Some Permanent Sample Plot Studies 



119 



crown competition often determines the density. The forest 

 is an old uneven^aged stand composed chiefly of overmature 

 and mature trees with a very few of the younger age classes. 

 The mean annual growth for the type has been estimated to 

 be 50 board feet per acre. 



Reproduction along the higher portion of the timber sale 

 area is exceptionally good, where it is distributed locally in 

 patches. A dense growth of underbrush which occurs just 

 above the area would be encouraged to take possession of the 

 ground if cutting were too heavy. Three permanent sample 

 plots, each two chains square, laid out for a reproduction 

 study gave the following counts: 



TABLE 2. 



These figures show that of the entire reproduction on 

 the plots an average of only 4.7 per cent is Jeffrey Pine. In 

 this respect the area is not typical of the type for in pure 

 stands of Jeffrey Pine the reproduction averages eighty per 

 cent Jeffrey Pine and twenty per cent White Fir while in a 

 mixed stand such as the one which is being considered the 

 reproduction runs 60 per cent White Fir and 40 per cent 

 Jeffrey Pine.. This gross abnormality was considered when 

 choosing this sale area because of the opportunity to observe 

 the behavior of reproduction in culled stands which have a 

 high proportion of White Fir. 



A permanent sample plot containing twenty acres was 

 laid out on the above-mentioned Government timber sale area. 

 The plot was laid out at right angles to the contours so that 

 average conditions would be obtained. A standard compass 

 was used to get the alignment and the distance was chained. 

 After the entire distance around the plot has been covered 

 and the error of closure found, the courses and distances were 

 checked and the slight error of closure was uniformly distri- 

 buted. The second time around the plot every two-chain 

 point on the perimeter was marked by a small temporary stake 



