Southern Appalachian Digital Collections

Western Carolina University (20) View all

Report of the Secretary of Agriculture in relation to the forests, rivers, and mountains of the southern Appalachian region

items 267 of 386 items
  • wcu_great_smoky_mtns-8741.jpg
Item
?

Item’s are ‘child’ level descriptions to ‘parent’ objects, (e.g. one page of a whole book).

  • SOUTHERN APPALACHIAN REGION. 121 they contain have maintained the greatest elevations presented in this region. Of this the mighty domes of the Smokies, the Balsams, and the Roan, and the lofty peaks of the Blacks, are witnesses. (PI. LXVL) The moist atmosphere is conducive to the rapid decay graSon. disiute~ of the rocks, which break up chiefly under the attack of rain, frost, the roots of the trees, the underground waters, and organic acids. At first decay works in along the various partings, resulting in the loosening of large masses, which gradually become smaller, until finally nothing is left of them except clay and the more obdurate bits of rock. The rocks reach the surface only over very small patches, while in places the disintegration attains a depth as great as 50 feet. On sloping surfaces the loose material is maintained in its place solely by friction. When this is lessened or overcome from any cause, the residual matter, be it clay or rock fragments, slides down the slopes until the friction is again sufficient to retain it in one position. Thus are formed immense thicknesses of loose material washed down from steep slopes and accumulated in the hollows and flatter places. This material gradually works its way downhill as it is pushed along by the freezing of the water which it contains, or is rendered more unstable as the water transforms it into mud. Eventually it finds its way into the streams and is carried by slow stages into the sea. (PI. LXVII.) PROTECTION OF THE SOILS. The chief agent which checks this process of removal is the forest cover, even though the penetrating roots and the acids due to vegetation induce rock decomposition. These same roots, however, hold the loose material in place and hinder its tendency to slide downhill. With this^R^ou^nd assistance loose soils are upheld on slopes at angles fully the *>«• double those which they could maintain unaided. Besides this direct check to the waste of slopes by increased friction, the action of the forests is as great in another way. Loose materials are washed downhill during rainstorms by even the tiniest rivulets. In open fields these gather in a few minutes and form deeper and deeper channels with each succeeding storm, finally removing the loose material down to the bare rock. This process is almost wholly prevented by the network of roots and the cover of leaves, both living and dead, and the water concentrates into rivulets by seeping through the soils so slowly that it carries no
Object
?

Object’s are ‘parent’ level descriptions to ‘children’ items, (e.g. a book with pages).