RANGE IMPROVEMENT BY DEFERRED GRAZING. 9 



good deal by repeated trampling. As in the ease of the clipping- 

 experiments, the vegetation gradually weakened and no seed was 

 developed ; consequently there was no reproduction whatever. 



After the inclusion of the lands within the National Forests definite 

 grazing seasons were established, and not' only was depletion of the 

 range stopped, but there was a slight increase in its carrying capacity. 

 The improvement, however, was mainly confined to the lightly grazed 

 lands and was due almost entirely to the production of new shoots 

 from the root stalks of the original plants. Under the very best 

 conditions, however, the actual increase in forage by this means is 

 comparatively small, as the plants do not spread over bare areas. 



Yearlong or season-long grazing is the common practice in most 

 localities. For example, on the Wallowa National Forest sheep, the 

 only class of stock grazed in the high mountains, are allowed to 

 enter early in July as soon as growth is well started and when the 

 flower stalks of the vigorous plants are being sent up. At this time 

 the stalks are succulent and are eaten with about the same relish as 

 the herbage. The areas grazed earliest are occasionally cropped 

 again after the second herbage crop has partly developed. In such 

 cases the vegetation is again deprived of its food-manufacturing 

 parts. Even though grazed but once during the early stage of 

 development the range plants are unable to recover and reproduce. 

 Careful observations made in the case of 300 experimental areas on 

 the important forage types showed (1) that the palatable and de- 

 pendable perennial plants were not reproducing at all; (2) that only 

 one perennial herb, known as sickle sedge (Carex umbellata brevios- 

 tris), an unpalatable and useless species, was reproducing; and (3) 

 that unpalatable annual weeds which mature their seeds at about the 

 same time that the stock reach the mountain grazing lands, were 

 increasing at a rapid rate, especially on the most seriously depleted 

 areas. 



A relatively small percentage of this undesirable seedling stand 

 became established, however, because of the high moisture content 

 of the soil and the consequent ease with which the seedling roots of 

 the forage plants were pressed out of the ground by the early graz- 

 ing stock. In general, however, the loss in forage plants bore a 

 direct relation to the time that the lands were grazed, the greatest 

 loss occurring on the lands grazed earliest. 



To sum up the result from continued season-long grazing: Where 

 there is enough stock to use all the forage each year the requirements 

 of plant growth are seriously interfered with, the forage crop be- 

 comes weakened and is materially decreased, little or no seed is pro- 

 duced, reproduction is therefore prevented, and there is a gradual 

 decline in the carrying capacity of the range. 



