BRITISH FOREST TREES 



It appears, therefore, from the carefully compiled tables 

 from which the above abstract is made, that, on soils of the 

 best quality usually found under forest, the current annual 

 increase in height is : 



Has already decreased to below 



Forest of 



Attains its maximum 

 during 



Half of its maximum . Quarter of its maximum 

 during during 



On soils of inferior quality the current annual increase in 

 height follows much the same curve, but usually takes some- 

 what longer to culminate. The years of culmination shown 

 by these tables are approximately as follows : 



The absolute average height of the trees forming the forest 

 varies very considerably, however, according to the quality of 

 the soil, as may be seen from the table on page 38 (in feet). 

 Thus on poor soil the Scots pine at eighty years' growth 

 has not attained the same average height as is reached on the 

 best class of pine soil after forty years' growth ; up till about 

 the fiftieth year it is of quicker growth than the other species, 

 but is then overtopped by the spruce and silver fir, whilst 

 it is hardly at any later period dominated by the beech- 



