﻿Gleason: 
  Some 
  applications 
  of 
  the 
  quadrat 
  method 
  25 
  

  

  quadrat 
  to 
  be 
  used 
  is 
  determined 
  first 
  by 
  the 
  general 
  character 
  of 
  

   the 
  vegetation, 
  using 
  a 
  small 
  one, 
  one 
  square 
  meter, 
  for 
  dense 
  

   closed 
  vegetation, 
  and 
  a 
  larger 
  one, 
  two 
  meters 
  square, 
  for 
  open 
  or 
  

   irregular 
  avssoclations. 
  The 
  quadrats 
  may 
  be 
  marked 
  out 
  by 
  

   four 
  stakes 
  connected 
  by 
  a 
  line 
  of 
  proper 
  length, 
  or 
  they 
  may 
  be 
  

   estimated 
  by 
  the 
  eye 
  with 
  sufficient 
  accuracy 
  for 
  all 
  practical 
  use. 
  

   The 
  optimum 
  size 
  can 
  be 
  ascertained 
  after 
  an 
  examination 
  of 
  the 
  

   preliminary 
  results, 
  and 
  the 
  survey 
  can 
  be 
  repeated 
  with 
  a 
  better 
  

   size 
  of 
  quadrat 
  if 
  the 
  first 
  is 
  unsatisfactory. 
  The 
  number 
  to 
  be 
  

   counted 
  depends 
  upon 
  the 
  visible 
  uniformity 
  of 
  the 
  association, 
  

   on 
  the 
  area 
  covered 
  by 
  it 
  and 
  on 
  the 
  time 
  available. 
  If 
  possible, 
  

   one 
  hundred 
  are 
  counted. 
  

  

  The 
  first 
  one 
  is 
  located 
  anywhere. 
  The 
  others 
  are 
  located 
  

   successively 
  in 
  a 
  pre-decided 
  relation 
  to 
  the 
  first, 
  thereby 
  obviating 
  

   any 
  element 
  of 
  personal 
  choice. 
  Thus 
  they 
  may 
  be 
  in 
  a 
  straight 
  

   line 
  and 
  separated 
  by 
  ten 
  paces 
  each, 
  so 
  that 
  the 
  whole 
  strip 
  of 
  

   one 
  hundred 
  would 
  be 
  one 
  kilometer 
  long; 
  or 
  they 
  may 
  be 
  in 
  a 
  

   square, 
  but 
  similarly 
  separated, 
  so 
  that 
  the 
  area 
  examined 
  would 
  

  

  M 
  

  

  be 
  approximately 
  loo 
  meters 
  square; 
  or 
  any 
  other 
  arrangement 
  of 
  

   separate 
  or 
  contiguous 
  quadrats 
  may 
  be 
  used, 
  depending 
  upon 
  

   the 
  configuration 
  of 
  the 
  association. 
  

  

  For 
  the 
  first 
  quadrat, 
  the" 
  species 
  are 
  listed 
  and 
  the 
  figure 
  i 
  

   placed 
  after 
  each 
  in 
  a 
  single 
  vertical 
  row. 
  For 
  the 
  second, 
  the 
  

   figure 
  2 
  is 
  placed 
  after 
  the 
  i 
  for 
  all 
  those 
  species 
  which 
  occur 
  also 
  

   in 
  the 
  second 
  quadrat, 
  and 
  new 
  names 
  followed 
  by 
  the 
  figure 
  2 
  

   are 
  added 
  for 
  the 
  additional 
  species. 
  The 
  process 
  is 
  continued 
  to 
  

   completion, 
  when 
  it 
  is 
  seen 
  that 
  some 
  of 
  the 
  species 
  occur 
  in 
  a 
  

   majority^ 
  of 
  the 
  quadrats 
  and 
  others 
  in 
  a 
  few 
  or 
  only 
  in 
  one, 
  and 
  

   the 
  common 
  species 
  are 
  distinguished 
  from 
  the 
  rare 
  ones 
  as 
  the 
  

  

  work 
  proceeds. 
  

  

  At 
  the 
  conclusion 
  of 
  the 
  count, 
  the 
  results 
  are 
  summarized 
  and 
  

   the 
  ratio 
  between 
  the 
  total 
  number 
  of 
  quadrats 
  and 
  the 
  number 
  

   in 
  which 
  a 
  particular 
  species 
  occurs 
  is 
  expressed 
  as 
  a 
  percentage 
  

   which 
  is 
  known 
  as 
  the 
  frequency 
  index^ 
  here 
  abbreviated 
  to 
  FI. 
  

   Thus, 
  the 
  frequency 
  index 
  of 
  a 
  common 
  species 
  may 
  be 
  as 
  high 
  as 
  

   100 
  and 
  most 
  associations 
  show 
  certain 
  species 
  with 
  Fl 
  90 
  or 
  

   more, 
  while 
  others 
  are 
  as 
  low 
  as 
  i. 
  

  

  Obviously 
  not 
  every 
  species 
  of 
  the 
  association 
  will 
  appear 
  in 
  

  

  