68 BULLETIN 1105, U. S. DEPAKTMENT OF AGEICULTURE. 



RESULTS ON CUT-OVER LANDS. 



1909-1918. 



For many years an effort has been maintained to determine the 

 effects of different methods and degrees of cutting upon reproduc- 

 tion by direct comparison of results as shown by progress in re- 

 stocking. Cut-over areas on the Coconino and Tusayan National 

 Forests do not, as a rule, lend themselves well to such studies, for 

 the reason that the operation of natural factors is obscured by the 

 damage due to sheep grazing, with the result that reproduction dur- 

 ing the past 10 or 15 years has failed uniformly. This difficulty 

 has been met on local areas by fencing. Three areas were fenced in 

 1908, six in 1910-11, and two in 1919. In addition, a considerable 

 nmnber of privately owned pastures grazed only by cattle and horses 

 are scattered through the forest. 



As shown by Tables 1 to 4 and the accompanying discussion under 

 "Studies on permanent sample plots," reproduction even on areas 

 protected against sheep progressed with extreme slowness during the 

 10 years prior to 1919. Nevertheless, two of these areas, 3a and 3b, 

 cut by the group-selection method and representative of the bunch- 

 grass type in a locality where reproduction is generally very poor, 

 show at the end of 11 years an average of 222 seedlings per acre 

 from 4 to 11 years of age. Areas on which reproduction progresses 

 at this rate should be fairly well stocked at the end of 20 years, 

 assuming for complete stocking a minimum of 200 seedlings per acre 

 10 or more years of age.^* Moreover, it is almost certain, in the light 

 of recent investigations, that with proper control of ground cover 

 the rate indicated above will be exceeded. It is also to be considered 

 that the large seedling crop of 1919, of which about Y,000 per acre 

 remained on sample plots 3a and 3b at the end of three years, has 

 not been taken into account. 



The above results are equaled or excelled on dozens of fenced areas 

 in different parts of the forest. In two instances complete stocking 

 of over 1,000 seedlings per acre, now over a foot in height, was 



"The determination of what constitutes complete reproduction of western yellow pine 

 in this region has always been a perplexing problem. Stands of 1,000 or more even- 

 aged seedlings per acre would be desirable, but obseiwations indicate that in many in- 

 stances we will have to be content with less. Denser stocking will be obtained only 

 when there happens to be an unusually favorable combination of seed and rainfall. Such 

 occurrences are so rare and uncertain that they can not be depended upon. It is 

 believed that out of a stand of 200 10-year seedlings per acre there will be sufficient sur- 

 vival to give a stocking at least as good as the original stand. It must be expected, how- 

 ever, that on all but the most favorable sites fail spots from 50 to 100 feet in diameter, 

 due to heavy soil, dense grass, or other adverse conditions, will be of common occur- 

 rence. Such openings do not represent a total waste, because they are permeated by 

 the roots of surrounding trees as much as 100 feet distant. There is reason to believe 

 that the present group formation will persist in future stands unless we resort to plant- 

 ings or other artificial aids to natural reproduction. 



