NATIONAL PARK SERVICE Forests of Yosemite, Sequoia, and General Grant National Parks

LODGEPOLE PINE (PINUS CONTORTA).

This tree (fig. 15) has a very wide distribution, and in large areas of the Rocky Mountains is an important tree. It is a small tree, from 20 to 30 inches in diameter and 60 to 100 feet tall in the Sierra region. Its leaves are about 2 inches long and wide and flat in comparison with the needles of most pines. They are distinguished from most of the other Sierra pines by their occurrence in bundles of two. The bark of the tree is thin and light colored, scaling up in small thin flakes. In the Sierras the tree grows mostly in moist soil around high mountain streams and meadows, the latter of which it is the first tree to capture as they slowly dry out. In the Rocky Mountains this tree occupies much more arid situations than it does in the Sierras.

FIG. 15.—Lodgepole pine (Pinus contorta) 5 feet in diameter, 120 feet high.

The lodgepole pine is a very prolific seeder, and in the high mountain meadows its reproduction is often so thick that a way can be forced through it with difficulty. This pine is exceedingly intolerant of shade. For this reason it forms a temporary type. In the Sierra Mountain meadows it is crowded out by the dense shade of the firs as soon as it has built up the ground to sufficient dryness to permit the firs to come in. A peculiarity which interestingly affects the distribution of this tree is the extreme slowness with which its small oval cones open and discharge their seed. They often stay closed for many years until the tree is killed and the cones opened by the heat of a forest fire. A dense, even-aged stand of lodgepole seedlings then springs up, ahead of all other invaders, and takes entire possession of the ground until in due course of time they are crowded out by some more slowly entering tree which can shade them out. In the Rocky Mountains vast areas are thus covered by the lodgepole pine. In the Sierras this peculiarity of the cones is much less marked, but the lodgepole doubtless owes a large portion of the area which it covers in the northern part of Yosemite Park to the aid of fire.

The growth of the lodgepole pine is rapid at first, as it is in all trees which can endure little shading. The rate of growth falls off much earlier than it does in any of the trees which have been discussed. In the Sierra region an average 12-inch tree is about 50 feet tall, a 24-inch tree is 75 feet tall, and a 36-inch tree about 90 feet tall. In favorable places in the meadows it sometimes reaches a height of 130 feet. The largest tree which has been reported in the middle Sierra region is 57 inches in diameter.

Lodgepole pine is extensively sawed for lumber in the northern Rocky Mountains, but in the Sierras better woods are so abundant and so much more accessible that the little lodgepole offers no inducements to the lumberman. The straight, slender form of the tree, however, fits it excellently for use as telephone poles, and a considerable use is developing in this direction.