Swamp kauri

Information about swamp kauri, also known as ancient kauri, and the role of MPI in its milling and export.


Supreme Court decision relating to exports 

On 9 November 2018, the Supreme Court of New Zealand released a judgment that includes interpretation of what a finished or manufactured indigenous timber product is (under section 2(1) of the Forests Act 1949) relating to exports (under section 67C(1)(b)).

Find out more about the decision and exporting indigenous timber and timber products

Relics of old New Zealand 

Swamp kauri timber, also known as ancient kauri, is milled from kauri trees that have been buried and preserved in peat swamps for between 800 and 60,000 years. Some kauri were up to 2,000 years old when they fell.

Swamp kauri is a broad term applied to timber that varies in age and the way it's been preserved. Most swamp kauri is found in Northland but some has been found as far south as Waikato.

Kauri can grow:

  • on a wide range of soil types
  • up to 800m above sea level.

Due to agricultural expansion, many of Northland's kauri sinks (sites of buried, preserved kauri) are covered by farmland.

Creating swamp kauri

Kauri grow best in moist ground. As they age they become incredibly heavy – this weight can cause them to slowly sink into the ground.

For swamp kauri to be preserved the way it has, and for as long as it has, specific needs had to be met:

  • the ground around the trees had to be damp enough to allow the fallen trees to sink.
  • the trees had to be sealed off from oxygen exposure as oxygen is necessary for decomposition.


There is no single set of circumstances that produced swamp kauri. The geology, environment and landscape of the places it's found vary hugely. The most common preservation environments are lowland bogs and peat swamps.

Other environments known to preserve kauri are:

  • dry river beds
  • coastal sand dunes
  • wind-formed sand dunes that have stabilised as climate conditions have changed – these dunes often left sheltered areas that filled with water, organic soil or both and were colonised by kauri
  • infilled volcanic craters
  • ancient lakes
  • hilly areas where landslides have toppled and trapped kauri.


Under the Forests Act, a swamp kauri stump is:

  • a lower portion of a trunk
  • with or without roots
  • partially in the ground
  • no taller than its widest point at ground level.

The ground line, or width at ground level, is the diameter of the tree at the point it would have naturally begun to protrude from the ground.

Swamp kauri infographic. Click link below to download full size PDF.
Infographic showing how swamp kauri can be formed and how to determine whether it is considered a stump.

Download a full size version of the infographic [PDF, 4.6 MB]


In 2016, MPI commissioned 3 pieces of independent research into swamp kauri. This was done in response to suggestions made by the Auditor-General in a 2015 report. The research focused on:

  • scientific values
  • cultural and heritage values
  • the amount and distribution of swamp kauri.

Researchers found that swamp kauri holds significant scientific, cultural, and heritage values for New Zealand.

Scientific values

Swamp kauri has widespread scientific value.

  • It can help improve our understanding of the natural history of New Zealand.
  • Scientists use swamp kauri to study ancient ecosystems and climates, measure environmental change, improve radiocarbon dating, and to analyse extreme events.

The greatest risk to this scientific value is if scientists do not  get the chance to study swamp kauri before it is milled or exported.

The report recommends MPI involve scientists from the time a potential excavation site is identified, through to the granting of milling and export approval.

MPI will discuss this recommendation with Northland's regional and district councils, swamp kauri operators, and other interested groups.

Cultural and heritage values

New Zealanders prize swamp kauri for its age, its appearance, and its rarity. They also value the environment swamp kauri is found in, because these places often hold heritage and historical value – especially for Māori.

There is a tension between the values that people place in the timber, and the value people place in the surrounding environment. There is potential for damage to the archaeological and environmental values of the land when swamp kauri is extracted. 

The report made several recommendations to manage this tension. MPI will discuss these recommendations with Northland's regional and district councils, swamp kauri operators, and other interested groups.

Swamp kauri distribution and remaining volume

NIWA (the National Institute of Water and Atmospheric Research) has mapped the distribution of swamp kauri in Northland based on soils, land forms, and historic information. This has found that:

  • About 78% of potential swamp kauri sites have no mapped ecological values. Most of this is likely to be farmland. However, field inspections are still required to determine whether extraction is suitable.
  • Between 50% and 70% of Northland's swamp kauri is still in the ground. However, it is highly likely some of this would not get approval to be extracted or milled.

Download the report: Swamp kauri resources of Northland [PDF, 15 MB]


MPI is responsible for regulating the milling and export of swamp kauri under the Forests Act 1949.


Responsibility for the extraction of swamp kauri rests with local and regional councils under the Resource Management Act 1991. If you're planning to extract swamp kauri, check with your local council whether you'll need resource consent.

MPI also oversees all current extraction sites. Sites are inspected before and after extraction activities to:

  • assess the land's classification
  • ensure only the approved land has been worked.

MPI should be notified of any proposed extraction before work begins.


Swamp kauri can only be milled if MPI has issued a milling statement for the timber. Applicants must meet a range of criteria – including demonstrating that the swamp kauri will be salvaged from land that is either:

  • not indigenous forest, or
  • indigenous forest where extraction will not diminish the land's natural values.

Milling statements are most commonly issued once MPI has conducted site inspections.

Milling statements are valid for between 6 and 12 months and cover only the volumes covered by the application. If some timber has not been extracted when the milling statement expires, you may apply to MPI for a renewal.

Milling may only be done at MPI-registered sawmills.

If you don't plan to mill your swamp kauri then you don't need to obtain a milling statement.


Exports of swamp kauri are subject to strict rules. Swamp kauri can only be exported as:

  • a finished product
  • whole or sawn stumps or roots – provided the timber didn't come from indigenous forest land.

The definition of a stump under the Forests Act is very specific.

swamp kauri stump measurement
Extracted swamp kauri stump showing height and groundline measurements.

Stumps and roots intended for export must be visually inspected and approved by MPI before they leave New Zealand. Customs will not provide clearance until this has been done.

Breaches of these rules may incur, among other things, a fine of up to $200,000 on conviction.

In general, more swamp kauri is kept in New Zealand than exported. In the second quarter of 2016:

  • about 1,500 cubic metres were approved for milling (milling statements were issued for the milling of 1,500 cubic metres)
  • less than 200 cubic metres were approved for export.

Forms and resources

MPI has specific forms for use by swamp kauri operators. They:

  • help swamp kauri operators give adequate information with their applications
  • enhance public understanding of swamp kauri activities
  • improve oversight of all steps of the swamp kauri supply chain, from extraction and milling to export.

Download the forms:

We also have a fact sheet to help land owners and operators manage and understand their responsibilities.


MPI encourages operators to record their extraction activities in a swamp kauri logbook. Accurate record keeping helps improve traceability of swamp kauri timber.

Where logbooks are not properly maintained, MPI may not be able to assess or issue milling statements or approve export applications.

To request a swamp kauri logbook, email swamp.kauri@mpi.govt.nz


MPI produces reports that provide information on the quantities of swamp kauri being milled and exported.

All reports are based on data reported to MPI in our capacity as regulators under the Forests Act 1949.

Official Information Act responses

MPI has published all responses regarding the milling and exporting of swamp kauri made under the Official Information Act since July 2012.

Investigation by the Auditor-General

In response to public requests, the Auditor-General completed an investigation into swamp kauri management under the Forests Act by MPI. The report concluded there was no evidence of MPI allowing the illegal export of timber or timber products.

The Auditor-General made 4 suggestions to improve oversight and management of swamp kauri resources under the Forests Act. MPI is acting on those suggestions.  

Who to contact

If you have questions about the information on this page, email swamp.kauri@mpi.govt.nz

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