Natives grow more slowly than exotics and so sequester less carbon in the same time frame. But if not logged, that carbon is deemed permanently stored, not just for the typical 30-year crop rotation of pines. Natives are indigenous to the New Zealand environment. Our unique bird species evolved in native forests and are perfectly adapted to them - provided we can manage introduced pests.
Native forests are also are better at soil stabilisation and sediment retention especially if they are grown as permanent forests. Moreover they are a natural part of our New Zealand landscape, diverse in form and shades of green. They look like they belong and evoke strong feelings of New Zealandness in people. They are taonga. We value them.
There are commercial opportunities from planted native forests too. We could grow some specifically for the additional benefits of high quality, high value timber production and the jobs that go with that. Provided logging is selective, low impact (such as by helicopter) and limited to those specific new forests, why not?
Other benefits of new native forests include honey production, a burgeoning industry with sizeable potential earnings.
A lot of highly marginal land, such as on the east coast north of Gisborne, is better suited to permanent forests because of the steepness of the terrain and stability concerns after logging. Much marginal Maori land is waiting for this kind of investment with its employment opportunities for local communities and the resonance native forests have with kaitiakitanga values. Some land inappropriately converted to intensive dairying that's causing local pollution could well be suitable for reconversion to indigenous forests.
There are lots of opportunities here, all of which bring jobs, so the idea of planting a billion trees over 10 years is sound.
My big concern is that the machinery of government is not well geared to consider natives as a large portion of the billion. To date, officials haven't devised an effective approach that values the multiple benefits of native forests. The Emissions Trading Scheme, the Permanent Forests Sinks Initiative and the Afforestation Grant Scheme all have flaws that are well recognised by the forestry sector. None of them take an holistic view of all of the benefits of tree planting.
My suggestion is that government should develop a new, properly funded incentives programme. It should acknowledge the carbon, biodiversity, soil, landscape and freshwater benefits of native plantings. This idea should form part of an overall strategy aimed at getting the best possible outcome for New Zealand from what could be a massive investment in restoring some of our lost natural forests.
In many respects, New Zealand is at a crossroads in its history. It's as if we are transitioning out of the exploitative, pioneering phase into a more progressive and forward-looking era in which we recognise the need for much better environmental outcomes. That's the big take-out from the election result, in which environmental values assumed much greater prominence than ever before.
Accepting the billion trees commitment and developing a carefully thought-out strategy aimed at maximising all the benefits for New Zealand is needed. We need good science, awareness of cultural values and clear direction-setting before rushing ahead. I suspect we need both pines and natives and much more of the latter, but let's work out that balance.