To Pine or not to Pine – that is the question!
The Friends of the Maitai email inbox recently ran hot with debate over pine forestry, with some on our mailing list claiming we are too tough on forestry in the catchment: “The biggest threat to the Maitai River is erosion from the thousands of hectares of pine forests that dominate the catchment. The large clear-felling of pine forests allows significant rain events to erode the steep hillsides with most of that soil ending up in the river (and subsequently Tasman Bay).” FOM News Flash November 2020
Roger May from Tomorrow’s Forests who has long been a supporter of FOM, wrote this comprehensive response to the pine defenders, and we think it’s worth sharing.
- True, Radiata pine is a useful timber especially for laminated veneer lumber (LVL) and
plywood. It is also quite good for (house) framing although Douglas fir is probably better
(stronger & stiffer).
- Most Radiata harvested in NZ is exported as logs and a small amount arrives back here
(imported) as finished products. The value of Radiata exports is about $6.4 billion annually. A
high proportion of the exported logs is used to make construction ply, pallets, and packaging
- Domestic (ie. NZ) consumption of Radiata pine is about 1/3 of the annual harvest.
- A significant proportion of domestic consumption is in the form of posts, poles and other in-
ground or close-to-ground use. This requires treatment by CCA (copper chrome arsenic)
preservative. Over the last 10 years we have imported 4,000 tonne of raw arsenic salts to treat
Radiata to make it ground-durable. While some of this treated timber is exported, most goes into
our NZ environment. (NZ Customs Arsenic import figures are available.)
- NZ currently imports about $1.2 billion worth of timber and timber products annually. I have
the import data and the analysis from 2000 to 2020 if anyone needs them. Very few Kiwis ask
about the quality of forest management or certification of these timbers when they buy imported
timber or furniture. We have effectively exported our special-purpose timber footprint. None of
that is acceptable.
- On a global scale, Radiata is a medium grade timber at best. It has its uses but the volume
and value of special-purpose timber imports shows that we could be growing a lot more high
quality timber for our own use.
- So why aren’t we growing more of our own special-purpose timber? (Partly because
corporate pine companies largely control the research budgets and these timbers have needed
more research for years.)
- In addition, we could be growing our own naturally ground-durable species and stop
pumping all the CCA-treated pine into our environment. (Google the NZ Dryland Forestry
- Radiata pine has to be harvested using clear-cutting (large areas felled at a time) because
it is not economic to use any other harvesting system. It is not economic to use shelterwood or
continuous canopy harvesting systems in Radiata because the value of the logs is insufficient to
cover the higher costs of these lower impact methods.
- It is the clear-cutting of Radiata, especially on steep and/or fragile terrain which results in
sedimentation and damage to our waterways. Large scale corporate forestry (pine) does tend to
look after the larger waterways but pretty much ignores the smaller (low order) waterways.
Felling trees or extracting logs through 1 st and 2 nd order streams is common. And like Peter says,
riparian margins have a limited effect when there are large clearfelled areas above them.
- In 2018 MfE stated that NZ erosion amounted to 192 million tonnes. Many places across
the country have erosion that exceeds 1 kg per square metre per year. For most of the public,
this problem is largely out of sight but is ubiquitous. And clearcut forestry is a major contributor to
this problem in hilly terrain irrespective of steepness or fragility.
- The best interim solution for harvesting Radiata pine is to limit clearcut size and the
aggregation of clearcuts. (At present there are few meaningful constraints in the National
Environmental Standards for Plantation Forestry (NES-PF) that allow Councils to write rules
controlling clearcut size. This needs to change.)
- We need to stop planting (and replanting) Radiata pine on steep and/or fragile terrain.
Instead we need to either retire and manage those hillsides back into native forest OR plant
higher value timber species so that harvesting can be economic when low-impact, shelterwood,
or continuous canopy harvesting systems are used.
- The decision as to whether terrain should be returned to native or be planted in high-value
exotics (or a mix of both) should be based on a high resolution slope stability analysis and a risk
assessment as mentioned by Peter.
- Radiata pine is not always the highest sequesterer of carbon. It depends where in the
country you’re looking. In many parts of the country exotic hardwoods such as Eucalyptus will
store carbon at a faster rate (and produce more valuable timber).
- The comparison of NZ harvesting with German (or most European) forestry is not strictly
comparing apples with apples. There are substantial government subsidies and support for
forestry in Europe and, most importantly, they only expect an Internal Rate of Return of 3% there
whereas we (greedy) Kiwis and overseas plantation owners expect 6%-8% IRR.
Tomorrow’s Forests Ltd