The Vegetation of New Zealand
Horticulture, since it deals with an unlimited number of species, reflects climatic and edaphic conditions to no small degree. Speaking generally, the lowland climate throughout the region, with the exception of the Subantaretic province, permits the cultivation, in the open air, of many species not hardy in Europe, except in the South or in districts possessing a mild insular climate e. g., — Eucalyptus globulus, Acacia melanoxylon, Agave americana, Hakea saligna. Pelargonium zonale. But the greater part of the plants, whether of flower-garden, kitchen-garden or orchard, are those most commonly cultivated in Great Britain and the garden-fashions of that country, so different ecologically, are for the most part slavishly followed. At the same, almost from the foundation of the Colony, there have been enthusiastic amateur gardeners in the different centres and by them, at one time or another, have been introduced an immense and heterogeneous collection of plants hardy in their several localities. Further, there are a number of semi-botanic gardens where considerable collections of trees, shrubs and herbs have been brought together.
In proceeding from north to south, leaving on one side the rank and file of the garden species, a considerable change takes place in the flower gardens more especially, which is most marked on entering the Southern page 375botanical province on its eastern side and thus quite in accordance with the distribution of the indigenous vegetation.
Various species absent in most parts of South Island, and in many other parts of North Island, give a special character to the gardens of Auckland. Amongst such are: — Schinus Molle which attains a great size especially at Thames, Bougainvillea glabra, Datura cofnigera, Euphorbia pulcherrima, the indigenous Meryta Sinclairii, Phytolacca dioica, species of Hibiscus, Tibouchina semidecandra, Ficus macrophylla, Erythrina crista-galli, lemons and oranges. The two latter are grown for commerce, especially near Whangarei. Many species of Eucalyptus, not tolerant of frost, grow excellently in lowland Auckland. Napier possesses a climate much the same as Auckland so far as temperature goes, but drier. Virtually the same subtropical species grow excellently. The horticultural feature of the town is the splendid row of Araucaria excelsa along the esplanade. Taranaki has been named the garden of New Zealand. Here, too, many subtropical plants grow luxuriantly. But the chief horticultural features are the splendid vigour of shrubs of all kinds and the rich abundance of Camellias and Chinese Azaleas. By the time the city of Wellington is reached, the subtropical element has weakened somewhat, still it is plainly to be seen in the presence of Ficus macrophylla, many garden forms of Fuchsia, Lager-stroemia indica, Clethra arborea, species of Bouvardia, Araucaria Bidwillii, Boronia megastigma, many species of Abutilon, Eucalyptus ficifolia and Himalayan rhododendrons in great variety.
Turning now to South Island, various subtropical species can be grown in Nelson and along the coast on the west to as far south as Hokitika and probably much further, but on the east, as soon as the Canterbury Plain is gained, the winter frost forbids the presence of all plants which will not tolerate above— 10° C. Thus the trees and shrubs consist largely of species belonging to Europe, as a whole, California and Japan. Many Tasmanian species, too, are quite hardy. Alpine plants are somewhat difficult to cultivate on account of the north-west wind, and this too forbids the use of tree-ferns which can be grown with success in the open in the wetter parts of North Island. Lowland Banks Peninsula does not answer to the above description, for the climate is much warmer in winter. In Otago, near the coast, the climate of winter is milder than in Canterbury, bat the summers are cooler and there is less sunshine. In consequence, more tender species can be grown in many localities e. g. Leucadendron argenteum. The climate especially favours alpine plants so that not only can European, North American and Himalayan species be grown with the greatest ease, but the indigenous plants, much more difficult to cultivate, thrive amazingly. Further south still, at Invercargill, the great subantarctic herbs grow most vigorously.
Fruit-growing is becoming a thriving industry. Apples, pears, plums and small fruits are grown in many parts of the lowland and montane page 376belts, but commercial orchards are situated for the most part in the following districts, to each of which the area in orchards (including private orchards) is appended: — South Auckland (2800 hectares), East Cape (1070), Sounds-Nelson (2700), North Otago (1800). The best class of gumlands' soil of Auckland is suitable for all classes of fruit, including grapes and citrous fruits. Apple orchards are a special feature of Sounds-Nelson. Central Otago (NO.), with its climate far drier and more sunny than any other part of the region, is particularly suitable for the growing of stone-fruits, notwithstanding its winter cold, greater than elsewhere. But, in order to secure the best results, irrigation is essential.
A most important branch of horticulture or agriculture is forestry. From the earliest days of settlement, first the missionaries, and later the colonists, planted the trees of the homeland, and, with the settlement of South Island, plantations and shelter-belts were established on its treeless plains (the Canterbury Plain more particularly) consisting principally of Eucalyptus globulus (frequently sown in situ), Pinus radiata and Cupressus macrocarpa. But these were far from being the only species planted; indeed all the forest-trees used in Great Britain for economic and ornamental purposes (European, Californian, Japanese &c.) have been introduced, together with many species of Eucalyptus and some of Acacia — the result being that there are now many noble plantations of mixed exotic trees.
Since the subtropical rain-forest regenerates very slowly after its timber trees have been removed, it became necessary as the natural forests were being rapidly destroyed — partly for their timber (wood being almost the sole building material) but far more to make place for grassland — to establish extensive plantations of exotic trees. To begin with, this essential national work was placed in the hands of the Department of Lands and Survey and for a number of years it was ably directed by the late H. T. Matthews whose name must ever stand high as a pioneer of New Zealand commercial forestry; nor must it be forgotten that much of his work was necessarily of an experimental nature.
In 1919 a separate Forestry Department was formed which in 1920 was reorganized as The State Forest Service with Mr. L. M. Ellis as Director of Forestry. Matthews had early on selected a portion of the Volcanic Plateau near Rotorua with its fern heath and low shrubland as the principal scene of his operations, the general climatic conditions from 300 to 600 m. altitude or more, and the easily worked pumice soil being ideal for tree-planting on a large scale, the value of the land also being very low. Various areas, too, in South Island were planted with trees, including part of the tussock-clad Hanmer Plains (NE.). But, under the State Forest Service, planting is being carried out on a far more extensive scale, and the introduction of new methods, and labour-saving devices, have greatly reduced the cost of planting, while also it has been definitely ascertained what page 377species are best fitted for the artificial forests, and trees of inferior value are no longer used. Indeed, the future of New Zealand forestry is full of high promise and in no part of the British Empire does the same class of forestry stand on a higher plane.
Since the inauguration of State afforestation in 1896, nearly 32000 hectares of plantations have been established (N. Z. Official year-Book, 1927:494), and during the season 1926–27 about 8000 hectares was added to this area (Ann. Rep. State Forest Service, 1927:2).
At the present time, the following are the principal species which are being planted: — Pinus radiata (matures in from 30 to 40 years, i. e. 3 crops in 100 years), P. ponderosa, P. laricio and Pseudotsuga taxifolia. But there are many more species in the various plantations, amongst which are Larix decidua (grows splendidly at Hanmer), Sequoia sempervirens (grows rapidly in certain localities), Pinus austriaca, Picea excelsa, and various species of Eucalyptus (many not hardy throughout North and South Island). A rather curious circumstance is the fact that Pinus sylvestris is useless for afforestation in any part of the region; the trees becoming diseased at an early age.