214 BRITISH FOREST TREES 



forest trees ; it demands entire freedom of crown, even on 

 the soils and situations which suit it best. It therefore 

 shuns the coombs and dingles, and avoids the bends and 

 hollows of hilly land, preferring the insolation of open 

 plains or of warm southern and western exposures. In 

 mixed forest it is to be found in companionship with other 

 light-loving species, Scots pine, aspen, oak, alder, &c., 

 rather than with the densely-foliaged beech, silver fir, or 

 spruce, which evidently keep the soil too cool for its require- 

 ments. The growing-space required for the crown is con- 

 siderable, as the birch brooks no interference or competi- 

 tion even from the lightly foliaged crowns of its own 

 species. 



Attainment of Maturity and Reproductive Capacity. 

 The birch begins to bear seed as early as the twenty-fifth to 

 thirtieth year, though not infrequently even so soon as the 

 fifteenth to twentieth where the crown has free develop- 

 ment, and produces it nearly every year, ripening in 

 September, or on sandy soils often in August. It has a 

 very small germinative capacity, and 20 to 25 per cent, are 

 reckoned a good result in experiments for testing the 

 quality of the seed. There are about 800,000 to 900,000 

 seeds in one pound. As might almost be expected from 

 its enormous seed-production, the power of regenerating 

 itself from the stool is somewhat limited and capricious, 

 though varying w r ith the nature of the soil and situation. 



Wherever it is desirable to restrict the number of self- 

 sown seedlings at the time of natural reproduction of 

 other species, the birch must be cut out early from mixed 

 forests ; but where there is little danger of the seedlings 

 interfering with the regenerated growth, as for instance in 

 copse or stored coppice, the birch is well adapted for being 

 held over as a standard, and allowed to develop into a 

 fair-sized stem. In general its sylvicultural maturity is 



