﻿TIMBER; 
  FORESTRY 
  

  

  115 
  

  

  109. 
  Propagation 
  of 
  trees 
  in 
  woodlands. 
  Many 
  kinds 
  of 
  

   forest 
  can 
  be 
  so 
  managed 
  that 
  the 
  young 
  trees 
  sown 
  by 
  natural 
  

   agencies 
  suffice 
  to 
  keep 
  up 
  the 
  stand 
  when 
  the 
  largest 
  trees 
  are 
  

   felled 
  (fig. 
  97). 
  The 
  

   seeds 
  of 
  most 
  conifers 
  

   are 
  readily 
  carried 
  con- 
  

   siderable 
  distances 
  by 
  

   the 
  wind, 
  and 
  those 
  of 
  

   many 
  broad 
  -leaved 
  trees, 
  

   as 
  birches, 
  elms, 
  ashes, 
  

   maples, 
  and 
  others, 
  are 
  

   carried 
  in 
  the 
  same 
  

   way. 
  Squirrels 
  carry 
  

   many 
  nuts 
  and 
  acorns 
  

   and 
  often 
  bury 
  them 
  

   where 
  they 
  can 
  grow. 
  

   Many 
  birds 
  - 
  - 
  for 
  ex- 
  

   ample, 
  the 
  bluejays 
  - 
  

   carry 
  acorns, 
  and 
  most 
  

   fruit-eating 
  birds 
  dis- 
  

   seminate 
  such 
  seeds 
  as 
  

   those 
  of 
  the 
  red 
  cedars, 
  

   wild 
  cherries, 
  hack- 
  

   berry, 
  mulberry, 
  and 
  

   a 
  few 
  other 
  trees, 
  often 
  

   carrying 
  them 
  many 
  

   miles. 
  Tolerant 
  seed- 
  

   lings 
  may 
  establish 
  

   themselves 
  in 
  the 
  shade 
  

   of 
  full-grown 
  trees. 
  

  

  The 
  expense 
  of 
  plant- 
  

   ing 
  seeds 
  or 
  setting 
  out 
  

  

  young 
  trees 
  in 
  woodlands 
  is 
  usually 
  so 
  great 
  as 
  to 
  make 
  it 
  

   unprofitable, 
  since 
  the 
  natural 
  growth 
  will 
  renew 
  itself 
  with 
  

   a 
  little 
  artificial 
  aid. 
  It 
  is, 
  however, 
  important 
  to 
  clear 
  away 
  

   undershrubs 
  that 
  are 
  overshadowing 
  desirable 
  seedling 
  trees. 
  

  

  FIG. 
  96. 
  Part 
  of 
  a 
  windbreak 
  of 
  cottonwood, 
  

   ten 
  years 
  old 
  

  

  Trees 
  planted 
  5 
  ft. 
  x 
  6ft., 
  thinned 
  to 
  6ft. 
  x 
  10ft. 
  

   The 
  trunks 
  will 
  make 
  good 
  lumber, 
  as 
  the 
  lower 
  

   branches 
  will 
  all 
  be 
  killed 
  by 
  the 
  shade. 
  Photo- 
  

   graph 
  by 
  United 
  States 
  Forest 
  Service 
  

  

  