A NEW ZEALAND SAHARA.

Otago Witness, Issue 3619, 24 July 1923, Page 60

A NEW ZEALAND SAHARA.

By

F. C. Attwood.

No one need travel to Africa or Central Australia to gain the experience of standing amidst an apparently limitless waste of desert sand. Such an area can be found within easy walking distance cf the rich grassy river flats of Southern Kaipara. In fact, it cannot be avoided in proceeding coastwards from the railway line; but usually the first impact with the sand is somewhat of a shock. More than five miles from the sea the hinterland of the farms will be found abruptly terminating in a steep slope of loose sand, looking as fresh and as out of place, as it pours down on the green pasture, as if tipped there the night before. Indeed, if the wind has been a severe westerly, several feet of further encroachment may have taken place during the preceding 24 hours. Every ‘foot of turf submerged is lost for all time, for the advancing dune averages upwards of 100 ft in height. Here and there clumps of trees or belts of scrub appear to check the invasion, but how ineffectually one may guess from the sight of the topmost twigs of large puriri trees, seeping, white and dead, through the piling drift. Here and there lakelets are formed, through the choking up of valleys, and the seeping water in its escape carries with it the restless sand, to find a lodgment in the Kaipara River, to the detriment of drainage and navigation. The ascent cf the newly -formed sand tip is somewhat arduous, but once the top is gained the going becomes easier. After traversing loose, drifting sand with its many undulations for a mile or so, a more solid formation is reacned, which proves to be ancient sandhill strata, erstwhile covered and hardened into rotten sandstone, but now swept bare by the wind, thus proving that the sand drift is not a thing* of yesterday, cut a continuation of an age-long process. The seaward descent begun, the inland view becomes obscured, and the eye may range for miles without glimpsing a single green thng to break the monotony of endless rolling sand dunes and rocky wind-swept ridges. This tract is the southern continuation of a sandy zone strcachmg some 60 miles along the west coast. Proceeding westward, we find the descent suddenly becomes steeper, and the blue of the Tasman Sea comes into view. Descending what was once a high range of sandhills, now consolidated, we find ourselves passing amongst scattered oases of stunted scrub and toi-toi, struggling to keep their tops above the shifting sand. [Some two miles still separate us from the beach, and this stretch is found to consist of a succession of those peculiarshaped dunes with their gradual slope to windward and abrupt clip to leeward ; the intervening hollows sometimes diversified with patches of bleached shells or the dead remains cf submerged forests. Intermittent attempts have been madechiefly by the Government —to check the inland drift of the sand. The general procedure is to endeavour to bind the surface by the estabhsoment cn marram grass, plants being set out in rows a foot or so apart. Here and there one comes upon several acres treated in this way, with varying results. The trouble is "that in the" most exposed situations, where the mischief is proceeding most actively, even the marram fails to establish itself, the constant wind and driving sand being too much for it. In some areas where the marram has become established, and elsewhere, the tree lupin is struggling hard, and often successfully, to "cover the forbidding wastes. Here again the violence and frequency of the wind frustrates nature s more " beneficent intentions. The lupin seeds germinate in thousands on the bare sand, but are buried before they can develop beyond the seedling stage. The problem would appear to he one of creating wind breaks. If this could be done effectively, the rest of the -problem would solve itself, for strange though it may seem, this sand, where once consolidated, is by no means barren, but can support a luxuriant growth of paspalum and other grasses, as well as of many kinds of trees. Amongst the latter is the maritime pine, largely used in reclaiming the sand dunes of southern France : and also the local pinus pinatus. Probably the best procedure would be to sow the seed either in naturally sheltered spot-s or behind artificial breakwinds where the seedlings could not become buried or blown out. As the plants grew they would create further shelter where seedlings would probably establish themselves, for these species of pine seed freely. It is conceivable. that in this wav the who!© area of sand drift, embracing hundreds of square miles, might- he afforested, and become a valuable national asset. Looking further ahead, one can conceive judicious clearings being made of the mature timber and grazing farms being established bv surface sowing. That the sand, which is largely impregnated with Taranaki iron sand, is rich in plant food, is asserted by all the local farmers. During severe gales the fine send is carried for a mile or more over the grass lauds in an impalpable shower, and acts like a ton dressing of manure, the pastures in the vicinity of the sandhills always being in good heart. At one point in this sandy zone a high scrub-covered ridge stretches transverslv across it for about half of its width. On either side of this is 3 steep declivity clothed with tan Med scrub, where the slone is not- precipitous. Tire ridge is interesting for its remains of prehistoric habitation. That it was used as a pass or roadway from and to the coast seems to he indicated by the trouble taken to fortify it with intersecting moats at several points, in such a way that a few defenders could have blocked egress. At what period these were constructed can only be conjectured, but that it cannot have been within a century is shown by the large trees growing in the bottom of the- entrenchments. At one

place the ridge widens out, and here a considerable space appears to have been levelled, though it is now completely overgrown witii large trees. Here and there on this level tract, and at several places in the sides of the aforesaid moat, cave-like excavations have been hollowed out cf the soft sandstone, which consists of the old sand-hill formation before described. The entrance to each cavern is by a small man-hole, beneath which one or more carefully shaped projections of rock have been left to serve as steps. In some instances the entrances and steps are in as good a state of preservation as when they were in use; but in most cases the cavities are caved in or filled with leaf mould. The Maoris of the district seem to have no knowledge or- even tradition of any occupation of this ridge. It is probable that the caverns were used as sepulchres for the bones of the dead, for it- is well known that the Maori custom was to exhume the dead, and after scraping the hones, lay these away in inaccessible places, from which they might afterwards be removed in the event of the tribe migrating. As to the ancient moats, the place may have been used a.s a fortified point of vantage or look-cut station at a date long anterior to its use as a burial ground. It commands an unrivalled view up and down the coast, along which, even in historic times, many a ravaging war party steered its canoes. *