﻿TIMBKR 
  YIELD*. 
  

  

  41 
  

  

  upon 
  which 
  this 
  table 
  is 
  based, 
  were 
  carefully 
  made, 
  and 
  it 
  is 
  believed 
  

   the 
  table 
  is 
  a 
  fair 
  estimate 
  of 
  what 
  may 
  be 
  expected. 
  It 
  is 
  exceed- 
  

   ingly 
  probable 
  that 
  it 
  underestimates 
  rather 
  than 
  overestimates, 
  since 
  

   not 
  only 
  were 
  the 
  most 
  conservative 
  figures 
  used 
  throughout, 
  but 
  no 
  

   allowance 
  has 
  been 
  made 
  for 
  the 
  improved 
  conditions 
  for 
  forest 
  growth 
  

   which 
  will 
  result 
  under 
  the 
  application 
  of 
  conservative 
  lumbering. 
  

  

  The 
  table 
  also 
  shows 
  the 
  yield 
  per 
  acre 
  of 
  merchantable 
  pine 
  which 
  

   may 
  be 
  expected 
  after 
  twenty, 
  thirty, 
  and 
  forty 
  years, 
  cutting 
  to 
  the 
  

   diameter 
  limits 
  of 
  12. 
  14. 
  16. 
  18, 
  and 
  20 
  inches 
  breasthigh. 
  and 
  also 
  

   the 
  time 
  required 
  before 
  a 
  yield 
  equal 
  to 
  the 
  present 
  merchantable 
  

   stand 
  may 
  again 
  be 
  obtained. 
  

  

  Table 
  No. 
  12. 
  — 
  Present 
  and 
  future 
  yields 
  of 
  pine 
  per 
  acre, 
  and 
  time 
  necessary 
  before 
  the 
  

   present 
  yield 
  may 
  again 
  be 
  obtained. 
  

  

  Cutting- 
  

   limit, 
  

   diameter 
  

   breasthigh. 
  

  

  Present 
  

   cut. 
  

  

  Cut 
  after 
  

   20 
  years. 
  

  

  Cut 
  after 
  

   30 
  years. 
  

  

  Cut 
  after 
  

   40 
  years. 
  

  

  Present 
  

   cut 
  again 
  

   obtained. 
  

  

  Inches. 
  

  

  Board 
  feet. 
  

  

  Board 
  feet. 
  

  

  Board 
  feet. 
  

  

  Board 
  feet. 
  

  

  Years. 
  

  

  12 
  

  

  6.067 
  

  

  1,047 
  

  

  2,467 
  

  

  5,270 
  

  

  42 
  

  

  14 
  

  

  5,845 
  

  

  957 
  

  

  2,40S 
  

  

  5,278 
  

  

  41 
  

  

  16 
  

  

  5,597 
  

  

  1.225 
  

  

  2,678 
  

  

  5,212 
  

  

  41 
  

  

  18 
  

  

  5, 
  130 
  

  

  1.309 
  

  

  2,612 
  

  

  4. 
  678 
  

  

  42 
  

  

  20 
  

  

  4,561 
  

  

  1,381 
  

  

  2,333 
  

  

  4, 
  174 
  

  

  42 
  

  

  It 
  will 
  be 
  noticed 
  that 
  in 
  general 
  the 
  cut 
  after 
  twenty 
  years 
  increases 
  

   as 
  the 
  diameter 
  limit 
  is 
  raised: 
  that 
  at 
  thirty 
  years 
  the 
  cut 
  increases 
  

   to 
  the 
  10-inch 
  limit, 
  and 
  then 
  falls 
  away 
  again, 
  and 
  that 
  at 
  forty 
  years 
  

   it 
  decreases 
  as 
  the 
  diameter 
  limit 
  increases. 
  

  

  The 
  time 
  required 
  before 
  equal 
  cuts 
  can 
  again 
  be 
  obtained 
  is 
  irregular 
  

   and 
  needs 
  explanation. 
  Ordinarily, 
  raising 
  the 
  diameter 
  limit 
  decreases 
  

   the 
  time. 
  But 
  the 
  table 
  shows 
  that 
  the 
  time 
  is 
  here 
  the 
  same 
  whether 
  

   the 
  diameter 
  limit 
  is 
  12 
  or 
  20 
  inches 
  — 
  forty-two 
  years 
  in 
  each 
  case. 
  

   This 
  is 
  due 
  partly 
  to 
  the 
  fact 
  that 
  the 
  growth 
  of 
  the 
  pine 
  of 
  small 
  

   diameters, 
  especially 
  that 
  of 
  the 
  Loblolly. 
  La 
  very 
  rapid. 
  In 
  forty- 
  

   two 
  years 
  Loblolly, 
  with 
  a 
  present 
  diameter 
  of 
  12 
  inches, 
  and 
  Short- 
  

   leaf, 
  with 
  a 
  present 
  diameter 
  of 
  14 
  inches, 
  will 
  have 
  passed 
  the 
  2<>-inch 
  

   limit, 
  and 
  Loblolly 
  of 
  2 
  inches 
  and 
  Shortleaf 
  of 
  5 
  inches 
  will 
  have 
  

   passed 
  the 
  12-inch 
  limit. 
  A 
  second 
  reason 
  for 
  the 
  disproportionate 
  

   length 
  of 
  the 
  period 
  required 
  to 
  produce 
  a 
  second 
  crop 
  equal 
  to 
  the 
  

   first 
  at 
  a 
  20-inch 
  diameter 
  limit 
  is 
  the 
  fact 
  that 
  the 
  forest 
  is 
  i- 
  abnormal." 
  

   the 
  number 
  of 
  trees 
  between 
  14 
  and 
  20 
  inches 
  being 
  especially 
  small, 
  

   as 
  is 
  shown 
  by 
  tig. 
  1, 
  the 
  probable 
  result 
  of 
  the 
  severer 
  tires 
  due 
  to 
  

   the 
  accumulated 
  rubbish 
  when 
  tires 
  first 
  became 
  frequent. 
  These 
  are 
  

   just 
  the 
  trees 
  which 
  would 
  have 
  to 
  furnish 
  the 
  next 
  equal 
  crop 
  cutting 
  

   to 
  a 
  diameter 
  limit 
  of 
  20 
  inches. 
  

  

  