland ecosystem (CL6)

This ecosystem is strongly influenced by environmental conditions such as high rainfall, earthquakes and soil moisture. It includes a mosaic of vegetation communities including lichens, herbs, grasses, sedges and low forest species.

Threat status
Least concern

Mild forest ecosystem

Kauri, tōwai, rātā, montane podocarp forest ecosystem (MF25)

Found on steep volcano summits, this ecosystem experiences high rainfall, long periods of cloud cover, high to gale-force winds and occasional snowfall.

Threat status
Endangered

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

Pōhutukawa, pūriri, broadleaved forest ecosystem (WF4)

Scattered along Auckland's coastlines, this broadleaved forest ecosystem provides an important source of food for kererū. They are also important seed dispersers for many species in this ecosystem.

Threat status
Endangered