100 YEARS OF CHANGE New Zealand’s Vegetation

Korero (AEWS), Volume 3, Issue 4, 26 March 1945, Page 8

100 YEARS OF CHANGE New Zealand’s Vegetation

Condensed from “A Century’s Change: Natural to Cultural Vegetation in New Zealand,” by Kenneth B. Cumberland.

The change from natural to cultural vegetation has taken twenty centuries in Europe and four in America. New Zealand has done the job in a hundred years, but this rapid changeover has only been achieved at the cost of irreparable damage to our agricultural resources. The basic causes of the injuries caused by thoughtless exploitation of the land are sketched in the following article. f This country before the Maori arrived in the fourteenth century was probably clothed entirely in forest. About 97,200

square miles of it. Until that time, no man or beast (save the moa) had been present to cause destruction. But by 1840 and the arrival of the pakeha, the area had dwindled to 53,000 miles, as a result, it is thought, of such natural agents as showers of volcanic ash and lava flows in the North Island and bush fires in the South. Other types of vegetation were bracken fern, tussock, and the high-altitude plants. In 1840 all the districts with heavy rainfall were bush-clad, the vegetation varying so much that some parts could be

called subtropical, others subantarctic. Tussock occurred in the low-rainfall areas of Otago, Canterbury, and Marlborough, and on the porous pumice soils of the interior of the North Island. The bush was a dense rain-forest (except in the South, where the beech was dominant), and included a mass of tall timber trees, a tangle of medium-sized trees, looped lianas, massive parasites, and tree ferns, and a host of low ground plants. North Auckland had its typical taraire and kauri; but the main North Island forest was composed of the pine family—rimu, totara, matai, miro, and kahikatea—together with the tawa, kamahi, and rata.

In. the South, these tall timber trees were largely replaced by the frostresisting oeech, though the subtropical and subantarctic zones dovetailed to a large extent. Beech were found in the Rimutaxa, Tararuas, and Ruahines, and pines occurred as far south as Stewart Island. In general, however, the beech was confined to the steep alpine slopes, too dry and too high to support other vegetation. Even the beech gave way to the tussock in the lee of the Alps and over the plains of Central Otago, the Mackenzie country, and the Canterbury Plains. The line of contact between the tussock and forest was sharply defined, but never regular owing to the ups and downs of the country.

The earliest Europeans found more than half the South Island, or almost 25,000 square miles, a yellow-brown sea of tussock, extending from the east coast to the foothills up to about 4,000 ft. Low rain fall, wide temperature ranges, and dry winds encouraged it. The various kinds of tussock grasses had company in the tumatakuru, spear-grass, and gaunt cabbage-trees, while herbs, sedges, and grass sheltered in its shadow. This band of hardy plants reduced the effects of the wind, held the soil, and preserved the moisture in it. The land suffered no deterioration.

The Maoris, besides being few in numbers, employed a conservative agriculture. They had few cultivable crops, and the chief of these, the kumara, would grow well only in the North Island. They cleared patches of fern land and perhaps bush, and planted the kumara and taro,

but their main food-supply came from the edible fruits and berries of the forest, from birds, and from the fish in the rivers, lakes, and sea. The forest of Tane was sacred and was preserved by a tapu stronger than our own laws.

Europeans, before 1840, destroyed all they touched. The seals were killed off, the cachalot whales decimated, kauris and kahikateas were exported as spars. The missionaries introduced the European system of cultivation. But no real disturbance of the land took place till the Wakefield plan of settlement took effect, with the foundation of Wellington, New Plymouth, Nelson, and Wanganui, together with the settlements in Otago and Canterbury. In 1853, inauguration of cheap land deals caused large-scale expansion of European influence, and with it the destruction of the native vegetation The land was sacrificed to the get-rich-quick greed of the squatter, the gold-miner, the sawmiller, and the “bonanza wheat ” farmer. The South Island, carrying the least bush cover, was easier to exploit and so was the first to profit from the stimulus proffered by Australia at this time.

1851, gold in Australia. From all corners of the world men came to make their fortunes. But you can’t cat gold. So other men became rich by selling food and clothing to the gold-diggers—wheat for bread, sheep for meat and wool. Runholders in the South Island waxed fat on the “ golden fleece ” and on the bonanza wheat.

Land—land—more land. Gradually the runs bit deeper till they licked at the feet of the Alps. But the tussock wasn’t enough for even the hardy Merinos. “ Burn the tussock—increase the flocks so that they will eat the tussock. The tussock is useless.” But those bold pioneers didn’t reflect that by shaving the tussock they bared the soil to the wind, and the soil reacts as a face would. It chaps—but flakes of skin become shingle slips and land slides ; erosion licks his chops.

Until 1875 the South Island tussock plains were given over to sheep, but after that date the population increase due to the gold rushes and a new export trade to Australia rocketed the demand for

cash crops. Wheat became the mainstay of the small plains farmer —the tussock was ploughed in and crops were harvested year after year. As a result, soil fertility was drained away, yields declined, and the soil damage resulted. This is at the foot of many present-day problems. Gojd did much for New Zealand. It conjured up population and capital. But it also left a trail of wanton destruction. Wherever the miners went with pick, sluice, and dredge, they left scars on the tortured earth, scars which breed slips and gullies to this day.

Sheep and gold weren’t the only offenders. The “ bush burn ” farmer at least replaced the forest with grass. But the sawmiller left the land mutilated and dead. So, too, the gum-digger in the North Auckland district laid waste thousands of acres of the best timberproducing territory in New Zealand, and is largely responsible for the slow development of this district to-day.

The “ bush burn ” farmer in this period from 1875-90 devastated a far greater area than that touched by miller and digger—and with more ruinous effect. The process is still used in the remote backblocks : the large trees are felled, a “burn" reduces the whole area to' a blackened wilderness, seed is then sown — grasses, clover, and perhaps mustard, rape, and turnips—and, the first green flame alight, sheep are turned in to tread down the seed-bed and chew out the bracken and second growth. Most of New Zealand’s famous grass-lands have been brought into being by this brutal method. In 1882 the first ship, weighted down with frozen mutton and lamb, arrived in

the Thames estuary. By 1895 refrigeration had come to stay, and this practice opened a new field for agriculture. The small dairy-farmer took his place alongside the squatter, and for the first time the North Island exceeded the South in population. The new development affected the natural vegetation cover in various ways. Bush-burning and ferncrushing were extended, 14,000 square miles of forest being put to the fire, sometimes in places where soil stability seems impossible if the soil is not held together by forest. Swamp areas were drained and became some of the most

productive land in the country— e-g-, the Hauraki - Piako lowland and the Manawatu-Horowhenua area. In the South Island a mixed arable economy flourished, with farms of moderate size, and shelter-belts and wind-breaks making a patchwork of the plains. In conjunction with this more intensive farming has come the practice of artificial fertilizing, which is doing much to restore the soil fertility lost in the old days. To-day thirty-two million sheep and almost five million cattle browse where once was forest. From these, directly or indirectly, all New-Zealanders make their living.

In spite of the intensive development of the last hundred years, there are still three pioneer fringes against which the forces of civilization are steadily moving. In North Auckland the gum country is being reclaimed and grassed, though the struggle against the stiff clay soils is an uphill one. In the central North Island plateau, afforestation, tourist traffic — ~e-g-, Rotorua —and its development as a dairying area have done much to increase its population. In Westland a bitter struggle is being carried on against dense pine forest and the water-logged, sour soils. Timber-milling and beef-cattle raising are gradually opening up the country as far south as Jackson’s Bay. Having surveyed the natural vegetation, it now remains to look at the replacements man has made, and also to observe the way Nature is revolting

against the change. The vegetation covering the greatest area is grass-land, native and exotic ; 17,000,000 acres are in artificially sown pasture and 14,000,000 acres in tussock. Together these make up almost half the total area of the Dominion. These grass-lands embrace several types. The first class, the high-producing pastures for which New Zealand is famous, is comparatively limited. Usually they are reclaimed swamps and are consequently well watered, with mild winters. They are ideal for small dairy holdings aiming at butter, cheese, and domestic-milk production. Usually such farms are divided into small fields of rye-grass and white

clover, which are kept fertile by intensive grazing and the lavish use of artificial fertilizers. Such areas are the Manawatu and the Waikato district.

Good - quality pastures are more numerous. They occur in parts of North Auckland, in the coastal belt from New Plymouth to Otaki. In each area of this kind the grass differs due to cultural and soil factors, but cocksfoot is very common. Farming, too, is varied, with sheep as numerous as cattle. Fattening ewes and lambs is also important. Most of the North Island and much of the South Island pastures fall into the third class, described as “ surfacesown.” A typical area is that from Palliser Bay to East Cape, which has been reclaimed from forest and scrub for sheep - station country. These pastures are produced either by disturbance of the original vegetation— e.g., by fire —or by sowing. In time the sown types usually revert to a mixture of native and exotic grasses. This pasture is used for both sheep and cattle, and the holdings range from 1,500 acres to 8,000 acres.

In most cases this last type of pasture shows a gradual return to its original state. Erosion is common, and the original inhabitants, fern and scrub, creep back to such an extent that the annual rate of deterioration is almost 100,000 acres. In all, there are 4,500,000 acres of fern, scrub, and second growth, in which the deterioration is so great as to be a national problem. A few years ago this land was covered in forest: now it is a scene of desolation, slip scarred and scrub covered, with its population, both human and animal, being withdrawn. Parts of Hawke’s Bay and the highcountry tussock of the South Island

are examples of this terrain, although the South Island, being originally tussock, has not suffered the same transformation as the northern areas. Overstocking, burning, and rabbits, however, have so depleted the tussock that erosion is rife.

Even to-day roughly 16 per cent, of the total area of New Zealand is under forest, two-thirds of which is in State control. Five hundred mills yearly cut out 30,000 acres, but the time is approaching when this wasteful “ single crop ” economy will be replaced by better methods. Unfortunately, much of the exotic forest is insignis pine situated in remote localities. It is of poor quality and mostly of one age class.

In the last twenty-five years several factors have been at work to change the agricultural position— e.g., the largescale export of apples, the trade in chilled beef, the export of pig meat, and the use of irrigation. It is safe to say that the area under pasture is now at a maximum, and the changes which will follow this war will probably be towards a decline from this point. It is by no means certain that we shall be able to rely to the same extent on our exports of butter, wool, frozen meat and, cheese as before. The threat of margarine and synthetic fibre is too real to be ignored. Thus, a diverse agriculture is indicated, practised in a declining area. At the same time, the abandonment of hill country useless as pasture would make possible an afforestation plan which would heal the soil scars of the North Island and possibly would help to prevent any further expansion of the South Island’s rocky wastes. New Zealand must conserve her soil fertility and exploit to the full the natural advantages which are hers.