200 



FURESTKY IN THE UNITED KINGDOM. 



in the former country. Investigations have been going on 

 now for a considerable number of years, so that we have data 

 based upon many thousands of measurements. The author 

 has compared them with measurements made by him in this 

 country, and he is of opinion that, on average land, the 

 following are the most suitable numbers of trees at various 

 ages, whenever the production of clean timber is aimed at. 



Number of Trees per Acre. 



The numbers in the above table refer only to soil of 

 average quality. On first class soil the numbers are smaller, 

 and on inferior soil larger. Figures for larch are not avail- 

 able at present, as, owing to the larch disease, that species is 

 in Germany nowadays grown only in mixture with other 

 species, especially beech. In the meantime, the figures given 

 for Scotch pine apply, approximately, also to larch. 



The appended five pictures will illustrate the proper density 

 of woods grown for economic purposes. 



The matter, then, stands thus : We require at the age of 

 forty years the above-mentioned numbers of clean stems, and 

 the question is, how many plants should be put in to produce 

 them and at the same time shelter the ground sufficiently. 

 Here several matters must be considered. S})ruce, though at 

 first somewhat slow, does not develop very strong side 

 branches, while the early thinnings are practically of no 

 value, except where Christmas trees are saleable ; hence 

 2,700 plants (4 ft. X 4 ft.) are sufficient to produce 1,100 



