BRITISH FOREST TREES 133 



covering, but in localities where seed-production is some- 

 what deficient, and where there is probability of early germina- 

 tion and consequent danger from late frosts, it is advisable 

 to go over the strips with iron rakes after the seed has fallen, 

 unless the soil has been previously broken into clods with 

 the hoe. 



Where the wishes of the proprietor lead to the formation 

 of forests in which the annual or periodic fall is to consist of 

 timber of about equal age, there exists less necessity than 

 in the case of the spruce for dividing the total area under 

 silver fir into separate independent blocks, each having its 

 self-contained growing-stock of all ages from one year, or the 

 mean age of the first period, up to maturity, or the mean 

 age of the last period. The rate at which the clearance of 

 the standard trees takes place after natural reproduction 

 has been satisfactorily carried out, depends to a great extent 

 on local circumstances ; in some places it is gradually per- 

 formed by the annual removal of a portion, in other places a 

 heavier fall takes place only every four or five years. Most 

 anxiety is caused on moist soil where there is no proper 

 covering of moss, but a strong growth of grass instead, or 

 again on dry slopes with southern exposure. On good fresh 

 soil the retention of the standards in greater numbers does 

 not permanently injure the seedling crop, but on dry 

 situations deficient in soil-moisture a speedier clearance 

 must take place in order to let the young growth have the 

 full benefit of dew-fall, without which any considerable degree 

 of overshadowing might soon permanently damage the 

 weakly crop, or materially prejudice its ultimate recuperative 

 power after removal of the standards. On dry soils the 

 total clearance can hardly be delayed more than eight to 

 ten years after the seed-felling, and in some cases it is 

 advisable to complete it as early as the fifth or sixth year. 



In addition to considerations as to the direction of .ic 



