Ugly — but windrow is new philosophy in forestry

Press, 30 August 1978, Page 23

Ugly — but windrow is new philosophy in forestry

Mechanisation is the key to more economic and productive forestry in New Zealand. In the second article of a series, DERRICK ROONEY looks at windrowing — a controversial subject among ecologists.

If the history of forestry in Canterbury can be said to be based on the philosophy of the windthrow, the future can equally be said to be based on the philosophy of the windrow. These lines of stumps and non-millable logs, pushed up by giant bulldozers, are admittedly ecologically undesirable as well as ugly. But they are the only practical solution to the problem of clearing

milled areas for replanting. In the Selwyn Plantation Board’s holdings at Burnham, I saw, side by side, plots which had been prepared for replanting by a variety of methods: by windrowing, by hand planting among the debris of the previous crop, by miniswindrowing, and by, windrowing and burning. Of all these, the area that had been windrowed,

then burnt over, was visually the least offensive. But burning is hazardous in Canterbury, and it has no economic advantage to counterbalance the danger. Mechanisation is the key. If the forests can be planted so that access for machines is easier, the costs of both maintenance and harvesting are reduced, and profit is increased — making more money available to be put back into forestry.

Replanting without the bulldozer may be ecologically more desirable, in that it is closer to the natural process of growth, decay, and regeneration; but economically it is disastrous. A graphic example of this is'a section of windthrown plantation in Steele’s Road, near Te Pi j rita. This is an area that was milled over years ago, and allowed to regenerate naturally. The area suffered exten-

sive damage in 1975, and logs are still being recovered from it. It is a tangled mess — difficult of access and dangerous to work. Many of the trees are poor specimens, and the yield of millable logs is only 20 to 30 per cent, compared with as much as 90 per cent for a wellplanned forest. The other 70 per cent is not a total loss, of course; many of the logs that cannot be milled can be converted to woodchips, and some of the smaller logs will make poles or posts. But the difficulties facing the contractors there are reflected in the attitude of the board’s staff towards replanting. This is, in effect, an acceptance that eventually, all pine plantations will be blown over. Well, maybe not all; but Bill Studholme, the board’s secreta r y-superintendent, is only half joking when he says that the windrows and the lines of trees now are all oriented towards the nor-west, so that when the pines blow over they will do so in orderly fashion. Unhappily, it is true that forestry in Canterbury does not have a happy history. Something over 90 per cent of the total amount of timber harvested by the Selwyn Plantation Board has been windthrown timber. Its forests were damaged by major nor-west windstorms in 1914, 1930, 1945, and 1956, before the big blow of 1975. When the 1975 blow struck, the lessons learned from the earlier gales were still being put into effect. In 1945, the nor-wester blew down between 60 and 70 per cent of the trees planted before 1900 in Malvern County. But the plantation board came out of it reasonably well, for it lost only 500 hectares, 10 per cent of its standing timber, and of this all but 5 per cent was recovered over the next six years. The 1975 blow flattened 2500 hectares of Selwyn Plantation Board forest — not much less than half

its total plantings, and most of it choice radiata pine ready or nearly ready for milling. No official estimate of the damage is available, but after touring the plantations I would hazard an inspired guess, and say the loss in the windblown areas was 90 per cent. But a very large amount of this timber has been salvaged, and much of it has gone to Japan. The long-term effect of the 1975 blow will be a shortage of radiata pine timber in Canterbury, but whether this comes sooner or later will depend on the behaviour of the economy. Canterbury has been hit harder by the recession than other areas, and the demand for timber is certainly not booming. If industry picks up and building increases, the effect of the big blow will be felt throughout the Canterbury timber industry by 1980 or 1981, according to Bill Studholme. But if the economic recovery is slow, and indications are that it will be, the shortage may be five or 10 years off, and by then trees planted in the early sixties will be maturing. A more serious problem for the Selwyn Plantation Board, and other ,b>g afforestation organisations, than shortage of saleable trees is shortage of labour, and this is one of the major reasons for mechanisation down in the forest. Increasingly, it is difficult to find — and hold — men willing to do the arduous and frankly boring tasks of pruning and planting. All the Selwyn Plantation Board’s planting, except for spot planting in gaps in the windrows, is now done by machine. This machine, tractor drawn, is a modified version of a cabbage planter, with a steel foot to clear the debris out of the way, followed by a metal shoe that drills a channel and drops seedlings into it at two-metre intervals. At the back a pair of angled wheels push the

soil over the roots of the newly planted trees and leave the rows of young pines in small channels, so that they can get the full benefit from dew, and from every shower that falls. The team of workers who use the machine — two the day I saw them in action, but usually three — have a daily planting quota of 8000 trees, and share a bonus for every tree planted above that figure. There is good reason for the bonus: the board has only two tree-planters, and its target this year is to put 1500 acres down in trees. There is little time to waste.

Short-term cash savings are not the primary consideration here, though. The major saving does not come until later, when the trees are growing — as they do grow when planted mechanically. The survival rate for trees planted by machine is better than 90 per cent, whereas hand-planted trees seldom do better than 70 per cent. And there is some shrewd industrial psychology at work, too; the board has found that when it gives its men machines to work with they do their jobs better and stay at them longer. (Tomorrow: What does the future hold for forestry in Canterbury.)