The Spell of the Rockies Part 6

The outline of the other blaze was that of a flattened ellipse, like the orbit of many a wandering comet in the sky. This had gone before the wind, and the windward end of its...o...b..t closely encircled the place of origin. The camp-fire nucleus of this blaze had also been built in the wrong place,--against a fallen log which lay in a deep bed of decaying needles.

Of course each departing camper should put out his camp-fire. However, a camp-fire built on a humus-covered forest floor, or by a log, or against a dead tree, is one that is very difficult to extinguish. With the best of intentions one may deluge such a fire with water without destroying its potency. A fire thus secreted appears, like a lie, to have a spark of immortality in it.

A fire should not be built in contact with substances that will burn, for such fuel will prolong the fire's life and may lead it far into the forest. There is but little danger to the forest from a fire that is built upon rock, earth, sand, or gravel. A fire so built is isolated and it usually dies an early natural death. Such a fire--one built in a safe and sane place--is easily extinguished.

The larger of these two incipient fires was burning quietly, and that night I camped within its...o...b..t. Toward morning the wind began to blow, this slow-burning surface fire began to leap, and before long it was a crown fire, traveling rapidly among the tree-tops. It swiftly expanded into an enormous delta of flame. At noon I looked back and down upon it from a mountain-top, and it had advanced about three miles into a primeval forest sea, giving off more smoke than a volcano.

I went a day's journey and met a big fire that was coming aggressively forward against the wind. It was burning a crowded, stunted growth of forest that stood in a deep litter carpet. The smoke, which flowed freely from it, was distinctly ashen green; this expanded and maintained in the sky a smoky sheet that was several miles in length.

Before the fire lay a square mile or so of old burn which was covered with a crowded growth of lodge-pole pine that stood in a deep, criss-crossed entanglement of fallen fire-killed timber. A thousand or more of these long, broken dead trees covered each acre with wreckage, and in this stood upward of five thousand live young ones. This would make an intensely hot and flame-writhing fire. It appears that a veteran spruce forest had occupied this burn prior to the fire. The fire had occurred fifty-seven years before. Trees old and young testified to the date. In the margin of the living forest on the edge of the burn were numerous trees that were fire-scarred fifty-seven years before; the regrowth on the burn was an even-aged fifty-six-year growth.

That night, as the fire neared the young tree growth, I scaled a rock ledge to watch it. Before me, and between the fire and the rocks, stood several veteran lodge-pole pines in a ma.s.s of dead-and-down timber. Each of these trees had an outline like that of a plump Lombardy poplar. They perished in the most spectacular manner.

Blazing, wind-blown bark set fire to the fallen timber around their feet; this fire, together with the close, oncoming fire-front, so heated the needles on the lodge-poles that they gave off a smoky gas; this was issuing from every top when a rippling rill of purplish flame ran up one of the trunks. Instantly there was a flash and white flames flared upward more than one hundred feet, stood gus.h.i.+ng for a few seconds, and then went out completely. The other trees in close succession followed and flashed up like giant geysers discharging flame. This discharge was brief, but it was followed by every needle on the trees glowing and changing to white incandescence, then vanis.h.i.+ng. In a minute these leafless lodge-poles were black and dead.

The fire-front struck and crossed the lodge-pole thicket in a flash; each tree flared up like a fountain of gas and in a moment a deep, ragged-edged lake of flame heaved high into the dark, indifferent night. A general fire of the dead-and-down timber followed, and the smelter heat of this cut the green trees down, the flames widely, splendidly illuminating the surrounding mountains and changing a cloud-filled sky to convulsed, burning lava.

Not a tree was left standing, and every log went to ashes. The burn was as completely cleared as a fireswept prairie; in places there were holes in the earth where tree-roots had burned out. This burn was an ideal place for another lodge-pole growth, and three years later these pines were growing thereon as thick as wheat in a field. In a boggy area within the burn an acre or two of aspen sprang up; this area, however, was much smaller than the one that the fire removed from the bog. Aspens commonly hold territory and extend their holdings by sprouting from roots; but over the greater portion of the bog the fire had either baked or burned the roots, and this small aspen area marked the wetter part of the bog, that in which the roots had survived.

After destroying the lodge-pole growth the fire pa.s.sed on, and the following day it burned away as a quiet surface fire through a forest of scattered trees. It crept slowly forward, with a yellow blaze only a few inches high. Here and there this reddened over a pile of cone-scales that had been left by a squirrel, or blazed up in a pile of broken limbs or a fallen tree-top; it consumed the litter mulch and fertility of the forest floor, but seriously burned only a few trees.

Advancing along the blaze, I came upon a veteran yellow pine that had received a large pot-hole burn in its instep. As the Western yellow pine is the best fire-fighter in the conifer family, it was puzzling to account for this deep burn. On the Rocky Mountains are to be found many picturesque yellow pines that have a dozen times triumphed over the greatest enemy of the forest. Once past youth, these trees possess a thick, corky, asbestos-like bark that defies the average fire. Close to this injured old fellow was a rock ledge that formed an influential part of its environment; its sloping surface shed water and fertility upon its feet; cones, twigs, and trash had also slid down this and formed an inflammable pile which, in burning, had bored into its ankle. An examination of its annual rings in the burned hole revealed the fact that it too had been slightly burned fifty-seven years before. How long would it be until it was again injured by fire or until some one again read its records?

Until recently a forest fire continued until stopped by rain or snow, or until it came to the edge of the forest. I have notes on a forest fire that lived a fluctuating life of four months. Once a fire invades an old forest, it is impossible speedily to get rid of it. "It never goes out," declared an old trapper. The fire will crawl into a slow-burning log, burrow down into a root, or eat its way beneath a bed of needles, and give off no sign of its presence. In places such as these it will hibernate for weeks, despite rain or snow, and finally some day come forth as ferocious as ever.

About twenty-four hours after the lodge-pole blaze a snow-storm came to extinguish the surface fire. Two feet of snow--more than three inches of water--fell. During the storm I was comfortable beneath a shelving rock, with a fire in front; here I had a meal of wild raspberries and pine-nuts and reflected concerning the uses of forests, and wished that every one might better understand and feel the injustice and the enormous loss caused by forest fires.

During the last fifty years the majority of the Western forest fires have been set by unextinguished camp-fires, while the majority of the others were the result of some human carelessness. The number of preventable forest fires is but little less than the total number.

True, lightning does occasionally set a forest on fire; I have personal knowledge of a number of such fires, but I have never known lightning to set fire to a green tree. Remove the tall dead trees from forests, and the lightning will lose the greater part of its kindling.

In forest protection, the rivers, ridge-tops, rocky gulches, rock-fields, lake-sh.o.r.es, meadows, and other natural fire-resisting boundary lines between forests are beginning to be used and can be more fully utilized for fire-lines, fire-fighting, and fire-defying places. These natural fire-barriers may be connected by barren cleared lanes through the forest, so that a fire-break will isolate or run entirely around any natural division of forest. With such a barrier a fire could be kept within a given section or shut out of it.

In order to fight fire in a forest it must be made accessible by means of roads and trails; these should run on or alongside the fire-barrier so as to facilitate the movements of fire patrols or fire-fighters.

There should be with every forest an organized force of men who are eternally vigilant to prevent or to fight forest fires. Fires should be fought while young and small, before they are beyond control.

There should be crows'-nests on commanding crags and in each of these should be a lookout to watch constantly for starting fires or suspicious smoke in the surrounding sea of forest. The lookout should have telephonic connection with rangers down the slopes. In our national forests incidents like the following are beginning to occur: Upon a summit is stationed a ranger who has two hundred thousand acres of forest to patrol with his eyes. One morning a smudgy spot appears upon the purple forest sea about fifteen miles to the northwest. The lookout gazes for a moment through his gla.s.s and, although not certain as to what it is, decides to get the distance with the range-finder.

At that instant, however, the wind acts upon the smudge and shows that a fire exists and reveals its position. A ranger, through a telephone at the forks of the trail below, hears from the heights, "Small fire one mile south of Mirror Lake, between Spruce Fork and Bear Pa.s.s Trail, close to O'Brien's Spring." In less than an hour a ranger leaps from his panting pony and with shovel and axe hastily digs a narrow trench through the vegetable mould in a circle around the fire. Then a few shovelfuls of sand go upon the liveliest blaze and the fire is under control. As soon as there lives a good, sympathetic public sentiment concerning the forest, it will be comparatively easy to prevent most forest fires from starting and to extinguish those that do start.

With the snow over, I started for the scene of the first fire, and on the way noticed how much more rapidly the snow melted in the open than in a forest. The autumn sun was warm, and at the end of the first day most of the snow in open or fireswept places was gone, though on the forest floor the slushy, compacted snow still retained the greater portion of its original moisture. On the flame-cleared slopes there was heavy erosion; the fire had destroyed the root-anchorage of the surface and consumed the trash that would ordinarily have absorbed and delayed the water running off; but this, unchecked, had carried off with it tons of earthy material. One slope on the first burn suffered heavily; a part of this day's "wash" was deposited in a beaver pond, of half an acre, which was filled to the depth of three feet. The beavers, finding their subterranean exits filled with wash, had escaped by tearing a hole in the top of their house.

Leaving this place, I walked across the range to look at a fire that was burning beyond the bounds of the snowfall. It was in a heavily forested cove and was rapidly undoing the constructive work of centuries. This cove was a horseshoe-shaped one and apparently would hold the fire within its rocky ridges. While following along one of these ridges, I came to a narrow, tree-dotted pa.s.s, the only break in the confining rocky barrier. As I looked at the fire down in the cove, it was plain that with a high wind the fire would storm this pa.s.s and break into a heavily forested alpine realm beyond. In one day two men with axes could have made this pa.s.s impregnable to the a.s.saults of any fire, no matter how swift the wind ally; but men were not then defending our forests and an ill wind was blowing.

Many factors help to determine the speed of these fires, and a number of observations showed that under average conditions a fire burned down a slope at about one mile an hour; on the level it traveled from two to eight miles an hour, while up a slope it made from eight to twelve. For short distances fires occasionally roared along at a speed of fifty or sixty miles an hour and made a terrible gale of flames.

I hurried up into the alpine realm and after half an hour scaled a promontory and looked back to the pa.s.s. A great cloud of smoke was streaming up just beyond and after a minute tattered sheets of flame were shooting high above it. Presently a tornado of smoke and flame surged into the pa.s.s and for some seconds nothing could be seen. As this cleared, a succession of tongues and sheets of flame tried to reach over into the forest on the other side of the pa.s.s, but finally gave it up. Just as I was beginning to feel that the forest around me was safe, a smoke-column arose among the trees by the pa.s.s. Probably during the first a.s.sault of the flames a fiery dart had been hurled across the pa.s.s.

Up the shallow forested valley below me came the flames, an inverted Niagara of red and yellow, with flying spray of black. It sent forward a succession of short-lived whirlwinds that went to pieces explosively, hurling sparks and blazing bark far and high. During one of its wilder displays the fire rolled forward, an enormous horizontal whirl of flame, and then, with thunder and roar, the molten flames swept upward into a wall of fire; this tore to pieces, collapsed, and fell forward in fiery disappearing clouds. With amazing quickness the splendid hanging garden on the terraced heights was crushed and blackened. By my promontory went this magnificent zigzag surging front of flame, blowing the heavens full of sparks and smoke and flinging enormous fiery rockets. Swift and slow, loud and low, swelling and vanis.h.i.+ng, it sang its eloquent death song.

A heavy stratum of tarlike smoke formed above the fire as it toned down. Presently this black stratum was uplifted near the centre and then pierced with a stupendous geyser of yellow flame, which reddened as it fused and tore through the tarry smoke and then gushed astonis.h.i.+ngly high above.

A year or two prior to the fire a snow slide from the heights had smashed down into the forest. More than ten thousand trees were mowed, raked, and piled in one mountainous ma.s.s of wreckage upon some crags and in a narrow-throated gulch between them. This wood-pile made the geyser flames and a bonfire to startle even the giants. While I was trying to account for this extraordinary display, there came a series of explosions in rapid succession, ending in a violent cras.h.i.+ng one.

An ominous, elemental silence followed. All alone I had enjoyed the surprises, the threatening uncertainties, and the dangerous experiences that swiftly came with the fire-line battles of this long, smoky war; but when those awful explosions came I for a time wished that some one were with me. Had there been, I should have turned and asked, while getting a better grip on my nerves, "What on earth is that?" While the startled mountain-walls were still shuddering with the shock, an enormous agitated column of steam shot several hundred feet upward where the fiery geyser had flamed. Unable to account for these strange demonstrations, I early made my way through heat and smoke to the big bonfire. In the bottom of the gulch, beneath the bonfire, flowed a small stream; just above the bonfire this stream had been temporarily dammed by fire wreckage. On being released, the acc.u.mulated waters thus gathered had rushed down upon the red-hot rocks and cliffs and produced these explosions.

In the morning light this hanging terraced garden of yesterday's forest glory was a stupendous charcoal drawing of desolation.

Insects in the Forest

Insects in the Forest

The big trees of California are never attacked by insects. This immunity is extraordinary and may be the chief characteristic that enables these n.o.ble trees to live so long. Unfortunately it is not shared by other species. The American forests are infested with thousands of species of injurious and destructive insects. These insects, like the forest fires, annually kill numerous forest areas, and in addition leave millions of deformed and sickly trees scattered through the living forest to impair and imperil it. After some general tree studies which have occupied odd times for years and extended through the groves and forests of every State and Territory in the Union, the conclusion has been forced upon me that the forests are more widely wasted by insects than by fire.

Some of Nature's strange ways are exhibited in the interrelation of insects and fires in tree-killing. It is common for the attack of one of these tree-enemies to open the way for the depredations of the other. The trees that insects kill quickly become dry and inflammable and ready kindling for the forest fire. On the other hand, the injuries that green trees often receive from forest fires render them most susceptible to the attacks of insects.

This interrelation--almost cooperation--between these arch-enemies of the forest was impressed upon me during my early tree studies. One day I enjoyed a splendid forest sea from the summit of a granite crag that pierced this purple expanse. Near the crag a few clumps of trees stood out conspicuous in robes of sear yellow brown. Unable to account for this coloring of their needles, I went down and looked them over. The trees had recently been killed by insects. They were Western yellow pine, and their needles, changed to greenish yellow, still clung to them. In each clump of these pines there were several stunted or deformed trees, or trees that showed a recent injury. The stunted and injured trees in these clumps were attacked and killed by beetles the summer before my visit. In these injured trees the beetles had multiplied, and they emerged the following summer and made a deadly attack upon the surrounding vigorous trees. Although this latter attack was made only a month or two before my arrival, the trees were already dead and their needles had changed to a sickly greenish yellow. Amid one of these clumps was a veteran yellow pine that lightning had injured a few years before. Beetles attacked and killed this old pine about a year before I appeared upon the scene. It was the only tree in this now dead clump that was attacked on that first occasion; but some weeks before my visit the beetles in multiplied numbers swarmed forth from it and speedily killed the sound neighboring trees.

These conclusions were gathered from the condition of the trees themselves together with a knowledge of beetle habits. Not a beetle could be found in the lightning-injured pine, and its needles were dry and yellow. The near-by dead pines were full of beetles and their eggs; the needles, of a greenish yellow, were slightly tough and still contained a little sap.

While I was in camp one evening, in the midst of these tree studies, the veteran pine, now dead, was again struck by lightning. As everything was drenched with rain, there appeared to be no likelihood of fire. However, the following morning the old pine was ablaze. In extinguis.h.i.+ng the fire I found that it had started at the base of the tree at a point where the bolt had descended and entered the earth. At this place there was an acc.u.mulation of bark-bits from the trunk, together with fallen twigs and needles from the dead tree-top. Thus a dead, inflammable tree in the woods is kindling which at any moment may become a torch and set fire to the surrounding green forest.

Although fires frequently sweep through and destroy a green forest, they commonly have their start among dead trees or trash.

The pine beetle just mentioned attacks and burrows into trees for the purpose of laying its eggs therein. When few in number they confine their attacks to trees of low vitality,--those that will easily succ.u.mb to their attack. The speedy death of the tree and the resultant chemical change in its sap appear to be necessary for the well-being of the deposited eggs or the youngsters that emerge from them. When these beetles are numerous they freely attack and easily kill the most vigorous of trees.

The pine beetle is one of a dozen species of bark beetles that are grouped under a name that means "killer of trees." Each year they kill many acres of forest, and almost every year some one depredation extends over several thousand acres. The way of each species is similar to that of the others. The beetles of each species vary in length from a tenth to a fifth of an inch. They migrate in midsummer, at the time of the princ.i.p.al attack. Swarming over the tree, they at once bore into and through the bark. Here short transverse or vertical galleries are run, and in these the eggs are laid.

In a short time the eggs hatch into grubs, and these at once start to feed upon the inner bark at right angles to the galleries, extending to right and left around the tree. It does not require many of them to girdle the tree. Commonly the tree is dead in two months or less. All these little animals remain in the tree until late spring or early summer, when they emerge in multiplied swarms and repeat the deadly work in other trees.

The depredations of these insects are enormous. During the early eighties the Southern pine beetle ruined several thousand acres of pines in Texas. Ten years later, 1890-92, it swarmed through western North Carolina, Virginia, and West Virginia to southern Pennsylvania and over an area aggregating seventy-five thousand square miles, and killed pines of all species and ages, leaving but few alive. Within the past few years the mountain and Western pine beetles have ruined a one-hundred-thousand-acre lodge-pole pine tract in northeastern Oregon, destroying not less than ninety per cent of the stand. During the past decade the Black Hills beetle has been active over the Rocky Mountains, where in some districts it has destroyed from ten to eighty per cent of the Western yellow pines. In the Black Hills the forests over several thousand square miles are ruined.

These bug-killed trees deteriorate rapidly. In most cases a beetle-killed pine is pretty well rotted in five years and usually falls to pieces in less than a decade. Borers attack upon the heels of the beetles, and the holes made by the beetles admit water and fungi into the wood. This rapidly reduces the wood to a punky, rotten ma.s.s.

One day in Colorado I tore a number of wind-wrecked, bug-killed trees to pieces and was busily engaged examining the numerous population of grubs and borers, when some robins and other birds discovered the feast, collected, and impatiently awaited their turn. Perceiving the situation, I dragged a fragment of a log to one side for examination while the birds a.s.sembled to banquet and dispute.

Returning to the rotten logs for another grub-filled fragment, I paused to watch some wasps that, like the birds, were feasting upon these grubs. A wasp on finding a grub simply thrust his snout into the grub and then braced himself firmly as he bored down and proceeded to suck his victim's fluids. In throwing a log to one side I disturbed a bevy of slender banqueters that I had not seen. Instantly a number of wasps were effervescing round my head. Despite busy arms, they effectively peppered my face, and I fled to a neighboring brook to bathe my wounds.

While I was at a safe distance, cogitating as to the wisdom of returning for further examination of the logs, a black bear appeared down the opening. From his actions I realized that he had scented not myself but the feast in the log-pile. After sniffling, pointing, and tip-toeing, he lumbered toward the logs. Of course I was curious as to the manner of his reception and allowed him to go unwarned to the feast. Two Rocky Mountain jays gave a low, indifferent call on his approach, but the other birds ignored his coming. With his fore paw he tore a log apart and deftly picked up a number of grubs. All went well until he climbed upon the pile of wreckage and rolled a broken log off the top. This disturbed another wasp feast. Suddenly he grabbed his nose with both fore paws and tumbled off the pile. For a few seconds he was slapping and battling at a lively pace; then, with a _woof-f-f-f!_ he fled--straight at me. I made a tangential move.

The hardwoods are also warred upon by bugs, weevils, borers, and fungi. The percentage of swift deaths, however, that the insects cause among the hardwoods is much smaller than that among the pines; but the percentage of diseased and slow-dying hardwoods is much greater. The methods of beetles that attack oaks, hickories, aspens, and birches are similar to the methods of those that attack pines and spruces.

They attack in swarms, bore through the bark, and deposit their eggs either in the inner bark or in the cambium,--the vitals of the tree.

The grubs, on hatching, begin to feed upon the tree's vitals. In this feeding each grub commonly drives a minute tunnel from one to several inches in length. Where scores of grubs hatch side by side they drive a score of closely parallel tunnels. Commonly these are either horizontal or vertical and generally they are numerous enough to make many complete girdles around the tree. Girdling means cutting off the circulation, and this produces quick death.

While these beetles are busy killing unnumbered millions of trees annually, the various species of another group of beetles known as weevils are active in deforming and injuring even a greater number.

They mutilate and deform trees by the millions. The work of the white-pine weevil is particularly devilish. It deposits its eggs in the vigorous shoots of the white-pine sapling. The eggs hatch, and the grubs feed upon and kill the shoot. Another shoot bursts forth to take the place of the one killed; this is attacked and either killed or injured. The result is a stunted, crooked, and much-forked tree.