EFFECTS OF FIRE.
Notwithstanding the shortness of the summer season at high altitudes, the subalpine forests in some parts of the park have suffered severely from fire (fig. 1). The bare white trunks of fire-killed silver and alpine firs bear witness to numerous fires which occurred from time to time before the regulations governing the park went into effect. The little resin pockets in the bark of these trees blaze fiercely for a short time and the heat separates the bark from the trunk. In this way the tree is killed, although the naked trunk is left untouched by fire. The destruction of the alpine forest in this way is often erroneously attributed to disease or to the depredation of insects.
There has been little apparent change in the alpine burns within the last 30 years. Reforestation at high altitudes is extremely slow. The seed production is rather scanty and the ground conditions are not favorable for its reproduction. It will take more than one century for nature to replace the beautiful groves which have been destroyed by the carelessness of the first visitors to the mountain.
At low elevations the forest recovers more rapidly from the effects of fire. Between the subalpine areas and the river valleys there are several large ancient burns which are partly reforested. The most extensive of these tracts is the Muddy Fork burn. It is crossed by the Stevens Canyon Trail from Reflection Lakes through the Ohanopecosh Hot Springs. This burn includes an area of 20 square miles in the park and extends north nearly to the glaciers and south for several miles beyond the park boundary nearly to the main Cowlitz River. The open sunlit spaces and wide outlooks afforded by reforested tracts of this character present a strong contrast to the deep shades and dim vistas of the primitive forest. On the whole they have a cheerful and pleasing appearance, very different from the sad, desolate aspect of the alpine burns which less kindly conditions of climate and exposure have kept from reforestation.
The original forest was fire killed many years before the coming of the white man. A few naked and weather beaten stubs are still standing. Only the larger of the fallen trunks remain, and these are rotten except for a few seasoned and weatherworn shells. The second growth is of all ages, from seedlings to trees 12 to 14 inches in diameter. Vine maple, willow, and mountain ash have sprung up along the streams and the hillsides are covered with huckleberry bushes and a variety of grasses and flowering plants.
Similar old burns are found on the ridge between Huckleberry Creek and White River, in the northeastern part of the park, and on the ridge between Tahoma Creek and Kautz Creek below Indian Henrys Hunting Ground.
The old burns in the middle altitudes of the park occupy regions once frequented by the Klickitat Indians. Every summer parties of hunters and berry pickers from the sagebrush plains crossed the Cascades with their horses. They followed the high divides and open summits of the secondary ridges until they came around to the open parks about Mount Rainier where they turned their horses out to graze and made their summer camp. The women picked huckleberries and the men hunted deer and goats. They made great firs to dry their berries and kindled smudges to protect their horses from flies. It was also their custom to systematically set out fires as they returned. Burning made the country better for the Indians. The fires kept down the brush and made it more accessible. Deer could be more easily seen and tracked and the huckleberry patches spread more widely over the hills.
No considerable part of the lower forests of the park has been burned. The principal danger is from lightning. However, few of the trees struck are ignited and these fires are usually extinguished by the rain. On account of the coolness of the air and its greater humidity the fire danger in the forests on the lower slopes of Mount Rainier seems much less than it is in corresponding situations in the main ranges of the Cascades.
AGES AND DIMENSIONS OF TREES.
Trees grow more rapidly at low altitudes than at higher and cooler elevations. Under similar conditions some species increase in size faster than others, but the rate of growth depends principally upon environment. The average increase at the stump in the valley land is about 1 inch in 6 years. A Douglas fir growing along the road between the park boundary and Longmire Springs, at the age of 90 to 120 years may have a breast diameter of 20 inches and yield 700 feet of saw timber. But many of the trees of this size may be much older on account of having grown in the shade or under other adverse conditions. The trees between 200 and 300 years of age are often 40 to 50 inches in diameter and may yield an average of from 2,700 to 5,500 board feet. The largest Douglas firs are sometimes over 600 years old and 60 to 100 inches in diameter. Such trees when sound will produce over 8,000 feet of lumber.
The western red cedar has a shorter and more tapering trunk and its volume in board feet is proportionally smaller. A tree 50 inches in diameter and 175 feet high contains about 3,400 board feet.
The size of the trees decrease rapidly at higher elevations. In the subalpine forest the annual growth is very small. At elevations of 6,000 feet the white-park pine requires 200 years to attain a diameter of 10 to 12 inches. The annual rings are so close together that they can not be distinguished without a magnifying glass.
Last Updated: 02-Feb-2007