TKEES FOE WATER CATCHMENT AREAS 143 



feeble growth on dry soils, and was killed outright in dry 

 situations generally by the great drought of 1911. 



One main use of Japanese larch in this country is to 

 produce a crop of pit timber in a short term of years, say 

 in 20 to 25 years after planting. Owing to its great 

 vigour at the start it can also be used for planting difficult 

 sites where other species fail, as, for example, land liable 

 to be covered with a matted dense growth of grass, such as 

 occurs in districts lying on the western seaboard of Scotland 

 and in many parts of Ireland. It will succeed on poor 

 shallow soil (Fig. 24) provided there is sufficient moisture. It 

 has been recommended for planting areas overrun with furze 

 and bracken ; but such land if not in too exposed a situation 

 will, as a rule, support other species yielding better timber. 



Japanese larch may be used as a main-crop tree in 

 localities where pitwood is readily saleable ; and is, of 

 course, a substitute for European larch in parts of the 

 country where the latter suffers severely from canker. 

 It may be looked upon as a catch-crop tree, to be planted 

 with the idea of getting a speedy return from an area 

 difficult to afforest. Land on which Japanese larch had 

 been grown for a short rotation of 20 to 30 years would 

 be in excellent condition for the planting of another species 

 destined for growing valuable timber on a long rotation. 



The growth of Japanese larch seems to be little affected 

 by the nature of the soil, provided it contains sufficient 

 moisture. The growth in height, while extremely rapid in 

 youth, later drops off very considerably. The average 

 attained by plantations in this country is about 32 feet 

 at 16 years old from seed, 55 feet at 32 years old, and 

 65 feet at 37 years old. In young plantations the volume 

 comprises much branch wood of little value. The average 

 annual increment of plantations 32 years old may be reckoned 

 at 100 to 120 cubic feet of timber per acre. 



Western Larch {Larix occidentalis). — This is the finest 

 of all the larches, attaining in Western Montana and the 

 adjacent districts of Idaho (Fig. 23) and British Columbia 



