PINUS INSIGNIS PLANTATION

Nelson Evening Mail, Volume LXX, 20 June 1936, Page 5

PINUS INSIGNIS PLANTATION

(To The Editor) Sir, —Last September, a correspondent “Horned Tailed Borer” ashed for information about Pinits Insignis (1) on immature trees for cases, (2) maturity of or the economic period for converting into timber, (3) risk of fire, (4) close planting, (5) and thinning by “taking out all trees over 9 inches.” : As the Insignis is becoming of such value to the district if rightly handled, but if wrongly then there is disaster ahead, it is high time to take stock of the situation and I submit the following remarks hoping more intelligent interest will be taken. Immature trees are quite suitable for cases in spite of the experience of fruit growers with soft timber that Will not hold the nails and the tendency to go mouldy and black. The remedy is to treat the same as the hemlock from which the Canadian cases are made; kiln dry and shrink hard enough to give a firm white case. But the present system of milling will have to be altered to produce . this. White hinau I saw peeled at Bryant and May’s match factory in , Wellington started to mould under 24 hours, but drying stopped it. j The economic time to convert into timber varies in different localities, but the following came under my ob- | servation and is typical of the usual practice. Two trees in close proximi- , ty were felled, one 30 years old ma- ; ture and one 13 years immature. It l measured up 150 super, feet which at '2s returned to the grower two pence | per year. I then calculated the meaj surements on the supposition that it | would have grown as fast as the mature tree having more room and j found that if given five years longer jit would have returned four pence | per year for 23 years. Few of your | readers will understand this but the i reason is lhat the annual increment I at even growth is in proportion to the ! diameter. If you double the diameter I you double the annual increment with i the increase in height extra. Simi- ' larly an over mature tree was Celled ! at 57 years for a return of under nine j pence per year. If it had been felled !at 37 years, the year of maximum growth, it should have returned over one shilling per year, but the slow growth the last 20 years was eating into the value of the fast period. As all farming returns are calculated as per acre, be it sheep or crop, so with forestry. Trees can be thinned to get the maximum increment per tree but a point is reached and can be calculated when the return per tree is increasing but the increment per acre commences to decrease. This is the time for economic conve'.'sion into timber. The trees will not be very large at this stage, consequently sawmill plants must be designed accordingly. I should surmise that this is the Swedish forestry policy. Of course, if larger trees bring a higher royalty then the economic point will come later on. The above remarks are on a fixed royalty scale. To grow trees for an annual return of two pence per year is disastrous, yet that tree was profitable to everyone but the grower. The factors that control profit outside the royalty are the annual increment per acre and the life of the tree. To thin insignis by removing the larger trees is wrong in principle because of its short life. The smaller trees have years of their life thrown away. Their annual increment is too slow at the start and they have not the size to put it upon nearing the finish.

This is why a number of closeplanted neglected plantations are already doomed and yet if a fire got in the owners would claim compensation on the supposition that they would produce tens of thousands of super feet of timber per acre, whereas they will not produce decent firewood. Nature is endeavouring to remedy the neglect and do the thinning by means of the horn-tailed borer we interfere by introducing a parasite. The fire risk, especially with neglected plantations, is causing concern to farmers adjoining and a remit was brought forward at last Farmers’ Union Conference that plantation owners should maintain two chain firebreaks around the plantations. I would suggest the best method is to plant right up to the boundary, maintain a cleared portion under the trees, have the fire line on the farm land adjoining and compensate the farmer by allowing him the two outside rows of trees. You have by this method mutual interest. Those two rows get their nutriment from the farm land in any case, and the plantation owner can utilise farm practice be it crop or stocking for fire prevention. Another method is for both parties to engage expert supervision to control burning oft’. When a plantation is deliberately neglected the farmer should get a report made on the lines of the information contained in this letter as a precautionary measure. It should count for more than a report made afterwards in support of a claim for damage by fire. Then again the fire hazard is changing in those plantations where work is proceeding. With decayed refuse several chains of firebreak will be rerequired to hold fire that could be stopped by one chain before any rotton wood was about; and in fire-fight-ing a different, more deadly, smoke will have to be contended with. The fire menace may appear to be of less consequence, the public being more careful, realising the value of the plantations to the community; but the fact must also be recognised that many land owners are scared stiff to allow a fire to start on their property.

Your correspondent mentioned too close planting of pines. He is quite right but close planting was the policy of the Forestry Department. Why, I do not know. The one and only infallible guide in forestry is nature in our own natural forests and the same laws hold good for the exotics. I have always contended for mixed planting scientifically planned so that the inferior species are suppressed in turn, the final dominant trees finishing at 20ft spacing if growing full life trees. It may be less if going for case timber. Thinning this wav as in our native forests automatic. In my opinion this is tl*e only way to produce clear grade timber. There is proof of this method in this district but even to-day pure stands are being put in with the inevitable struggle for the survival of the fittest from a level start, and amongst one species with loss in annual increment, susceptibility to disease and parasites. The mixed planting gives healthier trees. There is an exception to the above: that is, where the plantation is of natural regeneration. Here nature does the job to a degree because EVVMAN'S Comfortable Cadillac Motor Service runs Daily (Sunday excepted) to Christchurch.

of the irregular start amongst the seedlings and a totally different, type of pine is produced to the hand-plant-ed. The reason must be the natural root system but such a plantation is almost fireproof. I state definitely that the future of the pine plantations is in natural regeneration as proven on the Kainui plantation and not replanting by hand as is claimed by a forestry expert. It is a curious thing that the tree thinned eft by nature stops growing two years before the leaves turn yellow. The horn-tail-ed borer knows and attacks that tree while still green. By mixing deciduous trees with the pines the fire risk can be practically eliminated, particularly with sycamore. This tree will not only break a crown fire but is the only one I know of that will in this district check a ground fire as the ground in summer has a green cover from the suppressed seedlings that grow under the parent trees. The heavy annual fall of leaves rots down the pine needles and letting in the sun, rain, wind and frost weathers off the dead limbs on the pine trunks. It is good firewood, and I believe will make good the deficiency in the present all-pinus ir-signis apple case. A little more experiment will show if it will.

Coming now to (he mechanical side, I would suggest that an efficient pine case mill should have no slabs, no sawdust, no shavings and should buy logs by weight before plantation owneis can expect a profit. My observation is that the plantations, like other primary productions, hove to take what is left over, after all else is paid, for financial returns. But there is no question as to their value to the community. The problem to-day is not fire, but efficient conversion. Organisation appears necessary amongst the owners if this community-value is to be maintained. Already planting has been burnt to make way for sheep and some owners are just wondering what they are going to do, particu’arly those owners who have been keeping tab on costs. —I am, etc., J. P. PROUSE. Wakefield, 15th June.