HEIGHT GROWTH. 55 



Next come : Beech, Scotch pine, oak, ash, lime, elm, Norway 

 maple, sycamore ; then poplar and birch. These species do 

 not, except under specially favom^able conditions, exceed a 

 height of 110 feet. 



Beech reaches in Normandy a height of 170 feet ; oak one of 

 150 feet, but these are exceptional heights. Douglas fir, if not 

 exposed to strong winds, is likely to reach a still greater height. 



Next come : Austrian pine, Cembran pine, hornbeam, alder, 

 willow. They do not, as a rule, exceed 75 feet in height. 



b. Age. 

 The energy of height growth during the first part of life is 

 of special importance in sylviculture. Generally, the light 

 demanding species are at this time faster growing than the 

 shade bearing species. Assuming favourable conditions of 

 growth as found in the natural home of each species, they 

 may during youth be arranged as follows, commencing with 

 the fastest growing kind : — 



Birch, larch. 

 Aspen, alder, Norway maple, sycamore, ash, lime, elm. 

 Douglas fir, Weymouth pine. 

 Scotch pine. 

 Austrian pine. 

 Sweet chestnut, oak. 

 Beech. 

 Hornbeam. 

 Spruce, Cembran pine. 

 Silver fir. 

 Yew. 

 As soon as the first youth, say up to 20 or 30 years, has been 

 passed, a considerable change occurs. Some species, like larch, 

 and under favourable circumstances also Douglas fir, Wey- 

 mouth pine, Scotch pine and birch, preserve their fast growth 

 until they have completed their principal height growth. 



Others, like Ceml:)ran pine and hornbeam, remain slow 

 height growers throughout life. The majority of species, 



