Answer is blowin' in the wind

By Meg Liptrot

Trees felled by storm are a chance for creative recycling, writes Meg Liptrot.

A huge eucalyptus was one of the casualties of the ferocious winds that lashed Auckland. Photo / Meg Liptrott
A huge eucalyptus was one of the casualties of the ferocious winds that lashed Auckland. Photo / Meg Liptrott

Arborists certainly had a windfall after that mighty storm blew through the country and winds reached an impressive 170km/h in parts of the North Island.

Our house is perched on a ridge and felt like it would fly away that night. I was up checking Civil Defence and Metservice warnings at 3am when it felt like we were surrounded by a hurricane.

A waxing moon illuminated our neighbour's three palm trees, which were blowing sideways at an unnatural angle, looking like they were in cyclone footage from the tropics.

An eery calm settled the next morning. Heading to work I felt justified in my overnight concern. It looked like a food processor had emptied its contents on the road as leaves and detritus littered the streets. Heading down Motions Rd past the Auckland Zoo my jaw dropped as I spotted a fallen giant eucalyptus about the length of a bendy bus bridging the stream. Reaching Great North Rd, metal railings were mangled by the weight of a huge tree.

So what should we do with all this bounty?

It seems such a waste to chip huge trees into mulch. The more I thought about it the more I felt we could make use of millable trees in a better way. The sentiment was echoed by colleagues and friends who wondered why this timber couldn't be used more productively.

Portable sawmills don't need much space.
Portable sawmills don't need much space.

Timber and garden beds

The decking on our veranda is built with untreated quarter-sawn tongue-and-groove Eucalyptus saligna; the kitchen bench and cabinet doors are made of E. pilularis; and our book shelves are poplar.

Our raised vege beds are built with macrocarpa. A friend of ours had two giant eucalypts fall at either end of his street in Herne Bay and was equally perplexed as to why the timber couldn't be used.

Clearly the council's priority is to clear the hazard and unblock the road where public safety is a concern. But in other areas which are out of the way, such as parks, the process could be rethought.

Portable sawmills don't need much space and, after speaking to a couple of portable sawmill companies at Fieldays last weekend, it seemed there was no real reason for not giving it a go. It costs about $180 to $260 a cubic metre to mill a tree, depending what plank widths you want.

Structural timber requires strength testing, which is an additional cost that might put people off.

In an unofficial response, an Auckland Council arborist and landscape adviser said the council had investigated using such trees for timber but health and safety problems and the clean-up required after milling had been difficult to justify in terms of cost.

Sometimes they give timber to woodturners and have had a few trees milled by outside parties. They do make use of macrocarpa, but eucalypts are tricky and only four species are viable for milling. He said the timber product people bought and the trees in our parks were "two very different things". Although most of the fallen trees might provide low-grade timber, I think they would make good sleepers. And many schools, marae and community gardens would appreciate sustainable, untreated timber for building raised vege beds. In future it might be worth planting millable species in parks.

Firewood

Many chilly Housing NZ and pensioner flats could do with this resource for firewood. Windfall logs require sorting, cutting and splitting and should be left for a year to dry.

Although fires create visible smoke and don't seem like a "green" way to heat a house, choosing an efficient woodburner and burning plantation-grown dried timber is a good option for sustainable heating.

Mulch, sawdust and compost

The council arborist said it might seem odd that mulch is of a much greater value than the timber when it is recycled into parks to be used suppressing weeds and as mulch around newly planted trees.

He said it probably had a "net positive in terms of carbon sequestration" when it was recirculated into the park. Get in touch with your local arborists if you want mulch for your garden.

If milling trees in situ was given another go by council contractors there would be opportunities for community micro-enterprises to help with clean-ups.

Demand for untreated sawdust will increase when Auckland Council's food waste separation comes into play in 2016.

Homeowners will want to save money by putting food waste through worm-bins or compost bins, and untreated sawdust is one of the easiest carbon sources to sprinkle over food scraps to help reduce odour and make perfect compost.

- Herald on Sunday

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