FIRE ALARM

New Zealand Listener, Volume 9, Issue 231, 26 November 1943, Page 4

FIRE ALARM

(Written for "The Listener" by

J.O.H

TRIPP

HE writer of this article is careful to point out that he has no standing as a man of science. He writes as a hill-country farmer, after consultation with other hill-country men,

ITLER is merely a passing blot on the earth’s crust. Erosion is an_ insidious, creeping thing, #hat starts disintegrating the earth’s crust often before it is recognised. How many of us realise that it is the top six inches of soil on this world that keeps us alive-that in fact, if it were removed, every living thing above water would perish, except, perhaps, the sea birds, ice animals and Eskimos? And how many of us realise that almost every desert was caused by man’s folly, even the Sahara? It used to be the granary of Italy 1800 years ago. The Romans overcropped it, and erosion got a start. With no decayed vegetable matter to hold it together, the soil rapidly disintegrated with the help of the wind and the rain, until only sand was left, which gradually seeped over field after field until the damage was beyond repair. In Africa the Highlands of Nyasaland have been so eroded that the Assistant | Director of Agriculture reported in 1934 that they were supporting no more than half the population they were capable of carrying a century before. To those who have eyes to see, surely the same sort of thing is: happening to the high country of New Zealand. In the United States the area of formerly cultivated land, now rendered useless by erosion, is no less than 109 million acres. And erosion in the shape of dust storms caused 50,000 farms in one area alone to be deserted. In many of the desert borderlards in Australia the drifting sand has covered countless acres of farm land, and miles and miles of good netting fences. In some places the fences are buried four deep, each new fence having been built on top of the sand-covered oneextreme cases, no doubt, but an indication of what can happen. "The Creeping, Dangerous Type" However, it is New Zealand’s high country erosion problem that I propose to discuss in this article. For many of us the word erosion conjures up pictures of ugly gashes torn out of hillsides by water. Perhaps this is because such erosion is easily noticed, photographed end brought before the public eye. Many a property-owner imagines that he has no erosion because he has none of these water-torn gullies, when in reality sheet erosion may be taking steady toll of his top soil, all unnoticed. These are the commonest types of erosion: (1) Sheet Erosion-It is the creeping, dangerous type, and is hard for the average man to detect, It is a

ey i i hi hi hi ih hh i i i i i i i ii combination of water and wind that slowly removes all the top fertile earth without forming visible gullies. (2) Gully Erosion-Most of us know something about this, because it cannot be mistaken for anything other than water-torn gullies~ (3) Wind Erosion-This type belongs to the drier districts, where dust and sand storms can cover up acres of good land, or blow away the top soil of good ploughed land. It is caused by river-bed erosion, wrong _ burning methods, rabbits, etc; and by certain dry-farming methods beyond the scope of this article. Effect on Electric Power The main object of this article is to interest the town and country dweller (as well as high country men), in,a most important aspect of erosion that has had less notice than it deservesnamely, erosion from the uncontrolled burning of hill country. Hill country erosion, in certain areas, does, in fact, directly affect townspeople, by cutting down hydro-electric power, and will have a greater and greater adverse effect as the years go by, if the evil is not checked now. These bad effects are brought about in two ways. Firstly, the "run off" from the catchment areas not being impeded by the vegetable matter (which has been burnt), causes rivers to rise and fall rapidly, an unfavourable situation for power production, in which a gradual rise and fall is the ideal. Secondly, the unimpeded, fast-flowing water, rushing down the _hill-sides, carries with it stones, debris, and silt in ever-increasing volume. All this settles in the artificial lakes that serve the electric turbines. This steadily reduces the supply of storage water in the lakes, the top layers of which- are so very necessary in regulating "peak" loads. One dam in Marlborough, for example, has already been completely silted up. Another striking example of gradual silting can be seen in the Waitaki lake, which serves the largest power scheme in the South Island. This artificial lake is about five miles long, and already the top mile of it is considerably silted up, the deposits being plainly visible at low water, when part of the silt is actually above water,

I am personally convinced that some of this quick silting is due to high rents in the first instance, causing many sheep stations to be overstocked, and to be burnt far too much, in the mistaken idea that more feed was thus produced, Palatable tussock is so produced for the first season, but after that the tussocks become smaller. and smaller until little is left either to burn or feed on. Rabbits, of course, bring this about far more quickly. However, politics is not my topic here. Some History The first hill burning appears to have been done by Tripp and Acland in March, 1856. These men pioneered the grazing of sheep on hill country, which at that time ran only wild pigs. To quote from: R. M. Burdon’s High Country: On the eastern slopes of the Southern Alps the vegetation was much more varied than it is to-day, flax, toi toi and snow tussocks of immense size covered the slopes. Cabbage trees also grew in great profusion before they were thinned out by fire. .... Tripp and Acland decided to burn extensively in the hope that finer grasses might grow out of the ashes of the ranker plants. The fires ‘were so huge that, according to Tripp, the finest print could be read a mile off by the light of them. These and similar fires were the primary cause of much of the present hillcountry erosion. No blame is, of course, attachable to these early pioneers, as New Zealand hill knowledge was nonexistent in 1856. Indeed, this particular fire took place at quite the wrong time of year (March), and probably with no regard *to the moisture content of ground or tussock. Since these early days, large areas of tussock haye been burnt every August and September, each area being burnt about once in every four or five years, depending on the seasons, stocking, etc. Suggested Remedies Several of the following points have been discussed with other sheep men, and I am indebted to them. for their help. Many a fire has been lit on bone-dry tussock with the idea that it was safe, that a sou’-wester was developing, or that it was just coming ‘on to (continued on next page)

INDISCRIMINATE BURNING BY FARMERS |

(continued from previous page) rain, the idea being that the rain would quickly make the tussocks grow again and put the fire out before it spread too far. This reasoning is, of course, entirely wrong, because no amount of rain can completely restore a hill-facing tussock that has been burnt in the dry state, since the tussock base and the ground in between have been burnt. Nothing can justify burning’ when the tussock base is dry.. Many hill men burn during the correct months, but Without any regard to soil and tussock dampness, a vital point to which little or no consideration has been paid in years gone by. During my 22 years’ experience in both wet and dry climates, ranging from 50 inches to 17 inches of rain per year, I suppose I have made as many mistakes as most men over burning, and from these sorry experiences have now come to the conclusion (after various ‘experiments), that there are certain definite rules that should be followed when burning. But first of all, let us consider the pros and cons of burning from the sheep man’s point of view:

FOR BURNING 1. Protection Against Accidental Fires Accidental fires may occur during a drought, destroying many _tussocks beyond recovery, and the grasses between them. There might also be a large loss of sheep. Fire breaks’ should, therefore, be burnt where considered necessary. 2. Improvement. of Unpaletable Tussock.Burning does achieve this, but at a cost. In addition to the erosion risks, if there are any rabbits in the vicinity, they will flock on to the "burn" and eat the tussocks right out. Overstocking will do almost as much damage. If tussock base and ground surface are not

really damp when burnt, the resulting damage far outweighs any temporary feed obtained. From this latter paragraph should be formed the one great law that every hill-man should have in mind when considering controlled burning. The burning law should read something like this: "During the months of August and September only may burning be done, but never later than two days after rain if the sun has been shining during that period. If overcast conditions are continuous, it would be safe to burn up to a week after rain. "In cases of doubt, some tussocks should be felt, the bottom third of which should be very damp and the ground between also damp. It there is a nor’-wester the day after rain, burning must not be done later than that one day. A ‘rain day’ for burning purposes should be one in which not less than 20 points of rain have fallen." I should think this rule could be applied from Marlborough to South Otago with rainfalls of up to 35 inches per annum; for wetter areas the rule could be modified a little.

3. To Facilitate Mustering in Snow-grass--This reason is not good enough. Snowgrass should never be burnt for any reason other than that of fire risk, and even then as sparingly as possible. Snowgrass is not found on sunny facings below about 2500 feet, and, of course, the rainfall down to this level is very much heavier in proportion to the rainfall at lower levels, therefore, the leaching of the soil above this level is very much greater than below. Imagine the sorry state of a beautiful snowgrass, covering an area of perhaps 20 or more square feet, suddenly shrivelled by fire to a small black hummock surrounded by barren yellowish earth. A_ golden opportunity for erosion to start its work. Unlike ordinary tussock, snowgrass is edible without being burnt. Besides, if sheep are feeding at the higher levels when caught by snow, they can’t exist on burnt-out snowgrass. Even in deep snow sheep can live for three or four weeks without undue weakening if snow catches them on a good thick area of snowgrass. Experience has also taught me the fallacy of lawyer-bush burning. The young shoots that grow after burning will catch hoggets more easily than the "old man" variety, which usually has a large amount of dead wood below, with the young shoots well above the sheep’s heads. AGAINST BURNING This is the case against burning: 1. Decayed and decaying vegetable matter is destroyed. 2. Native grasses between tussocks are destroyed and weeds take their place. 3. Vast amounts of nitrogen are destroyed. 4. Erosion starts before vegetable matter can again be built up. 5. The country is unable to resist drought. 6. Burnt snowgrass increases snow risk, The above points require no further explanation. "There Should Be Laws" _ Hill men should treat burning-off as the most important operation of the year, of even greater importance than shearing and lambing. Indeed, the subject is of such importance that not only must we re-adjust our minds to this matter, but laws should be drafted to regulate the few who never listen to reason. Anyone lighting a tussock fire out of season should be heavily fined. Everyone should consider it his duty to inform the local stock inspectors of such fires. Nor should fires ever be lighted except by the owner or manager. It should also be urged that every, run-holder has a rain gauge, so that he will know exactly when to burn. The divergence of opinions as to the amount of rain that has fallen, especially overnight, is amazing. It does not take long for a hill-man to judge how much rain he should add to his rain gauge reading for the country on which he intends to burn. For instance, on this place (Hakataramea), a reading of 20 points at the house means about 26 points on the hills 500 feet above, and two miles away. At 1000 feet it would be proportionately heavier, about 34 points. We hope to be able to print a second article by Mr. Tripp dealing with some sugare Py os of this high-country probem. oe