The Monterey Pine (Pinus Radiata) in New Zealand

Abstract

THE MONTEREY PINE (PINUS RADIATA) IN NEW ZEALAND Michael P. McIntyhe San Jose State College In New Zealand the introduction of exotic plants and animals in an attempt to improve the biotic environment has been a continuing process dating back to the Maori in the pro-European era. However, in an isolated and insular environment such as this, there is an ever-attendant risk that the intricate balances of nature may be upset. The rabbit scourge, highly publicized in Australia but also serious in New Zealand, is frequently cited as the classic example of the near disastrous results of introducing a foreign specie into a region where none of its natural enemies exist. Other examples include the European red deer, the Wapiti (Roosevelt elk), the English sparrow, and the starling, all of which have become unwelcome pests, while Scotch gorse has run rampant over large areas, This list of failures is not long by comparison with the many successes which have gradually transformed the biotic landscape of New Zealand into a southern hemisphere approximation of northwest Europe, Among the more recent of the successful exotics has been the Monterey pine (pimis radiata),1 indigenous to the coast of central California. Although systematic propagation of this tree was not begun until after World War I, its growth lias been so rapid that entire forests are now reaching maturity and their exploitation has brought into existence, within the last four years, the largest softwood timber industry in the southern hemisphere, Wood products now rank fourth in export value in New Zealand, exceeded only by the long established wool, meat, and dairy products industries.2 The tree derives its name from its limited occurrence on the Monterey peninsula and adjacent areas of California, In its natural habitat, the Monterey pine has never been seriously considered as having even a remote timber potential, for not only is its range as restricted as any tree in the United States, but it is typically stunted, knotty, and somewhat slow growing as a result of low precipitation, cool temperatures, high winds, thin soils, and heavy fog. There are no really large stands of pinus radiata even on the peninsula; the groves are widely scattered and are found only as far north as Ano Nuevo point and south to San Simeon on the mainland, Actually , this pine is a relict of the pre-ice period, probably originating in the late Tertiary as an insular endemic when the California coast ranges were ? series of disconnected islands paralleling a more easterly coastline. Isolated trees may still be encountered on islands off the coast of southern California and northern Mexico. 1 Pinus insignis is an older designation for the identical specie. - New Zealand, Department of Statistics, New Zealand Official Yearbook, 1958. Wellington, 1958, p. 489. 59 The major pine forests in New Zealand are located on a broad rolling upland in the north central part of the North Island. Fringed by mountains on all sides except the north, this triangular shaped plateau, its apex at Lake Taupo, its base fronting on the Bay of Plenty, has a total area of almost 3000 square miles. Successive lava flows combined with magmatic intrusions have raised it to its present 500- to 1000-foot elevation, and it is characterized by frequent seismic activity and the widespread occurrence of geysers and steam vents, Locally, the entire region is known as the Pumiceland (Fig. 1). Contrary to common American usage, the term pumice in New Zealand is applied indiscriminately to any and all volcanic ash, and the Pumiceland is mantled throughout with varying thicknesses of ash derived from recently active volcanoes along its southern and southwestern margins. As a result, the original climax vegetation was obliterated. When first viewed by Europeans, the region, despite thirty or more inches of well-distributed rainfall each year, a fifty-five to sixty degree temperature average and, by New Zealand standards, a higher than average incidence of sunshine, had a semi-desert appearance with only a widely spaced tussock grass and stunted scrub cover. The forest oriented Maori had shunned this barren upland, but to Europeans the open country appeared to offer emancipation from laborious and costly clearing of forest...