﻿Some 
  applications 
  of 
  the 
  quadrat 
  method 
  

  

  Henry 
  Allan 
  Gleason 
  

  

  By 
  the 
  quadrat 
  method 
  in 
  ecological 
  phytogeography 
  is 
  meant 
  

   the 
  intensive 
  study 
  of 
  the 
  vegetation 
  or 
  environment 
  of 
  a 
  limited 
  

   and 
  definitely 
  circumscribed 
  area, 
  known 
  as 
  a 
  quadrat, 
  in 
  order 
  

   to 
  gain 
  a 
  comprehensive 
  knowledge 
  of 
  the 
  vegetation 
  as 
  a 
  whole. 
  

   The 
  development 
  of 
  the 
  method 
  is 
  the 
  direct 
  outgrowth 
  of 
  a 
  need 
  

   which 
  has 
  been 
  felt 
  by 
  every 
  ecologist 
  who 
  has 
  seriously 
  attempted 
  

   the 
  study 
  of 
  vegetational 
  units. 
  While 
  its 
  use 
  is 
  of 
  great 
  value 
  

   and 
  leads 
  frequently 
  to 
  generalizations 
  which 
  would 
  otherwise 
  be 
  

   difficult 
  or 
  impossible, 
  it 
  is 
  not 
  complete 
  in 
  itself, 
  and 
  ecologists 
  

   are 
  unable 
  to 
  rely 
  upon 
  it 
  alone 
  as 
  a 
  means 
  toward 
  successful 
  

   field 
  work. 
  Indeed, 
  its 
  use 
  to 
  the 
  exclusion 
  of 
  all 
  other 
  methods 
  

   has 
  never 
  been 
  suggested. 
  It 
  does 
  constitute, 
  however, 
  the 
  only 
  

   practicable 
  means 
  for 
  the 
  quantitative 
  study 
  of 
  the 
  association, 
  

   and 
  as 
  such 
  it 
  forms 
  an 
  important 
  adjunct 
  to 
  photography 
  and 
  

   verbal 
  description, 
  which 
  were 
  previously 
  the 
  only 
  feasible 
  means 
  

   of 
  presenting 
  the 
  structure 
  of 
  vegetation. 
  It 
  also 
  plays 
  an 
  im- 
  

   portant 
  part 
  in 
  the 
  study 
  of 
  associational 
  dynamics, 
  as 
  migration 
  

   and 
  succession, 
  and 
  environometry. 
  

  

  It 
  IS 
  exceedingly 
  difficult 
  and 
  in 
  many 
  cases 
  impossible 
  for 
  a 
  

   reader 
  to 
  form 
  a 
  clear 
  mental 
  picture 
  of 
  an 
  association 
  from 
  a 
  

   written 
  description, 
  as 
  may 
  be 
  demonstrated 
  by 
  a 
  perusal 
  of 
  any 
  

   discussion 
  of 
  an 
  otherwise 
  unfamiliar 
  type 
  of 
  vegetation. 
  The 
  

   value 
  of 
  a 
  verbal 
  description 
  is 
  always 
  greatly 
  enhanced 
  by 
  photog- 
  

   raphy. 
  There 
  are 
  certain 
  physical 
  limitations 
  to 
  the 
  value 
  of 
  a 
  

   general 
  photograph, 
  caused 
  by 
  the 
  difficulties 
  of 
  field 
  photography 
  

   and 
  the 
  necessity 
  of 
  reducing 
  the 
  print 
  to 
  the 
  usual 
  compass 
  of 
  a 
  

   page, 
  so 
  that 
  a 
  general 
  view 
  of 
  an 
  association 
  seldom 
  gives 
  a 
  

   sufficiently 
  clear 
  idea 
  of 
  the 
  vegetation, 
  since 
  the 
  component 
  

   species 
  are 
  distinguishable 
  only 
  In 
  the 
  Immediate 
  foreground, 
  if 
  at 
  

   all. 
  A 
  detailed 
  photograph 
  of 
  a 
  small 
  part 
  of 
  the 
  association, 
  on 
  

   the 
  other 
  hand, 
  is 
  frequently 
  made 
  with 
  difficulty 
  and 
  It 
  is 
  often 
  

   impossible 
  to 
  choose 
  for 
  illustration 
  an 
  Isolated 
  portion 
  which 
  is 
  

  

  21 
  

  

  