4 8 



BRITISH FOREST TREES 



worthy of note that the former, including birch, aspen, 

 willows, Scots pine, and spruce, make more moderate de- 

 mands as to soil and situation than the species with heavy 

 seeds such as oak, beech, silver fir, maple, and sycamore. 

 With their seed wafted to considerable distances by the 

 wind, and easily satisfied as to soil and situation, they must 

 be acknowledged to possess a considerably greater repro- 

 ductive capacity than species with heavy seeds. In many 

 parts of the Continent it may be observed how the domain 

 of oak and beech is gradually being invaded by the Scots 

 pine and the spruce, whilst in other localities these latter 

 have themselves to maintain a struggle against the en- 

 croachments of the still more easily satisfied birch, aspen, 

 and willow. 



The germinative capacity of the different kinds of seed 

 varies greatly. Ney gives the following as satisfactory 

 percentages in experiments for testing the quality of 

 deliveries by seedsmen (op. cit. p. 52). 



Birch ....10 Larch. ...35 ! Hornbeam 



50 



Alder ...15 



Elm 20 



Weymouth Silver fir. 50 

 pine ...50 



Ash 50 Maples ..50 



The seed of most species germinates in the spring after it 

 is shed, but that of birch, elm, aspen, and willows germinates 

 in the spring in which it falls, and that of ash and 

 hornbeam only in the second spring after its fall if it has 

 been stored. 



The Age of the Trees at which seed is produced in greatest 

 quantity is generally that at which, having just completed the 

 period when growth in height is most active, the individual 

 tree begins to develop its crown, and to display greatest 



