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

GIANT SEQUOIA (SEQUOIA WASHINGTONIANA).

This tree is the crowning achievement of the vegetable kingdom in size and majesty and age. It is one of the only two survivors of a once numerous genus, which, before the glacial period, was spread across the American Continent and, indeed, across Europe as well. The other now living sequoia is the redwood (Sequoia sempervirens) of the California coast which nearly divides honors with the big tree itself as the largest conifer, if not the largest tree, in the world. The redwood is as tall, or even taller than the big tree, both attaining heights beyond 300 feet; but while the big tree attains a diameter of nearly 30 feet (above the root swelling), the redwood is always more slender.

In foliage the big tree is a scale-leaved tree; but in the seedling stage the leaves are entirely free from the twig and are needle like in form, while in youthful trees, though increasingly scale-like, they still have long, free tips. In youth the branches of the big tree are slender, and the basal ones are long, giving to the tree it broadly pyramidal form. The big tree is still young when other trees of the forest around it are mature or even approaching old age. So it is not until 200 or 300 years of age that the lower branches are thinned out. As maturity approaches, at perhaps 1,000 years of age, the remaining branches, now grown to enormous size, stand out in gnarled and picturesque strength and are clothed with dense masses of blue-green foliage. The bark of the tree, at first smooth and purplish to leaden gray, soon becomes broken into ridges, and on the great trunks of the giant veterans the smooth surface film has long since been flaked off, exposing the cinnamon red color beneath. On such trunks the bark is from 1 to 2 feet thick and is separated into long, heavily-rounded parallel ridges which makes the great stems look like the titanic fluted columns of some giant temple.

The size of the big tree has been often exaggerated. The extreme height actually measured is about 330 feet. That they may reach 350 feet is not unlikely, for the largest trees have almost without exception been broken off at the top by lightning. But statements of 400 feet or over are unquestionably beyond the truth. The extreme diameter above the enormous root swellings is about 27 feet. Obviously this is the only significant way to measure the diameter, for the root swelling is no part of the cylindrical shaft. But such measurements can be made only with difficulty, and measurement at more convenient points have been made at no standard height for the big tree. That the measurements at the base are not really significant is apparent from a comparison of the figures which have been given for the General Grant and General Sherman trees.

FIG. 6.—Mariposa Grove of big trees.

The big tree grows very rapidly in youth, but not sufficient study has been given to its growth to make reliable averages available. Under favorable conditions it may grow to be a foot in diameter at 40 years old, and it is then about 60 feet high. Such a rate of growth has been known to continue for 250 years. Indeed John Muir reports one tree which was 9 feet in diameter and 243 feet high at an age of 259 years. Such growth is doubtless much more rapid than the average, and the big tree, like all other trees, as maturity comes, slows down its rate of growth. In one tree reported by Prof. William R. Dudley the increase in diameter for several centuries was only from 4 to 6 inches per century. But this maturity with the big tree does not ordinarily come under at least 1,000 years. At any rate, it is fairly certain that most, even of the great veterans of the big-tree forest, are much younger than is popularly supposed, and are probably from 1,500 to 2,500 years old. The strongest influence upon the growth of the tree is that exercised by the quality of the location in which it grows. Two trees have been found very near each other, one 24 feet in diameter, the other 25 feet, while the age of the first was 1,300 years and that of the second was 2,300 years. The oldest tree of whose age record there is no question was slightly over 3,000 years. The exact age of a tree can be determined in no other way than by counting the rings of wood which the tree lays on, one for each year of growth. The two trees which have just been cited will serve to show how impossible is even an approximately correct determination of the age of one standing tree by the use of averages or by comparison with the age of another single tree. It is not denied that the sequoia may grow to greater age than 3,000 years. John Muir counted the age of one giant stump in the Kings River Forest in which the rings for many hundred years were so fine as to require 50 or even 100 of them to make a single inch of radial growth, and the rings were much disturbed in places by fire and other injury; but he states that he counted at least 4,000 years of growth. It would therefore be rash to say that the big tree can not attain an age of even 5,000 years. On the other hand, the largest trees are certainly the strongest survivors among many that have perished around them, and these exceptionally sturdy trees grew, in all probability, with more than average rapidity. Estimates of 8,000 years for the age of these trees, based on averages or upon the growth of smaller felled trees, are valueless and almost certainly beyond the truth.

But even an age of 4,000 years must fill him who reflects upon it with awe. The ancestors of other trees which are found with the sequoia in the forest undoubtedly lived at the beginning of that period as now. But of only the sequoia were the very trees upon which we look to-day living in that far-off dawn. When Cheops dreamed the first pyramid some of these hoary giants of to-day doubtless already were springing up and hopefully taking possession of this very soil above which in lordly height and grandeur they look down upon us of four millenniums after; while Abraham and Moses and David established and led the people of Israel these hopeful seedlings grew through an exuberant youth; in the lusty strength of approaching prime they were entering into their kingdom over the forest when imperial Rome began; they stood in a calm and undaunted maturity when Jesus trod the Judean hills; and when William of Normandy fought on the field of Hastings they were already putting on the hoary garments of age. Yet there they still stand to-day, after another millennium has sped, in calm serenity and majesty, unhurt by disease, unscarred by all save fire and the hand of man, while we, creatures of a day, creep about and peep beneath their mighty shade and pass away, while they live on. And there is no visible reason, barring foolhardy destruction by man, why they should not still live for another millennium or more.

The big tree grows preferably in cool, moist situations, in dense forest on gentle slopes, and in basins and draws where soil moisture is plentiful. Its best development, which occurs in the sugar-pine type, is at elevations of from 6,000 to 7,000 feet, where the annual precipitation is from 40 to 60 inches. Its ability to withstand less favorable conditions is much greater than was formerly supposed, and it can grow, especially at the south, on drier ridges and slopes within its normal altitude, as well as downward into the altitude of the yellow-pine type and upward to 8,000 feet elevation into the fir.

The big tree is a frequent seeder and the most prolific one of any Sierra tree. Especially heavy seed years occur at intervals of from four to five seasons. The trees may begin to bear seed in the open as early as their twentieth year, although in dense forest the beginning is delayed until about the one hundred and fiftieth year. The cones are oval and from 2 to 3 inches long, and each cone may contain from 100 to 200 seeds, while so bountifully does the tree produce that a single full-grown specimen may bear 1,000,000 cones a year.

It was formerly believed that the big tree was a vanishing race of trees. This belief was partly due to the fact that in the Calaveras Grove, which was first discovered, and in the other northern groves there is little or no reproduction. This lack, however, is due to the more unfavorable climatic and other conditions which affect germination; in the southern part of this range seedlings and young saplings cover a favorable spot wherever an opening in the forest gives access to the sunlight and where mineral soil is near to the surface. As many as 2,500 seedlings have been counted on it square rod of ground. An excellent example of this young reproduction can be seen at Atwell's mill, on the Mineral King Road, in the Sequoia National Park. No one can see these lusty crowds of young trees, in every stage of growth, and believe that the species is in any immediate danger of extinction.

The big tree is singularly healthy and free from disease. It lives so long that lightning is sure some day to strike its lofty head, and the repeated fires of centuries may scar and disfigure its base, even though its bark is enormously thick and its wood difficult to ignite and burn. But of the diseases which take off its neighbors, the fir and the pine, it knows almost nothing, and its power of recuperation from injuries, such as fire, is greater than that of any other species of the Sierra Forest. To these facts is doubtless due the marvelous approach to immortality which is enjoyed by this wonderful tree.

The widely isolated groves in which the big tree occurs in the north, where it was first discovered, offered another reason for supposing it to be a dying race, of which such a distribution is usually a sign. But it is now known that the great canyons which form the breaks between these groves were the paths of mighty glaciers which formerly flowed down the Sierra Ranges. The sequoia now grows on the highlands where the ice first disappeared. The southern part of the range was less heavily glaciated than the northern, and this is believed to be responsible for the wider and more continuous distribution of the sequoia at present in that region. Exactly what the past history of the big tree has been must still be left to scientific discovery. But there is no reason, except perhaps at the extreme north, to suppose that in its present home it is facing decline or extinction.

The wood of the big tree when freshly cut is of a beautiful rose-red color, turning gradually darker upon exposure to the air. In the living tree the wood is never found decayed at the heart, and even after felling it may lie on the ground for centuries with no loss except of the sapwood. To its extreme durability is due the fact its most extensive use in the past has been for fence posts and grapevine stakes. The radial grain of the wood is very beautiful and would make it a handsome cabinet wood, except for the disadvantage of its extreme softness. The wood of this species, which is now made into lumber, is sold as redwood, along with the true redwood of the coast, although it is somewhat softer and more brittle than the latter. It is estimated that the largest sequoias may contain as much as a half million feet of lumber in a single tree. But every lover of this magnificent tree must hope that such use of it may not much longer continue.