HOW BIG TREES GROW 49 



After forty years the mad race rather slows down. 

 The period of most rapid height growth has passed and 

 the three hundred or four hundred trees now forming 

 the stand, tall and rather slim with crowns completely 

 shading the ground are the picked survivors of the 

 10,000 that started and each, is nearly as strong as his 

 fellow. From now on they commence to take on girth 

 like boys who suddenly change from gangling youths 

 to sturdy young men. Good wide rings are laid around 

 the trunks, covering up the places where branches 

 formerly pushed through the bark. This means clear 

 timber free from knots and easy to work, the kind that 

 delights the carpenter or the pattern maker. 



From now on our forest community loses a citizen 

 from time to time, from lightning stroke, disease, in- 

 sects, etc. The holes in the canopy are soon filled by 

 the neighboring crowns which still possess the power 

 of vigorous growth. The trees are now reaching 

 maturity with tall cylindrical boles, having from fifty 

 to sixty feet of clear length since the crown has been 

 continually shortening. Finally a time comes when 

 the crowns can no longer fill the gaps and the opening 

 made by a fallen veteran remains open and permits the 

 sunlight to reach the ground beneath the trees. The 

 forest floor previously shaded and free from weeds now 

 shows patches of grass here and there, the thick layer 

 of humus begins to decompose under the influence of 

 sunlight and the forest as a whole is ready to reproduce 

 itself beneath its own shade. This period, known as 

 "silvicultural maturity," occurs some time before the 

 final breaking up of the old stand but nevertheless it 

 marks the beginning of the end. 



From now on the decline is quite rapid as measured in 

 forest periods. The groups of seedlings found beneath 



