. Bulletin of the Department of Agriculture. Agriculture; Agriculture. 22 BULLETIN 791, U. S. DEPARTMENT OF AGRICULTURE. If this is not done, the retrogression of the vegetation to a pure sec- ond-weed stage, or, indeed, to tiie first-weed stage, is inevitable. THE PORCUPINE-GRASS-YELLOW-BRUSH CONSOCIATION. As a result of the serious overgrazing in the Wasatch Mountains prior to the inclusion of the lands in the Wasatch Forest in 1905, the wheat-grass consociation was much injured in many localities. Where the fertility of the soil was not appreciably impaired after the de- struction of t
. Bulletin of the Department of Agriculture. Agriculture; Agriculture. 22 BULLETIN 791, U. S. DEPARTMENT OF AGRICULTURE. If this is not done, the retrogression of the vegetation to a pure sec- ond-weed stage, or, indeed, to tiie first-weed stage, is inevitable. THE PORCUPINE-GRASS-YELLOW-BRUSH CONSOCIATION. As a result of the serious overgrazing in the Wasatch Mountains prior to the inclusion of the lands in the Wasatch Forest in 1905, the wheat-grass consociation was much injured in many localities. Where the fertility of the soil was not appreciably impaired after the de- struction of the subclimax grass cover, the wheat grasses soon re- establish themselves; but where ap- preciable erosion took place or where a considerable proportion of the sol- uble soil nutrients was leached out, the wheat-grass species failed to re- occupy the lands. On the seriously impoverished soils, only a sparse stand of short-lived plants at first gained a foothold; but on areas where the fertility and the water-holding capacity of the soil were onlj- slightly impaired, grasses, notably small mountain porcupine grass {Stipa minor) (fig. 8), and its ever-present associate, yellow brush {Chrysotham- nus lanceolatus), predominated. Wliere the soil was more seriously depleted, blue grasses, fescues, brome grasses, and others were invariably associated with porcupine grass and yellow brush. After the destruction of tlie wheat- grass consociation by overgrazing, a large proportion of the entire cover was then either of the ea'rly or late weed stage; but as a result of correcting the destructive factor of overstocking, the porcupine-grass-j^ellow-brush type now constitutes the most extensive consociation of relatively high-carry- ing capacity in the high mountain region. Small mountain porcupme grass and the local congeneric species grow as bunch grass, and the intervening space is occupied by other grasses and nongrasslike plants. T\rhere the soil has undergone only slight change physica
Size: 1099px × 2274px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauth, bookcentury1900, bookdecade1910, booksubjectagriculture
