382 APPENDIX 



stands as well as for the forestation of uncultivated lands. The Touring Club of France 

 should be cited as a special example. Numerous governments are instituting Arbor 

 Days. In solemnly planting trees with their own hands, the kings of Spain, Italy and 

 England, and high government officials in the United States are merely imitating an 

 example given by our societies or by the ancestral custom, observed in certain com- 

 munes of Alsace, of planting at least one tree at the birth of each child. There also, 

 newly married couples plant two fir trees on the day of their marriage. . . . The 

 tree which grows in humanity which is increasing. The instinctive cultivation and 

 religious admiration of primitive peoples for the trees is based on science and reason. 



Physical Role of Forests. — Humidity. — Forests increase the degree of humidity 

 in the air. Not only are the arid zones sheltered by forests . . . but furthermore, 

 in the majority of cases, the presence of a vegetative mantle on the mountains is of 

 importance in the yield of crops and favors life and populations. Here the forestation, 

 true talisman of life, becomes a work of safety, and a question to be or not to be. All 

 floods have their rise on the bare ground created by the destructive felling of timber 

 which protects it. In these regions the forest disappears even though it is indispensable 

 to agricultural crops, the foundation of human life. It is on account of aridity alone, 

 and not for any other reason, that there have been terrible famines in Russia, in India, 

 and in China. Deforestation dries up a country. Without water there can be no life, 

 without humidity the ground will become as dead as the moon, and forests are necessary 

 in order to have water. Since their deforestation . . . Columbia, the Islands of 

 Maurice, of Reunion, and of Ascension, Sicily, Asia Minor and all other denuded regions 

 have experienced terrible droughts. These droughts immediately stopped in localities 

 where tree growth has been reestablished. In Porto Rico and in Jamaica, the phenome- 

 non is doubly verified in recent times. The rains disappear with the trees but return 

 with them. Above the forests there are light clouds, and after the shower the branches 

 drip onto the soil. . . . During the night the trees water the heather as if the urns 

 of the sky were thinking of the earth in order to fill up the divine springs. We have seen 

 all that and have concluded that the forest is the mother of the waters. But figures will 

 suffice to give an idea of the strength of the forest: an acre of high forest pumps every 

 day into the soil 10,000 to 12,000 quarts of reserve water; its evaporation can be placed 

 at 2,616 cubic yards per year representing a stream 20 inches high or almost three- 

 fourths the total rainfall falling in France. The quantity of liquid emitted by 

 the same area of water, mineral substance or vegetable substance are in the proportion 

 of 1, 3, and 60. The forest is certainly a reservoir of humidity. It is also a regulator. 

 While running water is often dangerous, its infiltration is desirable for the life of 

 springs. This infiltration attains its maximum under forest stands. The cover of 

 trees (doubled by a brush under story) largely reduces evaporation. Under the forest 

 the soil is better irrigated than on bare soil. On the other hand, the snow falls more 

 slowly, consequently the absorption of the forested land is perfect. The forest tends 

 to make the temperature more uniform by reducing the extremes of heat or cold. It 

 exercises the same action as does the sea at the seashore. On limestone soil, which forms 

 the major part of our planet, the running water digs out the soil and is then hidden by 

 these very fissures. Drought is accentuated, increasing the intensity of burning sands, 

 the bare steppes, and the arid deserts. It is a war of thirst, which menaces the twenti- 

 eth century. The forest alone by the shelter of its thick layer of humus is capable of 

 making a successful fight against the bankruptcy of the waters. 



Hail. — The trees diminish the storms, lessening electric discharges and rendering 

 less frequent and less dangerous the fall of hail, which in the deforested regions cuts 

 and damages the crops. Numerous examples have been established. In eighteen 

 departments, where the hail is usually the most damaging, fourteen are the least forested 

 in France. 



