Wild Life on the Rockies

by Enos A. Mills

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 uncommon 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 forest. 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, and 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.