6 BULLETIN 1105, U. S. DEPARTMENT OF AGRICULTURE. 



In 1913 another series of areas was established for the purpose 

 of comparing results under different methods of cutting. They are 

 designated 5-1, 5-II, and 5-III. Seven sample plots of from 2 to 

 4 acres each were established within each area. The differences 

 in method of cutting are described in the chapter on this subject 

 (pp. 74-75). Soil and topography are similar to those of 

 plots 3a and 3b, excepting that the soil runs shallower on the 

 average. The altitude ranges from 7,200 to 7,400 feet. Herbaceous 

 vegetation is moderately dense and was closely grazed by cattle 

 and sheep up to the summer of 1919, when representative portions 

 of each area were fenced. A few horses graze within the inclosures, 

 but the outside is still open to cattle and sheep. Because of the 

 comparatively short period which has elapsed since the estab- 

 lishment and fencing of these plots, and because of their distance 

 (30 miles) from the experiment station, they have not been studied 

 so intensively with respect to reproduction as some of the older 

 plots near the station. 



PROGRESS OF REPRODUCTION ON SAMPLE PLOTS. 



The progress of reproduction on sample plots established in 1909, 

 as shown in Tables 1 to 4, is characteristic of cut-over areas on the 

 Coconino and Tusayan National Forests. Table 1 gives results of 

 extensive surveys, including only seedlings 1 foot or more in height 

 but covering the total area of 40 acres. Plots having considerable 

 numbers of seedlings in 1909 are omitted. Table 2 shows the dis- 

 tribution of age classes for seedlings 3 years and over on plots 3a 

 and 3b. This table is based upon a study covering 8 plots of 0.1 

 acre each within these two areas. Tables 3 and 4 concern primarily 

 the small seedlings from 1 to 5 years of age. A study of these tables 

 impresses one with the extreme slowness and uncertainty which char- 

 acterizes the reproduction of western yellow pine in this region. 

 The high infant mortality here indicated has been found to prevail 

 generally during the entire period in which studies have been car- 

 ried on. Time and again promising stands of young seedlings have 

 been almost completely wiped out during the first or even the sec- 

 ond season. The conclusion first drawn from these records was that 

 nothing could come of the light seedling crops which usually appear 

 every two or three years, and that the only way to secure repro- 

 duction was to wait for extraordinarily favorable conditions. This 

 is probably true of plots 4a and 4b, because the cinder cover renders 

 germination extremely difficult. Studies of age classes on areas 

 which had made some progress in reproduction, however, gradually 

 evolved the theory, first expressed in 1917, that, despite the almost 

 complete disappearance of seedling crops in the early stages, enough 

 will survive so that after about 20 years a given area if properly 



