ECONOMIC VALUE OF FOREST FLORA 193 



4. Rapid rate of growth on comparatively poor soil. 



5. High quality or specific value of timber. 



It will perhaps be difficult to find any one species 

 possessing all the above characteristics, but it is obvious 

 that no species can be termed profitable which does not 

 exhibit two or three of them. 



1. Plentiful seed production is an important feature in 

 any species, but is especially desirable in one which 

 requires to be grown on a large scale to create a market 

 for its timber. With scanty or irregular seed supplies 

 the cost of young plants increases, and may even be 

 prohibitive. Many introductions from North America, 

 Japan, etc., might be profitably grown in this country 

 were it not for the cost and trouble of collecting their 

 seed. Douglas fir, Japanese larch, Abies grandis, etc., 

 are instances of species which occasionally fail to produce 

 crops, while Pinus monticola, Larix occidentalis, and 

 others are almost impossible to obtain on account of 

 scarcity of seed. It is evident that no species can be 

 cheaply and extensively planted which cannot be 

 obtained in public nurseries, at a size fit to plant out, for 

 from 20s. to 40s. per 1000 — as, allowing for failures and 

 subsequent replacements, at least 1000 plants per 

 acre must be planted, exclusive of nurses, if a satisfactory 

 crop of any one species is to be obtained. With a plant 

 bill of more than £4 per acre, a species must be a very 

 rapid grower, therefore, to show a satisfactory return at 

 the end of sixty or eighty years, and it is only occa- 

 sionally that one is found to do what is required. 



The surest and heaviest seed producers in Britain at 

 intervals of three to five years are Scots pine, wych elm, 

 sycamore, ash, beech, oak, birch, and alder. Amongst 

 other species hardy in Britain, larch, spruce, silver fir, 

 Abies nobilis, Douglas fir, Corsican and Austrian pines, 

 maritime and Weymouth pines, all produce moderate 



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