The Yosemite/Chapter 7
[Editor’s Note: The “Big Tree” is now known as the giant sequoia, Sequoiadendron giganteum (see page 122 of The Jepson Manual: Higher Plants of California, James C. Hickman, editor, University of California Press, 1993)]
Between the heavy pine and silver fir zones towers the Big Tree (Sequoia gigantea ), the king of all the conifers in the world, “the noblest of the noble race.” The groves nearest Yosemite Valley are about twenty miles to the westward and southward and are called the Tuolumne, Merced and Mariposa groves. It extends, a widely interrupted belt, from a very small grove on the middle fork of the American River to the head of Deer Creek, a distance of about 260 miles, its northern limit being near the thirty-ninth parallel, the southern a little below the thirty-sixth. The elevation of the belt above the sea varies from about 5000 to 8000 feet. From the American River to Kings River the species occurs only in small isolated groups so sparsely distributed along the belt that three of the gaps in it are from forty to sixty miles wide. But from Kings River south-ward the sequoia is not restricted to mere groves but extends across the wide rugged basins of the Kaweah and Tule Rivers in noble forests, a distance of nearly seventy miles, the continuity of this part of the belt being broken only by the main cañons. The Fresno, the largest of the northern groves, has an area of three or four square miles, a short distance to the southward of the famous Mariposa grove. Along the south rim of the cañon of the south fork of Kings River there is a majestic sequoia forest about six miles long by two wide. This is the northernmost group that may fairly be called a forest. Descending the divide between the Kings and Kaweah Rivers you come to the grand forests that form the main continuous portion of the belt. Southward the giants become more and more irrepressibly exuberant, heaving their massive crowns into the sky from every ridge and slope, waving onward in graceful compliance with the complicated topography of the region. The finest of the Kaweah section of the belt is on the broad ridge between Marble Creek and the middle fork, and is called the Giant Forest. It extends from the granite headlands, overlooking the hot San Joaquin plains, to within a few miles of the cool glacial fountains of the summit peaks. The extreme upper limit of the belt is reached between the middle and south forks of the Kaweah at a height of 8400 feet, but the finest block of big tree forests in the entire belt is on the north fork of Tule River, and is included in the Sequoia National Park.
In the northern groves there are comparatively few young trees or saplings. But here for every old storm-beaten giant there are many in their prime and for each of these a crowd of hopeful young trees and saplings, growing vigorously on moraines, rocky edges, along water courses and meadows. But though the area occupied by the big tree increases so greatly from north to south, here is no marked increase in the size of the trees. The height of 275 feet or thereabouts and a diameter of about twenty feet, four feet from the ground is, perhaps, about the average size of what may be called full-grown trees, where they are favorably located. The specimens twenty-five feet in diameter are not very rare and a few are nearly three hundred feet high. In the Calaveras grove there are four trees over 300 feet in height, the tallest of which as measured by the Geological Survey is 325 feet. The very largest that I have yet met in the course of my explorations is a majestic old fire-scarred monument in the Kings River forest. It is thirty-five feet and eight inches in diameter inside the bark, four feet above the ground. It is burned half through, and I spent a day in clearing away the charred surface with a sharp ax and counting the annual wood- rings with the aid of a pocket lens. I succeeded in laying bare a section all the way from the outside to the heart and counted a little over four thousand rings, showing that this tree was in its prime about twenty-seven feet in diameter at the beginning of the Christian era. No other tree in the world, as far as I know, has looked down on so many centuries as the sequoia or opens so many impressive and suggestive views into history. Under the most favorable conditions these giants probably live 5000 years or more though few of even the larger trees are half as old. The age of one that was felled in Calaveras grove, for the sake of having its stump for a dancing-floor, was about 1300 years, and its diameter measured across the stump twenty-four feet inside the bark. Another that was felled in the Kings River forest was about the same size but nearly a thousand years older (2200 years), though not a very old-looking tree.
So harmonious and finely balanced are even the mightiest of these monarchs in all their proportions that there is never anything overgrown or monstrous about them. Seeing them for the first time you are more impressed with their beauty than their size, their grandeur being in great part invisible; but sooner or later it becomes manifest to the loving eye, stealing slowly on the senses like the grandeur of Niagara or of the Yosemite Domes. When you approach them and walk around them you begin to wonder at their colossal size and try to measure them. They bulge considerably at the base, but not more than is required for beauty and safety and the only reason that this bulging seems in some cases excessive is that only a comparatively small section is seen in near views. One that I measured in the Kings River forest was twenty-five feet in diameter at the ground and ten feet in diameter 220 feet above the ground showing the fineness of the taper of the trunk as a whole. No description can give anything like an adequate idea of their singular majesty, much less of their beauty. Except the sugar pine, most of their neighbors with pointed tops seem ever trying to go higher, while the big tree, soaring above them all, seems satisfied. Its grand domed head seems to be poised about as lightly as a cloud, giving no impression of seeking to rise higher. Only when it is young does it show like other conifers a heavenward yearning, sharply aspiring with a long quick- growing top. Indeed, the whole tree for the first century or two, or until it is a hundred or one hundred and fifty feet high, is arrowhead in form, and, compared with the solemn rigidity of age, seems as sensitive to the wind as a squirrel’s tail. As it grows older, the lower branches are gradually dropped and the upper ones thinned out until comparatively few are left. These, however, are developed to a great size, divide again and again and terminate in bossy, rounded masses of leafy branch-lets, while the head becomes dome-shaped, and is the first to feel the touch of the rosy beams of the morning, the last to bid the sun good night. Perfect specimens, unhurt by running fires or lightning, are singularly regular and symmetrical in general form though not in the least conventionalized, for they show extraordinary variety in the unity and harmony of their general outline. The immensely strong, stately shafts are free of limbs for one hundred end fifty feet or so The large limbs reach out with equal boldness a every direction, showing no weather side, and no other tree has foliage so densely massed, so finely molded in outline and so perfectly subordinate to an ideal type. A particularly knotty, angular, ungovernable-looking branch, from five to seven or eight feet in diameter and perhaps a thousand years old, may occasionally be seen pushing out from the trunk as if determined to break across the bounds of the regular curve, but like all the others it dissolves in bosses of branchlets and sprays as soon as the general outline is approached. Except in picturesque old age, after being struck by lightning or broken by thousands of snow-storms, the regularity of forms is one of their most distinguishing characteristics. Another is the simple beauty of the trunk and its great thickness as compared with its height and the width of the branches, which makes them look more like finely modeled and sculptured architectural columns than the stems of trees, while the great limbs look like rafters, supporting the magnificent dome- head. But though so consummately beautiful, the big tree always seems unfamiliar, with peculiar physiognomy, awfully solemn and earnest; yet with all its strangeness it impresses us as being more at home than any of its neighbors, holding the best right to the ground as the oldest strongest inhabitant. One soon becomes acquainted with new species of pine and fir and spruce as with friendly people, shaking their outstretched branches like shaking hands and fondling their little ones, while the venerable aboriginal sequoia, ancient of other days, keeps you at a distance, looking as strange in aspect and behavior among its neighbor trees as would the mastodon among the homely bears and deers. Only the Sierra juniper is at all like it, standing rigid and unconquerable on glacier pavements for thousands of years, grim and silent, with an air of antiquity about as pronounced as that of the sequoia.
The bark of the largest trees is from one to two feet thick, rich cinnamon brown, purplish on young trees, forming magnificent masses of color with the underbrush. Toward the end of winter the trees are in bloom, while the snow is still eight or ten feet deep. The female flowers are about three-eighths of an inch long, pale green, and grow in countless thousands on the ends of sprays. The male are still more abundant, pale yellow, a fourth of an inch long and when the pollen is ripe they color the whole tree and dust the sir and the ground. The cones are bright grass-green in color, about two and a half inches long, one and a half wide, made up of thirty or forty strong, closely-packed, rhomboidal scales, with four to eight seeds at the base of each. The seeds are wonderfully small end light, being only from an eighth to a fourth of an inch long and wide, including a filmy surrounding wing, which causes them to glint and waver in falling and enables the wind to carry them considerable distances. Unless harvested by the squirrels, the cones discharge their seed and remain on the tree for many years. In fruitful seasons the trees are fairly laden. On two small branches one and a half and two inches in diameter I counted 480 cones. No other California conifer produces nearly so many seeds, except, perhaps, the other sequoia, the Redwood of the Coast Mountains. Millions are ripened annually by a single tree, and in a fruitful year the product of one of the northern groves would be enough to plant all the mountain ranges in the world.
As soon as any accident happens to the crown, such as being smashed off by lightning, the branches beneath the wound, no matter how situated, seem to be excited, like a colony of bees that have lost their queen, and become anxious to repair the damage. Limbs that have grown outward for centuries at right angles to the trunk begin to turn upward to assist in making a new crown, each speedily assuming the special form of true summits. Even in the case of mere stumps, burned half through, some mere ornamental tuft will try to go aloft and do its best as a leader in forming a new head. Groups of two or three are often found standing close together, the seeds from which they sprang having probably grown on ground cleared for their reception by the fall of a large tree of a former generation. They are called “loving couples,” “three graces,” etc. When these trees are young they are seen to stand twenty or thirty feet apart, by the time they are full-grown their trunks will touch and crowd against each other and in some cases even appear as one.
It is generally believed that the sequoia was once far more widely distributed over the Sierra; but after long and careful study I have come to the conclusion that it never was, at least since the close of the glacial period, because a diligent search along the margins of the groves, and in the gaps between fails to reveal a single trace of its previous existence beyond its present bounds. Notwithstanding, I feel confident that if every sequoia in the Range were to die today, numerous monuments of their existence would remain, of so imperishable a nature as to be available for the student more than ten thousand years hence.
In the first place, no species of coniferous tree in the Range keeps its members so well together as the sequoia; a mile is, perhaps, the greatest distance of any straggler from the main body, and all of those stragglers that have come under my observation are young, instead of old monumental trees, relics of a more extended growth.
Again, the great trunks of the sequoia last for centuries after they fall. I have a specimen block of sequoia wood, cut from a fallen tree, which is hardly distinguishable from a similar section cut from a living tree, although the one cut from the fallen trunk has certainly lain on the damp forest floor more than 380 years, probably thrice as long. The time-measure in the case is simply this: When the ponderous trunk to which the old vestige belonged fell, it sunk itself into the ground, thus making a long, straight ditch, and in the middle of this ditch a silver fir four feet in diameter and 380 years old was growing, as I determined by cutting it half through and counting the rings, thus demonstrating that the remnant of the trunk that made the ditch has lain on the ground more than 380 years. For it is evident that, to find the whole time, we must add to the 380 years the time that the vanished portion of the trunk lay in the ditch before being burned out of the way, plus the time that passed before the seed from which the monumental fir sprang fell into the prepared soil and took root. Now, because sequoia trunks are never wholly consumed in one forest fire, and those fires recur only at considerable intervals, and because sequoia ditches after being cleared are often left unplanted for centuries, it becomes evident that the trunk-remnant in question may probably have lain a thousand years or more. And this instance is by no means a late one.
Again, admitting that upon those areas supposed to have been once covered with sequoia forests, every tree may have fallen, and every trunk may have been burned or buried, leaving not a remnant, many of the ditches made by the fall of the ponderous trunks, and the bowls made by their upturning roots, would remain patent for thousands of years after the last vestige of the trunks that made them had vanished. Much of this ditch-writing would no doubt be quickly effaced by the flood-action of overflowing streams and rain-washing; but no inconsiderable portion would remain enduringly engraved on ridge-tops beyond such destructive action; for, where all the conditions are favorable, it is almost imperishable. Now these historic ditches and root-bowls occur in all the present sequoia groves and forests, but, as far as I have observed, not the faintest vestige of one presents itself outside of them.
We therefore conclude that the area covered by sequoia has not been diminished during the last eight or ten thousand years, and probably not at all in post-glacial time. Nevertheless, the questions may be asked: Is the species verging toward extinction? What are its relations to climate, soil, and associated trees?
All the phenomena bearing on these questions also throw light, as we shall endeavor to show, upon the peculiar distribution of the species, and sustain the conclusion already arrived at as to the question of former extension. In the northern groups, as we have seen, there are few young trees or saplings growing up around the old ones to perpetuate the race, and inasmuch as those aged sequoias, so nearly childless, are the only ones commonly known the species, to most observers, seems doomed to speedy extinction, as being nothing more than an expiring remnant, vanquished in the so-called struggle for life by pines and firs that have driven it into its last strongholds in moist glens where the climate is supposed to be exceptionally favorable. But the story told by the majestic continuous forests of the south creates a very different impression. No tree in the forest is more enduringly established in concordance with both climate and soil. It grows heartily everywhere — on moraines, rocky ledges, along watercourses, and in the deep, moist alluvium of meadows with, as we have seen, a multitude of seedlings and saplings crowding up around the aged, abundantly able to maintain the forest in prime vigor. So that if all the trees of any section of the main sequoia forest were ranged together according to age, a very promising curve would be presented, all the way up from last year’s seedlings to giants, and with the young and middle-aged portion of the curve many times longer than the old portion. Even as far north as the Fresno, I counted 536 saplings and seedlings, growing promisingly upon a landslip not exceeding two acres in area. This soil-bed was about seven years old, and had been seeded almost simultaneously by pines, firs, libocedrus, and sequoia, presenting a simple and instructive illustration of the struggle for life among the rival species; and it was interesting to note that the conditions thus far affecting them have enabled the young sequoias to gain a marked advantage. Toward the south where the sequoia becomes most exuberant and numerous, the rival trees become less so; and where they mix with sequoias they grow up beneath them like slender grasses among stalks of Indian corn. Upon a bed of sandy floodsoil I counted ninety-four sequoias, from one to twelve feet high, on a patch of ground once occupied by four large sugar pines which lay crumbling beneath them — an instance of conditions which have enabled sequoias to crowd out the pines. I also noted eighty-six vigorous saplings upon a piece of fresh ground prepared for their reception by fire. Thus fire, the great destroyer of the sequoia, also furnishes the bare ground required for its growth from the seed. Fresh ground is, however, furnished in sufficient quantities for the renewal of the forests without the aid of fire — by the fall of old trees. The soil is thus upturned and mellowed, and many trees are planted for every one that falls.
It is constantly asserted in a vague way that the Sierra was vastly wetter than now, and that the increasing drought will of itself extinguish the sequoia, leaving its ground to other trees supposed capable of flourishing in a drier climate. But that the sequoia can and does grow on as dry ground as any of its present rivals is manifest in a thousand places. “Why, then,” it will be asked, “are sequoias always found only in well-watered places?” Simply because a growth of sequoias creates those streams. The thirsty mountaineer knows well that in every sequoia grove he will find running water, but it is a mistake to suppose that the water is the cause of the grove being there; on the contrary, the grove is the cause of the water being there. Drain off the water and the trees will remain, but cut off the trees, and the streams will vanish. Never was cause more completely mistaken for effect than in the case of these related phenomena of sequoia woods and perennial streams.
When attention is called to the method of sequoia stream-making, it will be apprehended at once. The roots of this immense tree fill the ground, forming a thick sponge that absorbs and holds back the rain and melting snow, only allowing it to ooze and flow gently. Indeed, every fallen leaf and rootlet, as well as long clasping root, and prostrate trunk, may be regarded as a dam hoarding the bounty of storm-clouds, and dispensing it as blessings all through the summer, instead of allowing it to go headlong in short-lived floods.
Since, then, it is a fact that thousands of sequoias are growing thriftily on what is termed dry ground, and even clinging like mountain pines to rifts in granite precipices, and since it has also been shown that the extra moisture found in connection with the denser growths is an effect of their presence, instead of a cause of their presence, then the notions as to the former extension of the species and its near approach to extinction, based upon its supposed dependence on greater moisture, are seen to be erroneous.
The decrease in rain and snowfall since the close of the glacial period in the Sierra is much less than is commonly guessed. The highest post-glacial water-marks are well preserved in all the upper river channels, and they are not greatly higher than the spring flood-marks of the present; showing conclusively that no extraordinary decrease has taken place in the volume of the upper tributaries of post-glacial Sierra streams since they came into existence. But, in the meantime, eliminating all this complicated question of climatic change, the plain fact remains that the present rain and snowfall is abundantly sufficient for the luxuriant growth of sequoia forests. Indeed, all my observations tend to show that in a prolonged drought the sugar pines and firs would perish before the sequoia, not alone because of the greater longevity of individual trees, but because the species can endure more drought, and make the most of whatever moisture falls.
Again, if the restriction and irregular distribution of the species be interpreted as a result of the desiccation of the Range, then instead of increasing as it does in individuals toward the south where the rainfall is less, it should diminish. If, then, the peculiar distribution of sequoia has not been governed by superior conditions of soil as to fertility or moisture, by what has it been governed?
In the course of my studies I observed that the northern groves, the only ones I was at first acquainted with, were located on just those portions of the general forest soil-belt that were first laid bare toward the close of the glacial period when the ice-sheet began to break up into individual glaciers. And while searching the wide basin of the San Joaquin, and trying to account for the absence of sequoia where every condition seemed favorable for its growth, it occurred to me that this remarkable gap in the sequoia belt fifty miles wide is located exactly in the basin of the vast, ancient mer de glace of the San Joaquin and Kings River basins which poured its frozen floods to the plain through this gap as its channel. I then perceived that the next great gap in the belt to the northward, forty miles wide, extending between the Calaveras and Tuolumne groves, occurs in the basin of the great ancient mer de glace of the Tuolumne and Stanislaus basins; and that the smaller gap between the Merced and Mariposa groves occurs in the basin of the smaller glacier of the Merced. The wider the ancient glacier, the wider the corresponding gap in the sequoia belt.
Finally, pursuing my investigations across the basins of the Kaweah and Tule, I discovered that the sequoia belt attained its greatest development just where, owing to the topographical peculiarities of the region, the ground had been best protected from the main ice-rivers that continued to pour past from the summit fountains long after the smaller local glaciers had been melted.
Taking now a general view of the belt, beginning at the south we see that the majestic ancient glaciers were shed off right and left down the valleys of Kern and Kings Rivers by the lofty protective spurs outspread embracingly above the warm sequoia-filled basins of the Kaweah and Tule. Then, next northward, occurs the wide sequoia-less channel, or basin of the ancient San Joaquin and sings River mer de glace; then the warm, protected spots of Fresno and Mariposa groves; then the sequoia-less channel of the ancient Merced glacier; next the warm, sheltered ground of the Merced and Tuolumne groves; then the sequoia-less channel of the grand ancient mer de glace of the Tuolumne and Stanislaus; then the warm old ground of the Calaveras and Stanislaus groves. It appears, therefore, that just where, at a certain period in the history of the Sierra, the glaciers were not, there the sequoia is, and just where the glaciers were, there the sequoia is not.
But although all the observed phenomena bearing on the post-glacial history of this colossal tree point to the conclusion that it never was more widely distributed on the Sierra since the close of the glacial epoch; that its present forests are scarcely past prime, if, indeed, they have reached prime; that the post-glacial day of the species is probably not half done; yet, when from a wider outlook the vast antiquity of the genus is considered, and its ancient richness in species and individuals, — comparing our Sierra Giant and Sequoia sempervirens of the Coast Range, the only other living species of sequoia, with the twelve fossil species already discovered and described by Heer and Lesquereux, some of which flourished over vast areas in the Arctic regions and in Europe and our own territories, during tertiary and cretaceous times — then, indeed, it becomes plain that our two surviving species, restricted to narrow belts within the limits of California, are mere remnants of the genus, both as to species and individuals, and that they may be verging to extinction. But the verge of a period beginning in cretaceous times may have a breadth of tens of thousands of years, not to mention the possible existence of conditions calculated to multiply and re-extend both species and individuals.
There is no absolute limit to the existence of any tree. Death is due to accidents, not, as that of animals, to the wearing out of organs. Only the leaves die of old age. Their fall is foretold in their structure; but the leaves are renewed every year, and so also are the essential organs wood, roots, bark, buds. Most of the Sierra trees die of disease, insects, fungi, etc., but nothing hurts the big tree. I never saw one that was sick or showed the slightest sign of decay. Barring accidents, it seems to be immortal. It is a curious fact that all the very old sequoias had lost their heads by lightning strokes. “All things come to him who waits.” But of all living things, sequoia is perhaps the only one able to wait long enough to make sure of being struck by lightning.
So far as I am able to see at present only fire and the ax threaten the existence of these noblest of God’s trees. In Nature’s keeping they are safe, but through the agency of man destruction is making rapid progress, while in the work of protection only a good beginning has been made. The Fresno grove, the Tuolumne, Merced and Mariposa groves are under the protection of the Federal Government in the Yosemite National Park. So are the General Grant and Sequoia National Parks; the latter, established twenty-one years ago, has an area of 240 square miles and is efficiently guarded by a troop of cavalry under the direction of the Secretary of the Interior; so also are the small General Grant National Park, estatblished at the same time with an area of four square miles, and the Mariposa grove, about the same size and the small Merced and Tuolumne group. Perhaps more than half of all the big trees have been thoughtlessly sold and are now in the hands of speculators and mill men. It appears, therefore, that far the largest and important section of protected big trees is in the great Sequoia National Park, now easily accessible by rail to Lemon Cove and thence by a good stage road into the giant forest of the Kaweah and thence by rail to other parts of the park; but large as it is it should be made much larger. Its natural eastern boundary is the High Sierra and the northern and southern boundaries are the Kings and Kern Rivers. Thus could be included the sublime scenery on the headwaters of these rivers and perhaps nine-tenths of all the big trees in existence. All private claims within these bounds should be gradually extinguished by purchase by the Government. The big tree, leaving all its higher uses out of the count, is a tree of life to the dwellers of the plain dependent on irrigation, a never-failing spring, sending living waters to the lowland. For every grove cut down a stream is dried up. Therefore all California is crying, “Save the trees of the fountains.” Nor, judging by the signs of the times, is it likely that the cry will cease until the salvation of all that is left of Sequoia gigantea is made sure.