10 April 1985 Coppice to be established at Lincoln College

Lincoln College is to have a coppice a small wood or thicket of trees to be cut back regularly for firewood or for furniture making that will be the first established in the South Island and one of few in New Zealand .

The coppice is being established to mark the work of Bill Brandenburg who retired as a specialist advisory officer in greenhouse technology last year after 30 years with MAF and the New Zealand Department of Agriculture.

Money to establish the coppice is coming from the Canterbury Growers Society, and a hectare of land has been set aside in the Lincoln College Research area.

A coppice is an age-old method of ensuring a continuing supply of wood from growing trees .

Trees for a coppice are grown to planting size in a nursery, planted out, and when well established are cut down to just above ground level.

The regrowing tree then develops several long straight stems with a few small side branches, growing much faster than a tree left to grow in the ordinary way.

This faster growth comes about because, after cutting, the root capacity of the tree is far greater than the part of the tree still above ground .

A block of trees regularly cut down to just above the ground is a coppice, and produces wood faster than by any other method.

Some trees, such as willow, can be cut every year i; oak, ash, sycamore, sweet chestnut, maple and beech are cut on a longer rotation - up to nine years.

The intention is to plant the European species of oak, ash, sweet chestnut, and beech, New Zealand beech, sycamore and elm at the college.

Initially, the trees will be planted about 100 to the hectare at 10-metre by 10-metre spacing .

Three disciplines  - horticulture, entomology and biological husbandry -  will come together in the coppice project.

A coppice is almost self sustaining as other species of trees and shrubs are planted among the main trees.

These other trees and shrubs, such as wattle, tree lucerne and robinia, are known as nurse species.

These nurse species provide shelter for the growing trees, fix nitrogen in the soil, give sanctuary to predators for pest control and maintain honey supply .

Coppices also provide shelter for crops such as cucumber and pumpkin, and at other times crops such as onions can be grown when the trees have been cut back.

This variable shelter is useful for growing these other crops.

Entomologists at the college will be able to research predator insects, those in biological husbandry can study the balance of trees, crops and insects, and horticulturists can observe tree growth and the relation to other nearby horticultural crops.

Berry-bearing nurse species of trees and shrubs are expected to attract birds away from grapes in the horticultural research area.

Presently scaring devices and poison are used to keep birds from eating grapes on experimental vines.

Wood from coppice trees is used for chair and table legs in furniture making, tool handles, poles and fence posts .

Trees in short-rotation coppices can provide osiers from willow trees for basket making, or tan bark from oaks.

Longer-rotation trees, ash, elm, maple, sycamore and beech, can be used in making
bentwood chairs .

Eight-year rotation logs can be used for pulp and paper making, or for firewood.

Traditionally in Britain, Europe and America and other countries coppice wood has been used for firewood.

Woodmen used to gather twigs on short rotation from coppice trees and tie these together in bundles called faggots.

These faggots were used for bakers oven and for stills.

Today some short-rotation copses in Britain are mechanically harvested to produce compressed faggots for modern log fires.

Using coppice wood for firewood is very important as New Zealand faces firewood shortages as more and more wood-burning fires are installed.

The only coppices established in New Zealand so far have been set up by the Forest Service for experiments in producing firewood.

The Lincoln College coppice will also be used for research and experimentation.

Some sweet chestnut trees from Italy have already been promised for the college coppice.

Wood from these trees can be used untreated for poles.

Eucalyptus trees will also be grown to provide quick production of firewood on a four-year rotation.

Those establishing the coppice are also hoping for donations of trees, particularly from nurseries.

Around this time of the year nurseries are choosing trees, and those graded out as being unsuitable for ordinary growing may well be suitable for use in the coppice.

Trees lacking apical dominance - too little growth at the top - or those with far too many side branches can do well in a coppice.

Such trees can develop with good tops and straight growth in a coppice.

Coppice trees are cut down to about 25 to 30 centimetres above ground level, with steeply-sloping cuts to prevent water penetration and stump rotting.

Usually coppice trees are cut down in rotation from two years to eight years .

European trees are seen as being the best for coppicing in New Zealand. Fast-growing willows, poplars and maples are the best for quick production.

Slower-growing trees are ash, beech, oak, robinias, alders and some prunus and malus species.

Some trees, such as hazels, can be cropped for nuts and coppiced, while other trees can be coppiced and the cut-off growth used for stock food.

Coppicing holds root spread under control after the first cut, so there is no competition with cultivated crops.

So far research has shown no native trees as being suitable for coppicing, because most are related to conifers which will not regrow after the main stem has been cut.

Coppices are ideal wild-life sanctuaries, as well as looking interesting on the landscape.

Coppicing can be quite labour intensive, but with. careful management this need not be so .

Further information from Dr David Jackson, Department of Horticulture, Lincoln College