The Auckland University of Technology Living Laboratories project is all about investigating how best to grow back native forest. At Pourewa creek, this collaboration between AUT and Ngāti Whātua Ōrākei involves planting blocks with different nursery plants and measuring individual tree growth and biodiversity indicators over time. They hope to figure out the recipe to cheaper and faster regeneration of native bush.

We know that trees can help us sequester carbon and get us to our climate change carbon goals. We also know that native forests are spaces that can help native biodiversity.

So why are people lining up to plant large areas with pinus radiata instead of native ngahere?

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The answer is simple - many exotics, like pine, are lower risk, cheaper and faster to grow, sequestering more carbon in the short term.

Under the New Zealand Emissions Trading Scheme businesses have to surrender one emissions unit - one New Zealand unit - to the Government for each tonne of emissions they emit. Foresters who plant trees that absorb carbon earn units from the government that they can sell.

In a policy framework where carbon sequestration is valued in isolation of other benefits, native trees are at a disadvantage.

This is what the Auckland University of Technology (AUT) Living Laboratories project wants to help address.

It's a set of planting experiments designed to investigate the quickest, cheapest, most risk-free way of restoring native forests in a farmland context, as well as monitoring the ecosystem benefits such forest provides as it grows.

Left to its own devices much of the farmland in Aotearoa would, over time, return to native forest.

First, the pioneer plants would appear - for example, kānuka, mānuka, karamū, māhoe. Able to deal with drier, hotter conditions in open areas, eventually they would provide the cover for the next round of trees to move in - maybe pūriri, rimu, rātā, tōtara. Brought by seeds dispersed by wind or bird, maybe from the native bush nearby.

But this takes time. A lot of time.

Across three sites, the AUT Living Laboratory project is investigating different ways of fast-forwarding this natural plant succession to get to the later, bigger trees earlier.

The first site is on Ngāti Whātua Ōrākei land at Pourewa, where they are revegetating 2.2 hectares and comparing kānuka pioneer plants versus a mixed group of māhoe, ngaio, tarata and karamū…

Go to this episode on rnz.co.nz for more details