356 NOTES ON BRITISH FOREST TREES. 



One pound of seed contains about 10.000 clean ^^ni'mi^ with- 

 out wings. 



Direct sowings may l)e made in si)ring or autmnn. tlie latter 

 season being on the whole preferable, as the seed is diilicult 

 to keep. If spring sowings are decided on, the seed must be 

 kept in an airy loft and occasionally turned. Spring sowings 

 sprout after three to five weeks. About -10 pounds of seed per 

 acre are required for l)roadcast sowings ; it receives a cover of 

 about two-thirds of an inch. Sowings in patches under the 

 shelter of existing woods are more frequent than broadcast 

 sowings. 



In nurseries the seed may be sown in drills, or broadcast : 

 the seedlings should remain for two years in the seed l)ed, and 

 two years and upwards in nursery linos. In Kngland they 

 are rarely put out under live years old; the })lants may be 

 placed :-3 to 4 feet apart. The young plants generally retjuire 

 protection against frost and drought. 



The silver iir is best regenerated naturally under a shelter- 

 wood, the selection and group system being perhaps even 

 better suited to it than the compartment system. The process 

 of regeneration is a slow one. In most mature silver fir woods 

 groups of advance growth are found, where operations may be 

 commenced. By removing the shelter trees standing over 

 such advance growth, and gradually the adjoining trees, 

 regeneration extends all round, and the groups expand until 

 they ultimately merge into each other. In this way the 

 regeneration period of a wood may extend over 30, 40, and 

 even 50 years. The old trees, being gradually placed into an 

 open position, increase rapidly in diameter, volume and value. 

 At the same time they should be removed when the young 

 crop demands it. 



/. Tc/u/in;/. 



FcriHitij oj Soil. — Silver lir, if treated i)roperly, is an 

 excellent preserver of the fertility of the soil. 



Kxtcnial J)(ui'j(rn. — The young trees requije shelter against 



