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The Lodge-Pole Pine
THE trappers gave the Lodge-Pole Pine (Finns contorta, var. Murrayana) its popular name on account of its general use by Indians of the West for lodge or wigwam poles. It is a tree with an unusually interesting life-story, and is worth knowing for the triumphant struggle which it makes for existence, and also for the commercial importance which, at an early date, it seems destined to have. Perhaps its most interesting and advantageous characteristic is its habit of holding or hoarding its seed-harvests.
Lodge-pole is also variously called Tamarack, Murray, and Two-leaved Pine. Its yellow-green needles are in twos, and are from one to three inches in length. Its cones are about one inch in diameter at the base and from one to two inches long. Its light-gray or cinnamon-gray bark is thin and scaly.
In a typical lodge-pole forest the trees, or poles, stand closely together and all are of the same age and of even size. Seedlings and saplings are not seen in an old forest. This forest covers the mountains for miles, growing in moist, dry, and stony places, claims all slopes, has an altitudinal range of four thousand feet, and almost entirely excludes all other species from its borders.
The hoarding habit of this tree, the service rendered it by forest fires, the lightness of the seeds and the readiness with which they germinate on dry or burned-over areas, its ability to grow in a variety of soils and climates, together with its capacity to thrive in the full glare of the sun, — all these are factors which make this tree interesting, and which enable it, despite the most dangerous forest enemy, fire, to increase and multiply and extend its domains.
During the last fifty years this aggressive, indomitable tree has enormously extended its area, and John Muir is of the opinion that, “as fires are multiplied and the mountains become drier, this wonderful lodge-pole pine bids fair to obtain possession of nearly all the forest ground in the West.” Its geographical range is along the Rocky Mountains from Alaska to New Mexico, and on the Pacific coast forests of it are, in places, found from sea-level to an altitude of eleven thousand feet. On the Rockies it flourishes between the altitudes of seven thousand and ten thousand feet. It is largely represented in the forests of Colorado, Utah, Idaho, and Montana, and it has extensive areas in Oregon and Washington. It is the most numerous tree in Wyoming, occupying in Yellowstone Park a larger area than all other trees combined, while in California it forms the bulk of the alpine forests.
A Typical Lodge-Pole Forest
The lodge-pole readily adapts itself to the most diverse soil and conditions, but it thrives best where there is considerable moisture. The roots accommodate themselves to shallow soil, and thrive in it.
This tree begins to bear fruit at an early age, sometimes when only eight years old, and usually produces large quantities of cones annually. The cones sometimes open and liberate the seeds as soon as they are ripe, but commonly they remain on the tree for years, with their seeds carefully sealed and protected beneath the scales. So far as I have observed, the trees on the driest soil cling longest to their seeds. For an old lodge-pole to have on its limbs twenty crops of un opened cones is not uncommon. Neither is it uncommon to see an extensive lodge-pole forest each tree of which has upon it several hundred, and many of the trees a few thousand, cones, and in each cone a few mature seeds. Most of these seeds will never have a chance to make a start in life except they be liberated by fire. In fact, most lodge-pole seeds are liberated by fire. The reproduction of this pine is so interwoven with the effects of the forest fires that one may safely say that most of the lodge-pole forests and the increasing lodge-pole areas are the result of forest fires.
Every lodge-pole forest is a fire-trap. The thin, scaly, pitchy bark and the live resiny needles on the tree, as well as those on the ground, are very inflammable, and fires probably sweep a lodge-pole forest more frequently than any other in America. When this forest is in a sapling stage, it is very likely to be burned to ashes. If, how ever, the trees are beyond the sapling stage, the fire probably will consume the needles, burn some of the bark away, and leave the tree, together with its numerous seed-filled cones, unconsumed. As a rule, the fire so heats the cones that most of them open and release their seeds a few hours, or a few days, after the fire. If the area burned over is a large one, the fire loosens the clasp of the cone-scales and millions of lodge-pole seeds, are released to be sown by the great eternal seed-sower, the wind. These seeds are thickly scattered, and as they germinate readily in the mineral soil, enormous numbers of them sprout and begin to struggle for existence. I once counted 84,322 young trees on an acre.
The trees often stand as thick as wheat in a field and exclude all other species. Their growth is slow and mostly upright. They early become delicate miniature poles, and often, at the age of twenty-five or thirty years, good fishing-poles. In their crowded condition, the competition is deadly. Hundreds annually perish, but this tree clings tenaciously to life, and starving it to death is not easy. In the summer of 1895 I counted 24,271 thirty-year-old lodge-poles upon an acre. Ten years later, 19,040 of these were alive. It is possible that eighty thousand, or even one hundred thousand, seedlings started upon this acre. Sometimes more than half a century is required for the making of good poles.
On the Grand River in Colorado I once measured a number of poles that averaged two inches in diameter at the ground and one and one half inches fifteen feet above it. These poles averaged forty feet high and were sixty-seven years of age. Others of my notes read: “9728 trees upon an acre. They were one hundred and three years of age, two to six inches in diameter, four and a half feet from the ground, and from thirty to sixty feet high, at an altitude of 8700 feet. Soil and moisture conditions were excellent. On another acre there were 4126 trees one hundred and fifty-four years old, together with eleven young Engelmann spruces and one Pinus flexilis and eight Douglas firs. The accumulation of duff, mostly needles, averaged eight inches deep, and, with the exception of one bunch of kinnikinick, there was neither grass nor weed, and only tiny, thinly scattered sun-gold reached the brown matted floor.”
After self-thinning has gone on for a hundred years or so, the ranks have been so thinned that there are openings sufficiently large to allow other species a chance to come in. By this time, too, there is sufficient humus on the floor to allow the seeds of many other species to germinate. Lodge-pole thus colonizes barren places, holds them for a time, and so changes them that the very species dispossessed by fire may regain the lost territory. Roughly, the lodge-pole will hold the ground exclusively from seventy-five to one hundred and fifty years, then the invading trees will come triumphantly in and, during the next century and a half, will so increase and multiply that they will almost exclude the lodge-pole. Thus Engelmann spruce and Douglas fir are now growing where lodge-pole flourished, but let fire destroy this forest and lodge-pole will again claim the territory, hold it against all comers for a century or two, and then slowly give way to or be displaced by the spruces and firs.
The interesting characteristic of holding its cones and hoarding seeds often results in the cones being overgrown and embedded in the trunk or the limbs of the trees. As the cones hug closely the trunk or the limbs, it is not un common for the saw, when laying open a log at the mill, to reveal a number of cones embedded there. I have in my cabin a sixteen-foot plank that is two inches in diameter and six inches wide, which came out of a lodge-pole tree. Embedded in this are more than a score of cones. Probably most of these cones were of the first crop which the tree produced, for they clung along the trunk of the tree and grew there when it was about an inch and a quarter in diameter. The section upon which these cones grew was between fifteen and twenty-five feet from the ground.
The seeds of most conifers need vegetable mould, litter, or vegetation cover of some kind in which to germinate, and then shade for a time in which to grow. These requirements so needed by other conifer seeds and seedlings are detrimental to the lodge-pole. If its seeds fall on areas lightly covered with low huckleberry vines, but few of them will germinate. A lodge-pole seed that germinates in the shade is doomed. It must have sunlight or die. In the ashes of a forest fire, in the full glare of the sun, the seeds of the lodge-pole germinate, grow, and flourish.
Wind is the chief agency which enables the seeds to migrate. The seeds are light, and I know of one instance where an isolated tree on a plateau managed to scatter its seeds by the aid of the wind over a circular area fifty acres in extent, though a few acres is all that is reached by the average tree. Sometimes the wind scatters the seeds unevenly. If most of the seeds are released in one day, and the wind this day prevails from the same quarter, the seeds will take but one course from the tree; while changing winds may scatter them quite evenly all around the tree.
A camping party built a fire against a lone lodge-pole. The tree was killed and suffered a loss of its needles from the fire. Four years later, a long green pennant, tattered at the end and formed of lodge-pole seedlings, showed on the mountain-side. This pennant began at the tree and streamed out more than seven hundred feet. Its width varied from ten to fifty feet.
The action of a fire in a lodge-pole forest is varied. If the forest be an old one, even with much rubbish on the ground the heat is not so intense as in a young growth. Where trees are scattered the flames crawl from tree to tree, the needles of which ignite like flash-powder and make beautiful rose-purple flames. At night fires of this kind furnish rare fireworks. Each tree makes a fountain of flame, after which, for a moment, every needle shines like incandescent silver, while exquisite light columns of ashen green smoke float above. The hottest fire I ever experienced was made by the burning of a thirty-eight-year lodge-pole for est. In this forest the poles stood more than thirty feet high, and were about fifteen thousand to an acre. They stood among masses of fallen trees, the remains of a spruce forest that had been killed by the same fire which had given this lodge-pole forest a chance to spring up. Several thousand acres were burned, arid for a brief time the fire traveled swiftly. I saw it roll blazing over one mountain-side at a speed of more than sixty miles an hour. It was intensely hot, and in a surprisingly short time the flames had burned every log, stump, and tree to ashes. Several hundred acres were swept absolutely bare of trees, living and dead, and the roots too were burned far into the ground.
Several beetles prey upon the lodge-pole, and in some localities the porcupine feeds off its inner bark. It is also made use of by man. The wood is light, not strong, with a straight, rather coarse grain. It is of a light yellow to nearly white, or pinkish white, soft, and easily worked. In the West it is extensively used for lumber, fencing, fuel, and log houses, and millions of lodge-pole railroad-ties are annually put to use.
Most lodge-poles grow in crowded ranks, and slow growth is the result, but it is naturally a comparatively rapid grower. In good, moist soil, uncrowded, it rapidly builds upward and outward. I have more than a score of records that show that it has made a quarter of an inch diameter growth annually, together with an upright growth of more than twelve inches, and also several notes which show where trees standing in favorable conditions have made half an inch diameter growth annually. This fact of its rapid growth, together with other valuable characteristics and qualities of the tree, may lead it to be selected by the government for the reforestation of millions of acres of denuded areas in the West. In many places on the Rockies it would, if given a chance, make commercial timber in from thirty to sixty years.
I examined a lodge-pole in the Medicine Bow Mountains that was scarred by fire. It was two hundred and fourteen years of age. It took one hundred and seventy-eight years for it to make five inches of diameter growth. In the one hundred and seventy-eighth ring of annual growth there was a fire-scar, and during the next thirty-six years it put on five more inches of growth. It is probable, therefore, that the fire destroyed the neighboring trees, which had dwarfed and starved it and thus held it in check. I know of scores of cases where lodge-poles grew much more rapidly, though badly fire-scarred, after fires had removed their hampering competitors.
There are millions of acres of young lodge-pole forests in the West. They are almost as impenetrable as canebrakes. It would greatly increase the rate of growth if these trees were thinned, but it is probable that this will not be done for many years. Meantime, if these forests be protected from fire, they will be excellent water-conservers. When the snows or the rains fall into the lodge-pole thickets, they are beyond the reach of the extra dry winds. If they are protected, the water-supply of the West will be protected; and if they are destroyed, the winds will evaporate most of the precipitation that falls upon their areas.
I do not know of any tree that better adjusts itself to circumstances, or that struggles more bravely or successfully. I am hopeful that before many years the school-children of America will be well acquainted with the Lodge-Pole Pine, and I feel that its interesting ways, its struggles, and its importance will, before long, be appreciated and win a larger place in our literature and also in our hearts.