r 



REPRODUCTION OF WESTERN YELLOW PINE. 5 



are indicated (Fig. 1). On smaller plots within the larger ones all 

 seedlings have been marked with number tags since 1913, and their 

 condition has. with a few exceptions, been recorded from one to three 

 times each year. In addition to the reproduction studies, the 

 diameter, height, and condition of each tree above 4 inches in diam- 

 eter is recorded every fifth year. 



Since repeated reference will be made to various plots in this 

 bulletin, brief descriptions are in order. 



DESCRIPTION OF SAMPLE PLOTS. 



1A and IB. — Established 1909; areas 6.1 and 10 acres, respectively; 

 private cutting about 1894; seed trees 3 to 4 per acre; soil basaltic 

 loamy clay, mostly stony; topography gently rolling; altitude 7,300 

 feet : ground cover moderately dense, mainly grasses, closely grazed 

 by cattle and horses. Both plots are fenced against sheep. Plot 

 1a is almost completely restocked and plot 1b about half restocked 

 with seedlings 5 to 25 years old. 



2 A and 2B. — Established 1909; areas 7 and 4.9 acres, respectively; 

 private cutting about 1895; seed trees 6 to 8 per acre; topography 

 gently rolling; altitude 7.300 feet; soil of volcanic origin, but de- 

 cidedly more gravelly than on plots 1a and 1b. Both plots are 

 fenced against grazing, but sheep and cattle graze all around them. 

 Keproduction is almost complete, ranging from 5 to 30 years old. 



3 A and SB. — Established 1909 ; areas 12 acres each ; Forest Service 

 cutting 1909, brush piled but not burned ; seed trees 5 to 8 per acre 

 (see Table 19); altitude 7,300 feet; topography gently rolling; 

 soil heavy clay loam derived from basalt; ground cover heavy bunch 

 grass, fenced, not grazed; sheep and cattle grazing outside. Both 

 plots are somewhat more than half restocked with seedlings which 

 have originated entirely since the plots were fenced 12 years ago; 

 therefore they furnish a striking contrast with the surrounding 

 areas which are almost destitute of reproduction. These plots are 

 typical of the areas on which the reproduction problem is most 

 critical. For this reason and because of their accessibility from the 

 experiment station they have met the requirements of this study 

 more fully than any of the other plots. 



4A and 4B. — Established in 1909 ; areas 8 acres each ; Forest Serv- 

 ice cutting 1909, brush piled but not burned; soil mostly a stiff 

 clay covered by volcanic cinders; topography gently rolling; alti- 

 tude 6,800 feet; ground cover generally sparse, mainly grasses, 

 lightly grazed by cattle and sheep, reproduction deficient. These 

 plots represent the cinder region of the Coconino, which is of limited 

 extent. 



The annual precipication is about 24 inches on all the foregoing 

 plots, except 4a and 4b, which probably receive 2 or 3 inches less. 



