Okura Bush Update Autumn 2021 – Site Visit

In May 2018, a rāhui was placed on the Okura Bush due to poor track design and maintenance. Heading into winter with a track covered in mud with stressed and exposed tree roots raised alarm bells throughout the community.

Local mana whenua iwi met with the community and our Conservation Department for the closure of this forest. This was to give time for track repairs and an upgrade to better protect the beautiful ancient trees including kauri, kahikatea, kowhai and taraire, from root damage and eliminate mud to reduce the spread of kauri root disease.

On the 28th of April, members from Friends of Okura Bush joined with DOC and mana whenua to walk through the Okura Bush to consider the lifting of the rāhui.

The group included Edward Ashby from Te Kawerau a Maki, Te Ao Rosieur and Demi from Ngati Manuhiri, and six staff members of DOC, including Rebecca Rush (Auckland’s Mainland Acting Operational Manager).

Prior to the rāhui being placed both mana whenua and FOOB had expressed some of their reservations and recommendations about the necessary upgrades needed to DOC. FOOB has raised some ongoing concerns throughout.

We were pleased to see that some recommendations had been adopted, such as a timber ramp over the damaged roots of a large kahikatea that is suffering from root and trunk rot as well as the tying back of supplejack from the track. However, the society would still like to see an extension of boardwalk in some places to further protect trees. The mana whenua groups raised concerns about the mud still present on the track, the decision to put plastic geoweb onto the forest floor, and other issues about incorporating Māori aspirations in management of the track. The Society looks forward to further consultation between DOC and the mana whenua groups so we can resolve these issues as soon as possible in order for the rāhui to be lifted.

We will keep you posted!

P.S. We are still in the process of getting approval from our Conservation Department to remove invasive predators from inside Okura Bush. Fingers crossed it will come soon.

Additional info re Geoweb

Purpose:
To provide a dry track surface.
To reduce the spread of Kauri root disease spores.

Method:
Plastic honeycomb shaped webbing with holes in the sides to allow drainage and root growth into the cells. Cells are filled with a mixture of bark and aggregate. Surface capped off with aggregate. Plastic Bidim cloth usually laid on the ground first. (This is very unnatural and can create moisture stress on kauri roots. Much of the cells in Okura Bush have had lime used instead of bark.)

Result:
It does dry out the track in many cases but is fundamentally flawed in that it is designed to promote root growth (roots feed on the bark) which over time as bark decomposes feeder roots of sensitive trees become compacted, damaged and stressed by foot traffic making them more prone to drought and disease therefore having the opposite effect that it set out to do, protect kauri. As cells are compressed over time they are to be topped up again with aggregate bi-annually which adds stress to trees.

Friends of Okura Bush have based their concerns on a botanical report done by our Conservation Department.

Taraire – puriri – kowhai coastal forest is extremely rare. FOOB feel our department has undervalued both the ecological and educational importance of it. This is not just a bush, it is a rare pre-European remnant of Auckland’s coastal forest. Kauri trees are topical but are not what makes this forest rare.

Bark is a good solution for most native forest trees. It’s inexpensive and roots thrive in it. However for kauri and some other very sensitive trees such as Kahikatea and Taraire, best practice is to put in timber ramps or boardwalks which take feet off roots and let roots thrive naturally.

Timber ramps are low cost, easy to install, move and replace.
We hope for a future where our Department of Conservation values the educational stories we want our trees to tell and work together with us on assets and interpretation such as at the grand old Puriri tree, an icon of the North Shore.

Sensitive trees must be valued and protected to a standard that is acceptable to the forest and the public. All important native forests need local guardians who are committed. Friends of Okura Bush are here to stay to ensure the long term vision of restoring the ecology & mauri.

Below; Karepiro Forest Geoweb – 2 years of Kauri root growth

Plastic geoweb creates stressed kauri roots and provides a city experience in the forest.