﻿up 
  the 
  slope, 
  under 
  more 
  cool 
  and 
  more 
  moist 
  

   conditions, 
  other 
  species 
  begin 
  to 
  appear. 
  As 
  

   elevation 
  increases, 
  ponderosa 
  pine 
  is 
  no 
  long- 
  

   er 
  present; 
  then 
  other 
  species 
  disappear 
  while 
  

   new 
  ones 
  appear. 
  This 
  process 
  continues 
  up 
  

   to 
  the 
  timberline. 
  

  

  The 
  diagram 
  is 
  a 
  simplification, 
  and 
  shows 
  

   only 
  the 
  effects 
  of 
  changes 
  in 
  elevation 
  on 
  

   the 
  moisture-temperature 
  regimes 
  of 
  the 
  habi- 
  

   tat 
  situation. 
  Other 
  site 
  features, 
  such 
  as 
  

   topography, 
  aspect, 
  vegetative 
  cover, 
  and, 
  soil 
  

   characteristics, 
  also 
  affect 
  the 
  habitat 
  condi- 
  

   tion, 
  and 
  thus 
  the 
  range 
  of 
  individual 
  species. 
  

   For 
  example, 
  the 
  difference 
  between 
  south 
  

   and 
  north 
  slopes 
  can 
  have 
  an 
  effect 
  equiva- 
  

   lent 
  to 
  a 
  difference 
  in 
  elevation. 
  The 
  com- 
  

   bined 
  features 
  of 
  the 
  environment 
  provide 
  

   some 
  habitat 
  condition 
  to 
  which 
  each 
  species 
  

   is 
  adapted 
  to 
  some 
  degree. 
  

  

  Also 
  shown 
  relatively 
  in 
  figure 
  1 
  is 
  the 
  

   range 
  of 
  conditions 
  under 
  which 
  a 
  species 
  

   occurs 
  as 
  a 
  climax 
  species; 
  that 
  is, 
  the 
  range 
  

   in 
  which 
  it 
  can 
  perpetuate 
  itself 
  in 
  competi- 
  

   tion 
  with 
  other 
  species 
  native 
  to 
  the 
  site. 
  The 
  

   crosshatching 
  on 
  each 
  species 
  bar 
  shows 
  the 
  

  

  extent 
  to 
  which 
  that 
  species 
  is 
  climax. 
  White 
  

   pine, 
  larch, 
  lodgepole 
  pine, 
  and 
  Engelmann 
  

   spruce 
  are 
  strictly 
  successional 
  species. 
  1 
  The 
  

   other 
  species 
  can 
  become 
  climax 
  in 
  certain 
  

   situations 
  and 
  over 
  sufficient 
  length 
  of 
  time. 
  

   However, 
  the 
  important 
  timber 
  species 
  are 
  ser- 
  

   ai 
  over 
  most 
  of 
  their 
  natural 
  range 
  (table 
  1). 
  

  

  Factors 
  of 
  Risk 
  

  

  The 
  species 
  that 
  can 
  be 
  grown 
  on 
  white 
  

   pine 
  lands 
  may 
  be 
  determined 
  from 
  the 
  chart 
  

   (fig. 
  1) 
  and 
  table 
  1. 
  For 
  some 
  of 
  these 
  species, 
  

   however, 
  the 
  element 
  of 
  risk 
  may 
  be 
  great 
  

   enough 
  to 
  eliminate 
  the 
  species 
  from 
  con- 
  

   sideration. 
  A 
  degree 
  of 
  risk 
  in 
  growing 
  any 
  

   species 
  is 
  a 
  biological 
  fact 
  of 
  life 
  in 
  forestry, 
  

   but 
  risk 
  varies 
  widely. 
  Volume 
  losses 
  from 
  

  

  ^Engelmann 
  spruce 
  may 
  become 
  climax, 
  but 
  only 
  

   in 
  the 
  Engelmann 
  spruce-subalpine 
  fir-grouse 
  

   whortleberry 
  (huckleberry) 
  habitat 
  type, 
  which 
  

   Daubenmire 
  feels 
  is 
  uncommon 
  and 
  peripheral 
  in 
  

   the 
  Northern 
  Region, 
  since 
  he 
  found 
  only 
  four 
  iso- 
  

   lated 
  occurrences 
  in 
  northeast 
  Washington 
  and 
  north 
  

   Idaho. 
  (R. 
  Daubenmire. 
  Vegetation: 
  Identification 
  

   of 
  typal 
  communities. 
  Science 
  151 
  (3708): 
  291-298. 
  

   1966.) 
  

  

  Table 
  1 
  .- 
  

  

  -The 
  distribution 
  and 
  ecological 
  role 
  

  

  of 
  the 
  

  

  major 
  species 
  

  

  

  

  

  by 
  important 
  tree 
  union 
  1 
  

  

  

  

  

  ( 
  Key: 
  

  

  s, 
  minor 
  sera! 
  role; 
  S, 
  major 
  

  

  serai 
  role; 
  c, 
  

  

  minor 
  c 
  

  

  limax 
  role; 
  

  

  

  

  

  C, 
  major 
  climax 
  role.) 
  

  

  

  

  

  Major 
  

   Species 
  

  

  

  

  Climax 
  tree 
  union 
  

  

  

  

  Ponderosa 
  

   pine 
  

  

  Douglas- 
  

   fir 
  

  

  Grand 
  

   fir 
  

  

  Spruce- 
  

   fir 
  

  

  Cedar 
  

  

  Hemlock 
  

  

  White 
  pine 
  

  

  

  

  s 
  

  

  S 
  

  

  S 
  

  

  S 
  

  

  Subalpine 
  fir 
  

  

  

  

  

  c 
  

  

  

  s 
  

  

  Engelmann 
  spruce 
  

  

  

  

  

  S,c 
  

  

  

  s 
  

  

  Western 
  hemlock 
  

  

  

  

  

  

  

  C 
  

  

  Mountain 
  hemlock 
  

  

  

  

  

  

  

  C 
  

  

  Western 
  redcedar 
  

  

  

  

  

  

  C 
  

  

  s 
  

  

  Whitebark 
  pine 
  

  

  

  

  

  s 
  

  

  

  

  Lodgepole 
  pine 
  

  

  

  S 
  

  

  S 
  

  

  s 
  

  

  S 
  

  

  s 
  

  

  Grand 
  fir 
  

  

  

  

  C 
  

  

  s 
  

  

  S 
  

  

  s 
  

  

  Western 
  larch 
  

  

  

  S,s 
  

  

  S 
  

  

  S,s 
  

  

  s 
  

  

  s 
  

  

  Douglas-fir 
  

  

  

  C 
  

  

  s 
  

  

  S,s 
  

  

  s 
  

  

  s 
  

  

  Ponderosa 
  pine 
  

  

  C 
  

  

  S 
  

  

  s 
  

  

  

  s 
  

  

  s 
  

  

  1 
  Adapted 
  from 
  Daubenmire, 
  R. 
  F., 
  Classification 
  of 
  conifer 
  forests 
  in 
  eastern 
  Washington 
  and 
  north- 
  

   ern 
  Idaho. 
  Northwest 
  Sci. 
  27:17-24, 
  1953. 
  

  

  4 
  

  

  