FIGHTING THE SAND.

Manawatu Herald, Volume XLIV, Issue 2430, 18 May 1922, Page 4

FIGHTING THE SAND.

EXPERIMENTS ON THIS COAST.

At the beginning of last winter the Government, partly actuated by a desire to relieve unemployment, started operations among the sand dunes about three miles south of Tangimoana, the little seaside resort at the mouth of the Rangitikei Raver, the idea being to make experiments with a view of finding an effective and economical method of holding the sand so that tree-plan-ting on an extensive scale could be undertaken. The Forestry Department was entrusted with the business, and during the winter months 26 men were given employment at the camp.

At the present time only six men axe on the job, but sufficient has been done to give the Department a guide for future operations. As has already been indicated the aim of the Forestry Department experts is to create a forest belt that will in time extend to cover the whole sand dune area, the trees grown to be of such variety as will come into profit in the shortest possible time and yield supplies of timber suitable to the country’s requirements. The value of such work may be gauged from the fact that should the -experiment, succeed it is hoped that in forty years’ time this forest will be able to support comfortably one family to every hundred acres. Up to the present the main concern of the men on the job has been to find a cheap and efficient method of holding the sand. Anyone who has been among the dunes along the coast will have noticed that there is no uniformity in the endless chain stretching away north and south; that each mound ofj sand is separate from the next by a gully, which the incessant winds from the sea, rush' inland. Through these channels the winds carry loose sand, and the Department’s experts contend that before any effective work can be done the channels must be closed and an unbroken front presented to the enemy. When such a barrier is erected (It is planted with marram and other grasses, which will hold the sand fast, then behind this rampart the forest. will spring up to form a further barrier between sand and land, and produce wealth for for the people. This being the policy adopted, the aim has been to hit upon an economical way of blocking the wind channels. Drifting sand has many curious characteristics, so much so that it would almost appear to be invested with intelligence, and the problem of .Mr Stride and. his men have been busy with a variety of devices, some of them showing much ingenuity, and_ a considerable measure of success has been achieved. In every wind-channel over a given area —about a mile in length —barriers have been erected, the idea being not so much to bar absolutely the progress of the sand as to steady the wind and thereby compel it to drop its destructive burden. Fences of various kinds have been erected which are designed to act as drags on the wind. A complete hairier would merely force the wind at increased volocity round the ends of the obstruction, where it would form another channel, and nothing would be gained thereby. But with plenty of open spaces the speed of the wind is merely reduced, and it thereby loses its hold of the sand, which curiously enough, falls not on. the seaward side but to the landward of the obstruction. , With a •succession of heavy winds enormous quantities of sand are carried and the result is that the wind-channels fill rapidly, the obstructions being raised from time to time as necessary. Naturally the chief concern of the men on the job is to find the cheapest material for the barriers. The beaches abound in driftwood, and it was thought this would be an economical barrier, but the labourcost proved to be a considerable factor. Manuka, where handy would probably be cheaper than anything else and is certainly .most ■effective. But at the works under review, Mr Strike appears to have found a new use for flax, which is now being extensively used. It makes an excellent filter for the wind: is decidedly cheap, and can lie pulled out and raised as the sand barrier grows upwards. So far very little has been done in the way of planting, but it is hoped that in the season now due that large nurseries of marram will be planted behind the sand barriers and from these sufficient plants will be obtained to hold the rampart of sand which is gradually rising between sea. and land. Another grass that is found to be most effective is the silver" grass —a New Zealand native—marram lining an imported plant from the Baltic Coast, where it is said to have been in use on sand dunes for over two hundred years. The future of these experiments—fraught with such important issues for this district —will tie watched with keen interest.