the ancients told many wonderful legends concerning the tree, and claimed for it numerous extraordinary qualities. modern experience is finding some of these legends to be almost literal truth, and increasing knowledge of the tree shows that it has many of those high qualities for which it was anciently revered. though people no longer think of it as the tree of life, they are beginning to realize that the tree is what enables our race to make a living and to live comfortably and hopefully upon this beautiful world.
camping among forests quickly gives one a home feeling for them and develops an appreciation of their value. how different american history might have been had columbus discovered a treeless land! the american forests have largely contributed to the development of the country. the first settlers on the atlantic coast felled and used the waiting trees for home-[pg 124]building; they also used wood for fuel, furniture, and fortifications. when trading-posts were established in the wilderness the axe was as essential as the gun. from atlantic to pacific the pioneers built their cabins of wood. as the country developed, wood continued to be indispensable; it was used in almost every industry, and to-day it has a more general use than ever.
spanish moss at lake charles, louisiana spanish moss at lake charles, louisiana
forests enrich us in many ways. one of these is through the supply of wood which they produce,—which they annually produce. wood is one of the most useful materials used by man. wood is the home-making material. it gives good cheer to a million hearthstones. how extensively it is used for tools, furniture, and vehicles, for mine timbers and railroad development! the living influences which forests exert, the environments which they create and maintain, are potent to enable man best to manage and control the earth, the air, and the water, so that these will give him the greatest service and do him the least damage.
forests are water-distributors, and everywhere their presence tends to prevent both [pg 125] floods and extreme low water; they check evaporation and assist drainage; they create soil; they resist sudden changes of temperature; they break and temper the winds; they do sanitary work by taking impurities from the air; they shelter and furnish homes for millions of birds which destroy enormous numbers of weed-seed and injurious insects. lastly, and possibly most important, forests make this earth comfortable and beautiful. next to the soil, they are the most useful and helpful of nature's agencies.
forests are moderators of climate. they heat and cool slowly. their slow response to change resists sudden changes, and, consequently, they mitigate the rudeness with which sudden changes are always accompanied. sudden changes of temperature are often annoying and enervating to man, and frequently do severe damage to domestic plants and animals. they sometimes have what may be called an explosive effect upon the life-tissues of many plants and animals which man has domesticated and is producing for his benefit. many plants have been domesticated and largely so specialized that they have[pg 126] been rendered less hardy. with good care, these plants are heavy producers, but, to have from them a premium harvest each year, they need the genial clime, the stimulating shelter, and the constant protection which only forests can supply. closely allied to changes of temperature is the movement of the air. in the sea every peninsula is a breakwater: on land every grove is a windbreak. the effect of the violence of high winds on fruited orchards and fields of golden grain may be compared to the beatings of innumerable clubs. hot waves and cold waves come like withering breaths of flame and frost to trees and plants. high winds may be mastered by the forest. the forest will make even the storm king calm, and it will also soften, temper, and subdue the hottest or the coldest waves that blow. forests may be placed so as to make every field a harbor.
the air is an invisible blotter that is constantly absorbing moisture. its capacity to evaporate and absorb increases with rapidity of movement. roughly, six times as much water is evaporated from a place that is swept[pg 127] by a twenty-five-mile wind as from a place in the dead calm of the forest. the quantity of water evaporated within a forest or in its shelter is many times less than is evaporated from the soil in an exposed situation. this shelter and the consequent decreased evaporation may save a crop in a dry season. during seasons of scanty rainfall the crops often fail, probably not because sufficient water has not fallen, but because the thirsty winds have drawn from the soil so much moisture that the water-table in the soil is lowered below the reach of the roots of the growing plants.
in the arid west the extra-dry winds are insatiable. in many localities their annual capacity to absorb water is greater than the annual precipitation of water. in "dry-farming" localities, the central idea is to save all the water that nature supplies, to prevent the moisture from evaporating, to protect it from the robber winds. forests greatly check evaporation, and professor l. g. carpenter, the celebrated irrigation engineer, says that forests are absolutely necessary for the interests of irrigated agricul[pg 128]ture. considering the many influences of the forest that are beneficial to agriculture, it would seem as though ideal forest environments would be the best annual assurance that the crops of the field would not fail and that the soil would most generously respond to the seed-sower.
so well is man served in the distribution of the waters and the management of their movements by the forests, that forests seem almost to think. the forest is an eternal mediator between winds and gravity in their never-ending struggle for the possession of the waters. the forest seems to try to take the intermittent and ever-varying rainfall and send the collected waters in slow and steady stream back to the sea. it has marked success, and one may say it is only to the extent the forest succeeds in doing this that the waters become helpful to man. possibly they may need assistance in this work. anyway, so great is the evaporation on the mountains of the west that john muir says, "cut down the groves and the streams will vanish." many investigators assert that only thirty per cent of the rainfall is returned by the rivers[pg 129] to the sea. evaporation—winds—probably carry away the greater portion of the remainder. afforestation has created springs and streams, not by increasing rainfall, although the forests may do this, but by saving the water that falls,—by checking evaporation. on some exposed watersheds the winds carry off as much as ninety per cent of the annual precipitation. it seems plain that wider, better forests would mean deeper, steadier streams. forests not only check evaporation, but they store water and guard it from the greed of gravity. the forest gets the water into the ground where a brake is put upon the pull of gravity. forest floors are covered with fluffy little rugs and pierced with countless tree-roots. so all-absorbing is the porous, rug-covered forest floor that most of the water that falls in the forest goes into the ground; a small percentage may run off on the surface, but the greater part settles into the earth and seeps slowly by subterranean drainage, till at last it bubbles out in a spring some distance away and below the place where the raindrops came to earth. the underground[pg 130] drainage, upon which the forest insists, is much slower and steadier than the surface drainage of a treeless place. the tendency of the forest is to take the water of the widely separated rainy days and dole it out daily to the streams. the forest may be described as a large, ever-leaking reservoir.
the forest is so large a reservoir that it rarely overflows, and seepage from it is so slow that it seldom goes dry. the presence of a forest on a watershed tends to give the stream which rises thereon its daily supply of water, whether it rains every day or not. by checking evaporation, the forest swells the volume of sea-going water in this stream, and thereby increases its water-power and makes it more useful as a deep waterway. forests so regulate stream-flow that if all the watersheds were forested but few floods would occur. forest-destruction has allowed many a flood to form and foam and to ruin a thousand homes. a deforested hillside may, in a single storm, loose the hoarded soil of a thousand years. deforestation may result in filling a river-channel and in stopping boats a thou[pg 131]sand miles downstream. by bringing forests to our aid, we may almost domesticate and control winds and waters!
one of the most important resources is soil,—the cream of the earth, the plant-food of the world. scientists estimate that it takes nature ten thousand years to create a foot of soil. this heritage of ages, though so valuable and so slowly created, may speedily be washed away and lost. forests help to anchor it and to hold it in productive places. every tree stands upon an inverted basket of roots and rootlets. rains may come and rains may go, but these roots hold the soil in place. the soil of forest-covered hillsides is reinforced and anchored with a webwork of the roots and rootlets of the forest. assisting in the soil-anchorage is the accumulation of twigs and leaves, the litter rugs on the forest floor. these cover the soil, and protect it from both wind and water erosion. the roots and rugs not only hold soil, but add to the soil matter by catching and holding the trash, silt, dust, and sediment that is blown or washed into the forest. the forest also creates new soil,[pg 132] enriches the very land it is using. trash on a forest floor absorbs nitrogenous matter from the air; every fallen leaf is a flake of a fertilizer; roots pry rocks apart, and this sets up chemical action. acids given off by tree-roots dissolve even the rocks, and turn these to soil. a tree, unlike most plants, creates more soil than it consumes. in a forest the soil is steadily growing richer and deeper.
birds are one of the resources of the country. they are the protectors, the winged watchmen, of the products which man needs. birds are hearty eaters, and the food which they devour consists mostly of noxious weed-seed and injurious insects. several species of birds feed freely upon caterpillars, moths, wood-lice, wood-borers, and other deadly tree-enemies. most species of birds need the forest for shelter, a home, and a breeding-place; and, having the forest, they multiply and fly out into the fields and orchards, and wage a more persistent warfare even than the farmer upon the insistent and innumerable crop-injuring weeds, and also the swarms of insatiable crop-devouring insects.[pg 133] birds work for us all the time, and board themselves most of the time. birds are of inestimable value to agriculture, but many of these useful species need forest shelter. so to lose a forest means at the same time to lose the service of these birds.
the forest is a sanitary agent. it is constantly eliminating impurities from the earth and the air. trees check, sweep, and filter from the air quantities of filthy, germ-laden dust. their leaves absorb the poisonous gases from the air. roots assist in drainage, and absorb impurities from the soil. roots also give off acids, and these acids, together with the acids released by the fallen, decaying leaves, have a sterilizing effect upon the soil. trees help to keep the earth sweet and clean, and water which comes from a forested watershed is likely to be pure. many unsanitary areas have been redeemed and rendered healthy by tree-planting.
numerous are the products and the influences of the trees. many medicines for the sick-room are compounded wholly or in part from the bark, the fruit, the juices, or the leaves of trees.[pg 134] fruits and nuts are at least the poetry of the dining-table. one may say of trees what the french physician said of water: needed externally, internally, and eternally! united we stand, but divided we fall, is the history of peoples and forests. forest-destruction seems to offer the speediest way by which a nation may go into decline or death. "without forests" are two words that may be written upon the maps of most depopulated lands and declining nations.
when one who is acquainted with both history and natural history reads of a nation that "its forests are destroyed," he naturally pictures the train of evils that inevitably follow,—the waste and failure that will come without the presence of forests to prevent. he realizes that the ultimate condition to be expected in this land is a waste of desolate distances, arched with a gray, sad sky beneath which a few lonely ruins stand crumbling and pathetic in the desert's drifting sand.
the trees are our friends. as an agency for promoting and sustaining the general welfare, the forest stands pre?minent. a nation which[pg 135] appreciates trees, which maintains sufficient forests, and these in the most serviceable places, may expect to enjoy regularly the richest of harvests; it will be a nation of homes and land that is comfortable, full of hope, and beautiful.
