A look at some trees other than pines

Press, 11 July 1980, Page 17

A look at some trees other than pines

This is the first in a series of articles which will appear during the winter months—tree-planting time. It has been written by DERRICK ROONEY. Future articles will describe some of the lesscommon pines, other coniferous trees, including the Leyland cypresses which are rapidly gaining popularity, and non-coniferous trees. There will also be an article on how to assess the value of the timber in a w r oodlot or shelter belt.

/ ‘‘The radiata pine,” a ‘farm forester said to me .recently, “is a wonderful •tree. You can hack it plant it in the poorest soil and On the most site, and it comes tip smiling.” - Indeed, the people who

grow -pines come up smilJng, too, because Pinus a tree which in -the wild, occurs only in a ■; restricted area of the •-Monterey Peninsula. Cali- > fornia, is the basis of Canterbury’s milling in- ? dustry.

4 Pinus radiata is the > most widely planted forest tree in New Zealand; its K acreage vastly exceeds ’■ that of any other exotic '• species. And there are

..■. probably more pines planted in shelter belts and ? farm woodlots than any v other tree — more, even, than the übiquitous macr- ’ ocarpas and Arizona cypresses. ? But if Pinus radiata is [' an economic triumph, it i, can .be argued that aes- ; thetically it is a disaster. * One of the complaints t, most frequently voiced by > travellers through the countryside is t, of the gloomy and sombre aspect of the serried ranks ? of pines that break the £ plains. ’ Need this be so? i, Undoubtedly, pines and - Arizona cypresses will £ continue to be planted in L vast numbers, because i these trees, dowdy though i they may be, are best 7 adapted to cope with the : demanding climate of cen;'tral Canterbury. But in the sheltered

areas, and in the better soils, when shelter .belts are. , required, there is scope for more imaginative planting. Near Methven, for example, several farms have highly attractive road frontages as a result of the judicious planting of ornamental European trees; and I know one farm on the central plains where ex-

tensive use has been made of Photinia robusta, a small, evergreen tree with attractive, rusty-red young growths. But the majority of shelter plantings are restricted to a handful of species. The purpose of these articles is to describe a few alternative trees that might be used, not to replace the pines and “Arizonicas,” perhaps, but to supplement them, and add a little aesthetic uplift to the countryside. Some of them might be found in other branches of the pine family, for example among’ the spruces and firs of the Northern Hemisphere. Firs and spruces are very closely related, to each other and to pines. Thev are not unlike each other in appearance, and are often confused.

They are widely . distributed in the temperate regions of the Northern Hemisphere, and there are many species of both kinds in Europe, North Africa, Asia, the Himalayas, and North America. At high latitudes they occur down to sea level, but at lower latitudes they reach considerable alti-

tudes. Thus ’they are coolclimate trees. Firs are placed in the genus abies, spruces in picea. Species of abies carry their cones upright, on the upper branches; when ripe, the cones disintegrate. Picea cones are pendulous, and do not disintegrate.

Winter buds are one of the identification points of conifers. In the firs these may be resinous or nonresinous, more often the former; the winter buds of spruces are not resinous. On the branchlets of picea species, woody, peg-like leaf bases persist after the leaves have fallen; these are probably the major point of identification. Although these trees belong to a vast, and widely distributed family, the number of species likely to grow well in Canterbury is limited. Many come from areas of high rainfall; some grow in almost rain-forest cona ditions. Some of the Asiatic species are adapted to a monsoon climate. Others are adapted to life in a cold climate, with a very

short summer growing season and a long period of dormancy In winter, when temperatures maybe below freezing for months. But there are species well able to cope with a dry, Canterburytype climate, and others that might be expected to

do well in the wetter soils around the foothills.

All the species to be discussed in this article may not thrive in Canterbury conditions; they are simply some that this writer has seen growing, and has admired. Other species not discussed may well be of equal, or superior, merit,

Among ■ the first in line is Ables alba, the common fir. This is a large tree, reaching 50m, with a girth up to 6m, from the mountains of central and southern Europe, where it often occurs in large stands from which other species are excluded. The timber from forestgrown trees is light, soft, and straight-grained. It splits well, works easily,

and though not durable can be treated, just as pine can. It requires a cool climate, with clearly defined seasons, and is tender to spring frosts, s it would not be expected to thrive on the plains. It may grow in the wetter areas of the foothills, where it would find the deep soils that it needs. This species will succeed in clay soils.

The Spanish fir. Abies pinsapo, is already widely recognised as a shelter tree of high quality in Canterbury. It withstands considerable wind and drought, and succeeds in a variety of soil types. It is well clad down to ground level and makes a shelter belt that is dense but not impermeable- Despite its origins in Europe’s sunny south, it is very hardy, having been cultivated as far north as Norway. The ultimate height is about 30m, and the likely growth rate about 30cm a year. Few firs are more ornamental. Abies concolour, the Colorado fir is another drought-resistant species. It occurs in the Rocky Mountains, from Colorado south to Mexico. The Colorado fir is one of the few species in its genus that are shade tolerant. and it can be used to underplant other species. But ultimately it will grow very large, up to 50m. It is less subject to crippling, insect attacks than Abies alba, to which it is closely related. The wood milled from Northern Hemisphere trees is of good quality, light, strong, easily worked and odourless.

One of the most adaptable species is the Nikko fir. Abies homolepis, which is native to Japan and, like many Japanese conifers, is very ornamental. It occurs, in an altitude range from 800 to 1650 m, and is very hardy. Though its natural preference is for deep, rich soils, it will suceed in dry conditions, and will also tolerate air pollution.

The best-known fir is Abies procera, formerly known as A. magnifica. This is the ‘‘noble fir” that grows in dense stands in the coastal ranges of Washington and Oregon and the Siskiyou Mountains of California. David Douglas, the fir man, in-

troduced it to cultivation about 1830.

Abies procera is a montane species, and grows best in high valleys; there is a fine specimen at Lake Coleridge. In areas where soil and climate are suited to its growth it is the most beautiful of the firs, and one of the most handsome of all coniferous trees.

Christmas tree of the Northern Hemisphere — is Picea abies, which grows in large forest stands throughout most of Europe. Fossil evidence indicates that it occurred in Britain, too, before the last ice-age. Thus the Norway spruce is not only a large and very handsome tree, but one tolerant of a wide range of growing conditions. Wood from forest-grown trees is said to be of high quality, resilient, easily worked, and finishing well. But unpruned trees, produce poor logs, spoilt by knots. The Norway spruce is widely planted in the United Kingdom, where it accounts for 8 per cent of all forestry plantings. Its growth rate there is such that it is expected to top 25m in 50 years; a height of 22m after 30 years has been recorded in Wales.

The limiting factor oft the widespread use of this fine tree is its intolerance of summer drought, and consequently it is well know in this country mainly in the form of a handful 1 of dwarf varieties, cultivated in gardens.

Brewer ’.s weeping spruce, Picea breweriana, has been planted on some Canterbury properties.

This tree occurs wild only in a few isolated

localities in the Siskiyou Mountains of California and Oregon, where it was discovered in 1863 by Professor Brewer, a Yale University scientist.

Brewer’s spruce is a hardy species, and a beautiful one, tolerant of drought and possibly wind resistant, but is handicapped by slow growth. Twenty-year-old trees may be no more than 6m high, thus it is not an economic proposition for forestry. However, I have seen it used in a two-tier planting with pine; when the pines mature, and are felled, the spruce will be big enough to break the wind on its own. But at present it is a fairly uncommon tree, though it is apparently not difficult to propagate. Picea omorika, the Servian spruce, is another which is occasionally planted in Canterbury as an ornamental. This tree, which grows wild only in a small area on the banks of the Drina River in Yugoslavia, between 900 m and 1700 m above sea level, is very distinctive. The crown is steeple shaped, and the trunk is very tall and slender — a tree 3.5 m high may have a girth no bigger than Im. The Servian spruce succeed better than any other species of picea in hot, dry soils, but the best growth rates are recorded in soft maritime climates. It is apparently not fussy about soils, though in the wild it grows on limestone. Little information is available about its wind hardiness.

. Picea sitchensis, the Sitka spruce, is the tree that won the First World War for the Royal Air

Force. Its timber, light, durable, and very strong, built the British fighter aircraft of the Great War. and vast quantities were imported to Britain from North America between 1914 and 1918.

The Sitka spruce is a large tree, topping 70m when mature, with a girth of 12m. Its distribution extends from northern California to Alaska, always within 80km of the coast, and other than in size it varies little throughout its range. Die ‘‘type locality” is Puget Sound, Washington, where it was found in 1792.

The Sitka spruce was introduced to cultivation by Douglas about 1830. Its timber is regarded as the best of the spruce woods, and in North America is available in large sizes, in planks up to 10m long and 80cm wide. Growth of the Sitka spruce in mild climates is ver j’ rapid, sometimes 1.5 m a year. It is tolerant of drought, and in the wild is found growing in dryish, sandy coastal soils as well as on boggy land. But it is a tree that must be nursed for its first few years, because it is intolerant of competition when young. In Scotland, plantings have been suppressed by heather. Though it favours a mild, maritime climate, the Sitka sprucb is vert 1 ' adaptable, and has succeeded even in cold bogland on exposed sites in the rigorous climate of Scotland. It is the most important exotic tree in the United .Kingdom, occupying some 17 per cent of the area planted in conifers.