RED ALDER OF THE PACIFIC NORTHWEST 
35 
Leaf-eating insects, especially caterpillars of various species, occa- 
sionally destroy the foliage of alder on considerable areas, but the 
only effect of this defoliation is to lessen the season's growth. Boring 
insects sometimes kill individual branches but rarely whole trees. 
REPRODUCTION AND DEVELOPMENT 
Seed production is moderately abundant, and judging by the readi- 
ness with which burns and cut-over areas become restocked with 
Fig. 11. 
-A TYPICAL STAND OF ALDER ABOUT 10 YEARS OLD, ON CUT-OVER 
LAND 
alder, the seed must scatter widely and germinate freely (fig. 11). 
The seedlings become established readily either on litter or on min- 
eral soil, in partial shade, or in the open. Root sprouts are common, 
and stump sprouts are not unusual, yet neither can be relied on 
to stock burned or cut-over areas. 
