1 8 Forestry Quarterly. 



Pine, pure Douglas Fir, mixed Douglas Fir, mixed Spruce, Alpine 

 Fir. These types are based purely on composition of species. 

 Wherever at least 80 per cent, of the merchantable trees on a sam- 

 ple acre were of one species, the type was considered pure. 



Methods of Taking Observations. 



In estimating the method of strips, one chain in width was used, 

 calipering the trees 10 inches and above in diameter. At the end 

 of each acre or at the end of every loth chain, observations were 

 taken of the density on the scale of 10, and of the condition of re- 

 production, in square rod plots at mechanical intervals ; notes were 

 also taken of the ground cover, aspect, degree of slope, and con- 

 dition of the timber. Much better results were obtained by mak- 

 ing the intervals mechanically than if they had been taken by 

 some irregular method, since the presence or absence of repro- 

 duction is always liable to prejudice one in the choice of the plot 

 and prevent arriving at a fair general average. The survey strips 

 were run at right angles to the contours in each main stream 

 valley or principal canyon at one half mile intervals and were 

 run across every class of land and forest type up to the alpine 

 growth. Any seedling up to three feet in height was considered 

 reproduction. 



Reproduction in Open. 



It is well known and generally conceded that Lodgepole Pine 

 is perhaps of all important trees in the country, the most prolific 

 seeder, and reproduces especially abundantly on burned areas. 

 Whether Lodgepole Pine grows upon this particular class of soil 

 as a result of the peculiar physical composition of the soil or 

 because of its chemical constituents as a result of the fire is not 

 known, but the important fact is that on burned areas a dense 

 reproduction of from 45,000 to 150,000 per acre is commonly se- 

 cured. On a few plots of reproduction taken in the open, young 

 growth up to 20 feet in height was found to contain about 60,000 

 trees to the acre. Under such conditions competition for light is 

 too keen, and as a result both height and diameter growth suffer. 



So much has been written about Lodgepole Pine reproduction 

 in the open that it does not seem necessary to supplement the in- 

 formation (See Forest Service Bulletin 79, 1910, etc.) by further 

 reference to this class of reproduction. Suffice it to say that re- 



