Afforestation Of Wanganui River Valley Areas

Wanganui Chronicle, 19 February 1949, Page 8

Afforestation Of Wanganui River Valley Areas

Many Problems \To Consider In Any Worthwhile Scheme (By J.SA.)

Many problems arise in regard to afforestation of the Wanganui River Valley, attention having been directed Io them by the scheme brought before the Chamber of Commerce recently by the president (Mr. N. M. Izard). The price governing all commodities is based in part on the cost of marketing them. Transport is one of the biggest problems to be overcome in setting down areas to commercial forests. Most of the back country of New Zealand is steep, and served by class 2 or class 3 roads, with limitation on axle loads.

To transport logs to a sawmill. ! it is essential to have well formed roads which can stand heavy i trucks and trailers constantly running on them. The hill roads of the Wanganui River do not fulfil these conditions. In winter they are subject to slipping. Their surfaces are often only partly formed, and upkeep would be a greater drain on county funds than the value of the timber extracted.

Tha alternative is river transport by either raft or barge. Barg have the benefits that they can be powered with motors, but to offset this is the handling of green , timber on to them. Additional benefits of this method are that there are no free logs floating down the river, or stray logs grounded in sandbanks during low water periods. Rafts are formed of many logs joined together, chained to a barge as a traction and steering mechanism to tow them to a definite slackwater whence they are lifted direct to the mill.

Overseas, where logs are floated to a mill for conversion, advantage is often taken of the spring freshes to float the logs willy nilly to the sea where they are snared and moored. This last method is unsuitable for Wanganui river. There are river steamers that have to have navigable channels and Port shipping at the harbour. In the lower reaches there are the many types of pleasure craft which can be easily damaged. The winding course of the river predisposes to giounding with subsequent silting, and danger to river traffic. The scenic attractions of Wanganui River must be preserved, and this means a permanent clear channel for ■ river boats. So the cheapest and most. efficient transport will be by steering , barges with booms of logs, or failing this, laden targes The choice will be governed by two major facts in opposition, that (1, a raft of logs will ! require less oepth of water than a! laden barge, but (2) a raft will be . more likely to leave stray logs in the I river bed. ‘ MILL IN THE CITY There is little possibility of establishing a suitable conversion plant in the upper reaches of the river. A mill in the Wanganui City area must be considered as the only feasible solution. This needs a stillwater as a holding area for logs brought down by the barges from which they can be transferred to the mill, with the mill on the river bank also. No doubt such an area can be found for this. It would involve a through investigation of the lower reaches of the river, taking into account the permanent effect of afforestation of the upper river, on the river flow, depth, and flooding. Observations would have to be made over several years of the flow of the river at all points as high commercial afforestation is extended, so that decision can be made as to whether or not locks are necessary to maintain a sufficient channel at all places. The site of the mill must be convenient to the future railway development of Wanganui. Again, the permanent effects of afforestation of the bare hills would mean an altered flow. Rivers whose watershed is barren steep hills have a rapid flooding after rain. Afforested watersheds help prevent primary floods, and spread the run-off over several weeks. Consequently we would expect less flooding in winter and a deeper channel in summer when the river is at its lowest. This alone may obviate any need for locks. It would be ten years before even thinnings were transported, and in that time the river would have started to define its permanent flow rhythm. Purely from the costing aspect, steep country is unsuitable for commercial forestry. It is expensive and difficult to log timber on steep faces. On flats it is cheap. The margin between mere expense and loss is small. This is a difficult problem, since it tends to involve not only the steep areas themselves, but also any smaller areas of lesser slope, that are not fully economic units themselves, but taken with the steep areas, the whole is. SUSTAINED YIELD AND CLEAR CUTTING A forest worked on the sustained yield principle will produce a continuous crop of trees that are harvested piecemeal as they mature, and is not cut over as a single unit for conversion. Such forests are typical of Germany especially, where for generations timber has been grown, milled, and replanted* without any break in the process. N.Z. is a classic example of clear cutting (often with the use of fire) leaving hillsides bare and open to erosion. Sustained yield is the only method of afforesting a river valley so that the natural history of the area is not upset at any time by milling operations. But the steepest areas do'not lend themselves so readily to this form of cutting, and modifications of clear cutting would have to be introduced to transport logs to the river economically without damaging the still standing and growing trees. The contour of the country, running as it does, some miles back from the river in places, is another difficulty in sustained yield approach to felling. But this should not deter the attempt, for the benefits of a permanent cover of trees cannot be measured in money alone as expressed in the value of the crop. There is a problem to be overcome, but a judicious mixture of species, and pure sustained yield where the country is suitable with also modified clear cutting policy on other areas with immediate replanting would overcome it. SPECIES SUITABLE FOR PLANTING While it is admitted that many of our native species are excellent timbers for almost any use, they are not

suitable in general for afforestation. Reliance will have to be placed on exotics as the mainstay of operations. The steeper faces can well be abandoned to native bush as many are now, and this forms an erosion resistant covering to the hills. But it cannot be marketed with the profit that so many exotics can be. While Pinus comes to mind as a species that thrives in this country, we should not be led away by the success of the enormous artificial plantations about Taupo area into thinking that it is the only suitable species. It is a quick maturing tree that gives an excellent bulk and quality of wood suitable for many purposes, especially when treated. But our lack in N.Z. is hardwoods also. Of the softwoods. Sequoia sempervirens and Douglas fir are eminently suitable amongst others for planting, though their maturity rate is parlously slow. They can be cut young, but at the expense of quality and bulk in their timber. But the rate of maturity need not be considered so greatly under these circumstances. Leaving the area in standing bush for a hundred years would be excellent policy, for in the meantime there would still be income from the area and employment for many people. Erosion would have stopped almost entirely, and with the end of erosion, the port of Wanganui would again be a vital centre. The need of N.Z. lies more in hardwoods for current plantings than for more softwoods, for the enormous plantings already made, and planned for the future will be sufficient for our needs. Hardwoods at the present time must be imported from Australia and overseas, using shipping space and money better devoted to other things. Many species of the hardwoods can be utilised in New Zealand in the furniture trades, as plywood veneers, in building, and finely figured timber could well be exported to other countries. There is another side to their use also. No one who has travelled through the miles of pine plantations can but be depressed by their samemess. On the other hand, the hard--1 woods have definite individuality and variety at all seasons. Diversity of foliage, flowers, autumn tints that can act as a foil to the sombre dark green of the pines enhancing the tourist attractiveness of our already attractive river.

With forethought, species such as the varieties of nuts could be included in small bulk stands to provide new adventures in eating and a more varied diet for the national market. Here is a perennial source of income—seasonal admittedly—but of value equal to that of timber, or even higher. Surveys of the whole area will show where plantations of exotic hardwoods will succeed, or where experimental plantings can be made, not only of birch, beech oak, walnut, elm, eucalypts. but also other woods that have not necessarily yet been planted in New Zealand, except as ornamental species. In short, while the major plantings would be of species of established suitability for the area, other parts of it can be treated as an experimental area for other desirable species which may or may not succeed. If they are a failure, the area can again be planted over with successful species. While the failure would cost a certain amount of money, it would be more than compensated for in the value of the successful plantings of the most desirable species that are now being cut out overseas with little hope of replacement complete enough to offset the present loss. Despite the woeful forecasts of the electrical age supporters, wood is finding greater and greater use as industrial chemistry and the chemistry of wood advances to the end of ultimate utilisation without waste. PRESENT SETTLERS AND AFFOREST A TION. Such an afforestation scheme must be done as thoroughly as is possible. Every hillside and every valley should be planted if it will grow timber. Farms, at present uneconomic, could be purchased by a board of trustees, or rented. Their owners often would find congenial employment as foresters living often in their present homes, but more often as small communities of people all employed oi the same problem. A township of twenty houses, a store and a community centre would be a vast increase in the living conditions of the back country family. There woqld be most of the facilities of the larger towns, as access to the city would be daily by the various barges travelling up and down. On a community basis, there are many areas, not necessarily on the Wanganui watershed, but also on the Waitolara watershed, that could make such centres self-support-ing as regards meat, dairy produce, vegetables, while other goods can be transported by. road or river as is desirable. It has been shown that the Maori takes easily to the timber industry. His tribal way of life, for the Maori is a gregarious man, could he well continued, and isolated families brought closer together to the advantage of better living conditions that a community can supply, and schools for children. It is too often thought that a forest is merely planted and left alone till it is felled. On the contrary, there is work for foresters right from the day of planting till the final logging, and as this area will he in nerpetual forest, the work of re-establishment of cutover areas will continue all the time. So. too continues the work of general management--periodical thinnings and other routine The mills would absorb some scores of workers and technicians in the city. New industries arising from ultimate utilisation of the previously wasted wood would come and bring further labour and population in their train. With erosion as the major cause of port troubles in Wanganui under control, coastal shipping would find Wanganui a valuable port of call instead of as at present, a necessary nuisance. Planting, nurseries for raising stocks, and general forestry operations will provide work for hundreds

of employees; utilisation of the timber produced will provide employment. for. at least two hundred more families. Probably ultimately, more than two thousand families would he supported directly frotm the limber resources of the river valley, and some more thousands in part from secondary effects of this planting. Measured in these, terms, the project is amply justified, and support should be obtained through urgency of public recognition of its value. The Chamber of Commerce who originated this scheme must be congratulated on their foresight and a vare-

I iiess of its real value to the country [ as a-wholc, and to Wanganui especiali ly. No other town of comparative size in New Zealand has so acute a problem as Wanganui has in the river watershed o!’ little farming value, that is eroding annually and si’iirig the harbour, which in turn takes in- , dustry out of the town, and with it, the population necessary for the continued well being of the district. The scheme is feasible. It is urgent. It remains only for the .general citizen, the man in the street, for you and me to get on with it and make it a reality.