222 AGRICULTURE AND FORESTRY. 



5. Zone of Dwai'f-pine, from 5. Zone of the mountain 



2,000 meters upward,* the region Divarfpine, 2,400 to 2,800 meters 

 of creeping Ericineae and high high. Here the Pinus parviflora 

 Alpine herbs. finds its home and the dwarfed 



Alnus viridis, Sorbus aucuparia, 

 Betula alba, Alnus firma, etc. 

 also appear. 



The great influence of forests upon climate has been repeatedly 

 called in question, but still more often abundantly attested. A 

 short, appropriate statement of the relation between them, based 

 on reliable observations, and from so competent an authority as 

 the Russian meteorologist A. Woeikof, in Petermann's Reports,^ was 

 surely therefore welcome to many. The result of the investigation 

 justifies the ruling, and among our foresters the unvarying opinion, 

 that forests have really a strong climatic influence upon the 

 country. The most eminent French savants have applied them- 

 selves to the question of reclothing the mountains of southern 

 France and Algiers with forests, and have come to the conclusion 

 that the cultivation of forests and all forms of vegetation has a 

 powerful effect upon climate. They purify the air, cool it in 

 summer, moderate the cold in winter, in many cases condense the 

 moisture of the atmosphere,^ and cause the greatest variety of 

 rainfall. They suck up snow-water and rain ^ into their leaves, 

 moss, and decaying matter, like the dry spongy turf They 

 lessen the formation of clefts in the ground by erosion and floods. 

 On the one hand, they hinder the flooding of valleys in the time of 

 heavy rains and melting of the snow ; and on the other, the water 

 they draw in and store away is given out gradually and feeds the 

 springs in the dry season. Thus the forest becomes a water 

 reservoir and an inexhaustible source of moisture, through which 

 the depth of rivers is regulated and maintained. 



The consequences of forest destruction show themselves not 

 only in the failure of wood for fuel, building, and manufacture, 

 but in still greater degree in the very considerable climatic changes 

 which the country undergoes. 



The destruction of forests causes an increase of the mean annual 

 temperature, especially of summer heat, as well as a decrease of 

 the annual rainfall. But to consider this as generally the cause 

 of floods would be to judge too partially. Floods are known in the 

 most densely wooded parts of the earth, especially in the heavily 

 wooded districts of Japan. The terrible overflow of the Rhine in 

 1882 occurred in one of the richest forest districts of the central 



1 Petermann's " Mitth." 31 Bd. 1885, pp. 81-87. 



' Every morsel of moss which we destroy, ana indeed all foliage, is a reservoir 

 for water. 



^ Forests do not attract the clouds, as has been popularly supposed, owing to 

 deceptive appearances, but produce them, by condensing the air which moves 

 through and over them. 



