PREPARATORY FELLINUS IN THE UNIFORM METHOD. 333 



none at all may be necessary ; but usually the number of these 

 will vary from two to four, repeated at intervals of from 4 to 6 

 years. 



III. When to begin the preparatory fellings. 



The time to begin the preparatory fellings will depend on the 

 number of such fellings to be made, combined with the following 

 considerations : 



(i) The component species. Different species grow up with 

 different degrees of rapidity, reach different statures which they 

 attain at different ages, enjoy different terms of longevity, become 

 fertile at different ages, require different degrees of insolation and 

 different periods of release from an overcrowded state in order to 

 acquire a sufficient spread of crown to come into full bearing, and 

 so on. Thus trees, which attain the best marketable dimensions at 

 an early age, or which become fully fertile late, or which naturally 

 grow crowded together, and so on, require to be prepared from an 

 early age. 



In a mixed forest, the time for the commencement of the fellings 

 will be determined entirely by the exigencies of the principal 

 species, and if there are more than one such species, by the 

 exigencies of that one among them, which becomes fertile last of 

 all, or which, being the slowest grower or the most shade-avoiding, 

 requires to be given a start over its fellows (see pp. 128, II and 

 III). 



(ii) The soil, influencing, as it must, the rapidity and vigour 

 of growth of the trees, their longevity, their bearing age, their 

 habit, their requirements in respect of light, and their fruitfulness 

 and the quality of their seed at different ages. For instance, in 

 favourable soils, in which the trees will be naturally vigorously 

 developed, the commencement of the preparatory fellings will 

 generally be delayed. The condition of the soil as a seed-bed will 

 also be an important factor for consideration. Its suitability in 

 this respect will depend not only on its inherent properties, such 

 as its stiffness, hardness, hygroscopicity, richness, &c., but also, in 

 a very great measure, on the condition of its surface. The stiffer 

 or harder or drier or poorer the soil, the thicker the undecomposed 

 layer of dead leaves covering it, or the denser the growth of weeds 

 and bruslrvvood on it, the longer will it take to get ready for sowing 

 and the earlier must the preparation be begun. 



(iii) The climate and locality. In hot sunny localities the 

 leaf-canopy is generally naturally open and the trees are seldom so 



