356 JOURNAL OF FORESTRY 



become an important factor in the cutting method ? Is it possible that 

 it will appreciably shorten the rotation? 



4. What is the effect of fire on cut-over stands? If clear cutting 

 is practiced, where there is adequate advance reproduction and a 

 severe fire later destroys all this reproduction, will the scattered little 

 bull pines which may survive be sufficient to restock the ground ? 



The field work of the study was carried on almost entirely on old 

 cut-over areas in and about the Whitman and Minam National. Forests. 

 The cut-over forest, and not the virgin forest, was studied, because, 

 obviously, the factors which affect the managed forest are those pre- 

 vailing chiefly under cut-over conditions. Fourteen separate cut-over 

 areas, ranging from 5 to 50 years old, were visited in the course of the 

 field work. On these areas sample acres were laid out in stands where 

 different percentages by volume were left standing from 8 to 53 per 

 cent. Altogether 24 sample plots were taken, and on them the radial 

 growth for the last 60 to 100 years was gotten from 400 trees by using 

 an increment borer. Reproduction was principally studied by running 

 arbitrary lines 10 and 20 chains across cuttings and taking square rods 

 every chain, on which all the seedlings were tallied by age and height. 

 In this way the reproduction on 99 square rod quadrates was examined. 

 Windfall was investigated on 15 and 20 year old cuttings by taking 

 large sample areas, 20 and 40 acres in size, and classifying all the 

 thrown trees by diameter, height, and the year after cutting when 

 thrown. In determining the effects of fire, five private burned-over 

 cuttings, from 30 acres to 400 acres in extent, were studied, and in a 

 timber sale cutting a 40-acre area on which the brush was burned in 

 piles was examined. 



From a correlation of the data collected in the field the following 

 results were obtained: 



With regard to accelerated growth 



1. The trees left standing in a selection cutting experienced a very 

 pronounced accelerated growth, which takes place from 100 to 300 per 

 cent faster than the growth before cutting, and which continues for 30 

 to 40 years following cutting. 



2. The rate of accelerated growth bears an inverse relation to the 

 per cent by volume of the trees reserved ; where 10 per cent is reserved 

 the increased growth is 290 per cent faster than the growth before 

 cutting, and where 50 per cent is reserved it is only 75 per cent faster. 



3. Accelerated growth is best secured where the reserved trees are 



