

REPLACEMENT OF FOREST HY NATURE. 69 



the air over the denuded area, burns fiercely, and windfalls, standing 

 dead trees, and young growth are all swept away together, leaving 

 nothing but a light covering of ashes and a few blackened stumps. 



In the Yellow Pine section, as before explained, the trees are not 

 tire-killed as extensively as in the other sections, but the action on the 

 young growth is the same. The second lire therefore frustrates any 

 attempt of nature to replace the cut off or burned up older growth by 

 a new one. 



The forest is replaced by nature abundantly and surely if not inter- 

 fered with. Within a few months after a "first burn" of a forest area 

 in the White Pine Zone, there will be seen young plants of various 

 species of willow and ceanothus springing up in great numbers from 

 the denuded soil. In places where the humus was not totally destroyed 

 seedlings of different kinds of conifers which grew nearest the burned 

 area begin to show themselves. After three or four years the shed and 

 decaying leaves of the willows, ceanothi, and the annuals that are com- 

 ing in have formed a very thin humus, which appears to be essential to 

 the germination of the seeds of the conifers, which now increase rapidly, 

 and in a few years the shrubby vegetation has given place to a thriving 

 young growth of trees. At the same time most of the dead timber 

 killed by the previous hie has fallen down. 



When the timber is removed by a second burning, the barren soil 

 parts more readily with its moisture. Owing to this cause many places, 

 especially those witli a southern exposure, become too dry after a fire 

 to again allow the growth of conifers. We find such places everywhere 

 along the valley of the South Pork, the upper St. Mary, and in the 

 zones of the Subalpine Fir and the Crest Pine. The wide expanses of 

 grassy slopes at high elevations are probably due to the exsiccated 

 nature of the soil during the summer months. One sees old burned 

 stumps in many localities at these elevations, and their presence proves 

 incontrovertibly the existence of a heavier forest growth in past times. 



It would be practically impossible for human efforts to replant suc- 

 cessfully any considerable portion of the burned forest tracts in the 

 Cceur d'Alenes. In the first place, the ground must be sheltered from 

 the direct rays of the sun, not only to permit the germination of the 

 seed, but also to retain a sufficiency of moisture during the dry season. 

 Next, the seedlings or saplings must stand close enough to resist the 

 crushing effects of the great quantities of snow piled on them during 

 the winter. < >bservation proves that a dense growth does not suffer in 

 the aggregate from this cause as much as one that is open. 



On an acre of ground in one of the sections where the forest is in 

 process of restoration a half million seedlings P~> cm. to L'O cm. (<> to 8 

 inches) high is a common occurrence. On shady slopes with a northern 

 exposure 1 have seen them set so closely that every acre bore millions. 

 Young trees 4 to 5 meters (Pi to Pi feet) high form such dense groves 

 in many places that it is impossible to force one's way through them 



