Previous Forest Protection in Canada 1913-1914 Next

 

218   COMMISSION OF CONSERVATION

The table below gives the average density per acre of Douglas Fir

Predominant   the young   g   grouped

Predominan   Dou Douglas fir forests   into age classes

of ten-year intervals. The actual age of these stands will be found under the section upon the influence of fires on forest reproduction.

TABLE I

NUMBER OP YOUNG TREES PER ACRE, ACCORDING TO AGE BY DECADES, BASED UPON
32 AcREs oP SAMPLE STRIPS

Age, by decades

Douglas

fir

Hemlock

Cedar

Balsam

White

pine

Total

trees

Less than 10 years    

53,300

1,000

3,300

..

..

57,600

LO to 20 years    

3,900

270

470

30

5

4,67C

?0 to 30 years    

1,100

220

170

20

5

1,51C

30 to 40 years    

410

270   100

10

..

79(

 

 

 

 

 

 

PERCENTAGES OF YOUNG TREES PER ACRE, ACCORDING TO DECADES, AS ABOVE

Age, by decades

Douglas

fir,

Hemlock,

Cedar,

Per cent

Balsam,

Per

White

Pine,

 

Per cent

Per cent

 

cent

per cent

Less than 10 years    

93.0

2.0

5.0

 

 

10 to 20 years    

83.4

5.7

10.0

0.7

0.1

20 to 30 years    

72.6

14.6

11.2

1.3

0.3

30 to 40 years    

52.0

34.0

12.6

1.3

 

 

 

 

 

 

 

One frequently finds small patches of fir in which the number of trees on an acre was much higher than given in the table above. For example, four-year-old stands sometimes ran as high as 322,000 little trees upon an acre, and even in the 16- and 18-year-old stands the number per acre frequently reached 30,000. The figures in the table, however, give a good idea of the general condition of the reproduction, including the poor as well as the good.

The table above clearly shows the natural thinning-out that takes place as the trees increase in age and size. In the case of the 57,600, less than 10 years old on an average acre, each little tree occupies less than a square foot of soil. If all of these trees lived until they were a foot in diameter, the result would be a solid block of wood upon an acre. We know that trees do not grow that way. There is not room enough for them all, so the weak die and the strong survive. As shown by the table, in this case 91 per cent of the trees had died by the end of the nineteenth year, 97 per cent at the end of 29 years, and 98 per cent


Previous Forest Protection in Canada 1913-1914 Next