Читать книгу American Forest Trees - Henry H. Gibson - Страница 23
LODGEPOLE PINE
(Pinus Contorta)
ОглавлениеThe common name of this tree was given it because its tall, slender, very light poles were used by Indians of the region in the construction of their lodges. They selected poles fifteen feet long and two inches in diameter, set them in a circle, bent the tops together, tied them, and covered the frame with skins or bark. The poles were peeled in early summer, when the Indians set out upon their summer hunt, and were left to season until fall, when they were carried to the winter’s camping place, probably fifty miles distant. Tamarack is a common name for this pine in much of its range; it is likewise known as black pine, spruce pine, and prickly pine. Its leaves are from one to two inches long, in clusters of two. The small cones adhere to the branches many years—sometimes as long as twenty—without releasing the seeds, which are sealed within the cone by accumulated resin. The vitality of the seeds is remarkable. They don’t lose their power of germination during their long imprisonment.
The lodgepole pine has been called a fire tree, and the name is not inappropriate. It profits by severe burning, as some other trees of the United States do, such as paper birch and bird cherry. The sealed cones are opened by fire, which softens the resin, and the seeds are liberated after the fire has passed, and wing their flight wherever the wind carries them. The passing fire may be severe enough to kill the parent tree without destroying or bringing down the cones. The seeds soon fall on the bared mineral soil, where they germinate by thousands. More than one hundred thousand small seedling trees may occupy a single acre. Most of them are ultimately crowded to death, but a thick stand results. Most lodgepole pine forests occupy old burns. The tree is one of the slowest of growers. It never reaches large size—possibly three feet is the limit. It is very tall and slender. A hundred years will scarcely produce a sawlog of the smallest size.
The range of this tree covers a million square miles from Alaska to New Mexico, and to the Pacific coast. Its characters vary in different parts of its range. A scrub form was once thought to be a different species, and was called shore pine.
The wood is of about the same weight as eastern white pine. It is light in color, rather weak, and brittle, annual rings very narrow, summerwood small in amount, resin passages few and small; medullary rays numerous, broad, and prominent. The wood is characterized by numerous small knots. It is not durable in contact with the ground, but it readily receives preservative treatment. In height it ranges from fifty to one hundred feet.
The government’s estimate of the stand of lodgepole pine in the United States in 1909 placed it at 90,000,000,000 feet. That makes it seventh in quantity among the timber trees of this country, those above it being Douglas fir, the southern yellow pines (considered as one), western yellow pine, redwood, western hemlock, and the red cedar of Washington, Oregon, and Idaho.
Lodgepole pine has been long and widely used as a ranch timber in the Far West, serving for poles and rails in fences, for sheds, barns, corrals, pens, and small bridges. Where it could be had at all, it was generally plentiful. Stock ranges high among the mountains frequently depend almost solely upon lodgepole pine for necessary timber.
Mine operators find it a valuable resource. As props it is cheap, substantial, and convenient in many parts of Colorado, New Mexico, Wyoming, and Montana. A large proportion of this timber which is cut for mining purposes has been standing dead from fire injury many years, and is thoroughly seasoned and very light. It is in excellent condition for receiving preservative treatment.
Sawmills do not list lodgepole pine separately in reports of lumber cut, and it is impossible to determine what the annual supply from the species is. It is well known that the quantity made into lumber in Colorado, Wyoming, Montana, and Idaho is large. Its chief market is among the newly established agricultural communities in those states. They use it for fruit and vegetable shipping boxes, fencing plank, pickets, and plastering lath.
Railroads buy half a million lodgepole pine crossties yearly. When creosoted, they resist decay many years. Lodgepole pine has been a tie material since the first railroads entered the region, and while by no means the best, it promises to fill a much more important place in the future than in the past. It is an ideal fence post material as far as size and form are concerned, and with preservative treatment it is bound to attain a high place. It is claimed that treated posts will last twenty years, and that puts them on a par with the cedars.
In Colorado and Wyoming much lodgepole was formerly burned for charcoal to supply the furnaces which smelted ore and the blacksmith shops of the region. This is done now less than formerly, since railroad building has made coal and coke accessible.
In one respect, lodgepole pine is to the western mountains what loblolly pine is to the flat country of the south Atlantic and other southern states. It is aggressive, and takes possession of vacant ground. Although the wood is not as valuable as loblolly, it is useful, and has an important place to fill in the western country’s development. Its greatest drawback is its exceedingly slow growth. A hundred years is a long time to wait for trees of pole size. Two crops of loblolly sawlogs can be harvested in that time. However, the land on which the lodgepole grows is fit only for timber, and the acreage is so vast that there is enough to grow supplies, even with the wait of a century or two for harvest. The stand has increased enormously within historic time, the same as loblolly, and for a similar reason. Men cleared land in the East, and loblolly took possession; fires destroyed western forests of other species and lodgepole seized and held the burned tracts.
If fires cease among the western mountains, as will probably be the case under more efficient methods of patrol, and with stricter enforcement of laws against starting fires, the spread of lodgepole pine will come to a standstill, and existing forests will grow old without much extension of their borders.
Jeffrey Pine (Pinus jeffreyi) is often classed as western yellow pine, both in the forest and at the mill. Its range extends from southern Oregon to Lower California, a distance of 1,000 miles, and its width east and west varies from twenty to one hundred and fifty miles. It is a mountain tree and generally occupies elevations above the western yellow pine. In the North its range reaches 3,600 feet above sea level; in the extreme South it is 10,000 feet. The darker and more deeply-furrowed bark of the Jeffrey pine is the usual character by which lumbermen distinguish it from the western yellow pine. It is known under several names, most of them relating to the tree’s appearance, such as black pine, redbark pine, blackbark pine, sapwood pine, and bull pine. It reaches the same size as the western yellow pine, though the average is a little smaller. The leaves are from four to nine inches long, and fall in eight or nine years. The cones are large, and armed with slender, curved spines. The seeds are too heavy to fly far, their wing area being small. It is a vigorous tree, and in some regions it forms good forests. Some botanists have considered the Jeffrey pine a variety of the western yellow pine.
Gray Pine (Pinus sabiniana), called also Digger pine because the Digger Indians formerly collected the seeds, which are as large as peanuts, to help eke out a living, is confined to California, and grows in a belt on the foothills surrounding the San Joaquin and Sacramento valleys. Its cones are large and armed with hooked spines. When green, the largest cones weigh three or four pounds. Leaves are from eight to twelve inches long, in clusters of two and three, and fall the third and fourth years. The wood is remarkable for the quickness of its decay in damp situations. It lasts one or two years as fence posts. A mature gray pine is from fifty to seventy feet high, and eighteen to thirty inches in diameter. Some trees are much larger. It is of considerable importance, but is not in the same class as western yellow and sugar pine. The wood is light, soft, rather strong, brittle. The annual rings are generally wide, indicating rapid growth. Very old gray pines are not known. An age of 185 years seems to be the highest on record. The wood is resinous, and it has helped in a small way to supply the Pacific coast markets with high-grade turpentine, distilled from roots. It yields resin when boxed like the southern longleaf pine. There are two flowing seasons. One is very early, and closes when the weather becomes hot; the other is in full current by the middle of August. It maintains life among the California foothills during the long rainless seasons, on ground so dry that semi-desert chaparral sometimes succumbs; but it is able to make the most of favorable conditions, and it grows rapidly under the slightest encouragement. The seedlings are more numerous now than formerly, which is attributed to decrease of forest fires. The tree has enemies which generally attack it in youth. Two fungi, Peridermium harknessi, and Dædalia vorax, destroy the young tree’s leader or topmost shoot, causing the development of a short trunk. The latter fungus is the same or is closely related to that which tunnels the trunk of incense cedar and produces pecky cypress.
Gray pine has been cut to some extent for lumber, but its principal uses have been as fuel and mine timbers. Many quartz mines have been located in the region where the tree grows; and the engines which pumped the shafts and raised and crushed the ore were often heated with this pine. Thousands of acres of hillsides in the vicinity of mines were stripped of it, and it went to the engine house ricks in wagons, on sleds, and on the backs of burros. In two respects it is an economical fuel for remote mines: it is light in weight, and gives more heat than an equal quantity of the oak that is associated with it.
Chihuahua Pine (Pinus chihuahuana) is not abundant, but it exists in small commercial quantities in southwestern New Mexico and southern Arizona. Trees are from fifty to eighty feet high, and from fifteen to twenty inches in diameter. The wood is medium light, soft, rather strong, brittle, narrow ringed and compact. The resin passages are few, large, and conspicuous; color, clear light orange, the thick sapwood lighter. The tree reaches best development at altitudes of from 5,000 to 7,000 feet. When the wood is used, it serves the same purposes as western yellow pine; but the small size of the tree makes lumber of large size impossible. The leaves are in clusters of three, and fall the fourth year. The cones have long stalks and are from one and a half to two inches long.