﻿r 
  

  

  Nichols; 
  The 
  vegetation 
  of 
  Connecticut 
  543 
  

  

  \ 
  

  

  r 
  

  

  tions 
  during 
  the 
  development 
  of 
  the 
  marsh 
  must 
  have 
  followed 
  

   the 
  same 
  order 
  as 
  the 
  zoned 
  series 
  of 
  associations 
  which 
  is 
  to 
  be 
  

   encountered 
  along 
  the 
  outer 
  edge 
  of 
  most 
  marshes, 
  in 
  proceeding 
  

   from 
  the 
  muddy 
  bottoms 
  of 
  the 
  sublittoral 
  upward 
  to 
  the 
  grassy 
  

   meadows 
  of 
  the 
  upper 
  littoral. 
  As 
  will 
  be 
  brought 
  out 
  presently, 
  

   however, 
  this 
  hypothetical 
  correspondence, 
  though 
  formerly 
  

   accepted 
  as 
  a 
  fact 
  (see 
  Shaler, 
  ^85, 
  etc.), 
  would 
  seem 
  to 
  be 
  merely 
  

   apparent. 
  ^ 
  ' 
  ' 
  

  

  The 
  actual 
  succession 
  of 
  plant 
  associations 
  and 
  its 
  probable 
  

   explanation. 
  — 
  In 
  attempting 
  to 
  work 
  out 
  the 
  successional 
  relations 
  

   of 
  any 
  given 
  series 
  of 
  plant 
  associations 
  there 
  are 
  various 
  methods 
  

   of 
  procedure, 
  but 
  all 
  of 
  those 
  customarily 
  employed 
  necessarily 
  

   are 
  based 
  on 
  the 
  study 
  of 
  the 
  existent 
  vegetation. 
  In 
  the 
  large 
  

   majority 
  of 
  cases, 
  therefore, 
  conclusions 
  regarding 
  the 
  nature 
  of 
  

   any 
  given 
  successional 
  series, 
  where 
  this 
  extends 
  over 
  a 
  period 
  of 
  

   time 
  beyond 
  that 
  during 
  which 
  the 
  area 
  in 
  question 
  is 
  actually 
  

   under 
  observation, 
  must 
  be 
  founded 
  wholly 
  on 
  circumstantial 
  

   evidence. 
  It 
  is 
  of 
  course 
  inevitable 
  that 
  any 
  deductions 
  regarding 
  

   the 
  future 
  course 
  of 
  succession 
  should 
  be 
  largely 
  hypothetical, 
  

   and, 
  except 
  in 
  the 
  comparatively 
  few 
  instances 
  where 
  historic 
  

   records 
  are 
  available 
  or 
  where 
  a 
  fossil 
  record 
  has 
  been 
  left 
  by 
  suc- 
  

   cessive 
  generations 
  of 
  preexistent 
  plants, 
  any 
  reconstruction 
  of 
  

   the 
  course 
  of 
  events 
  in 
  the 
  past 
  must 
  likewise 
  be 
  largely 
  assumed 
  

   from 
  theoretical 
  deductions. 
  Salt 
  marshes, 
  however, 
  resemble 
  

   peat 
  bogs 
  in 
  that 
  conditions 
  have 
  favored 
  the 
  preservation 
  of 
  a 
  

   fossil 
  record, 
  since 
  they 
  are 
  usually 
  underlain 
  by 
  peat 
  deposits 
  

   which 
  may 
  extend 
  to 
  a 
  depth 
  of 
  many 
  feet, 
  and 
  the 
  study 
  of 
  these 
  

   salt 
  marsh 
  peat 
  deposits 
  has 
  yielded 
  some 
  ver>- 
  significant 
  facts. 
  

  

  Assuming 
  the 
  vertical 
  or 
  historic 
  order 
  of 
  succession 
  during 
  

   the 
  development 
  of 
  the 
  marsh 
  to 
  have 
  been 
  coordinate 
  with 
  the 
  

   present 
  day 
  lateral 
  sequence 
  of 
  zones, 
  as 
  set 
  forth 
  in 
  the 
  second 
  

   paragraph 
  above, 
  the 
  peaty 
  and 
  mucky 
  deposits 
  underlying 
  a 
  salt 
  

   marsh 
  should 
  show 
  approximately 
  the 
  following 
  sequence 
  of 
  

   layers, 
  from 
  below 
  upward: 
  (i) 
  a 
  layer 
  of 
  silt, 
  with 
  remains 
  of 
  eel 
  

   grass, 
  extending 
  from 
  a 
  variable 
  depth 
  to 
  low 
  tide 
  level; 
  (2) 
  a 
  

   layer 
  of 
  silt, 
  with 
  but 
  few 
  vegetable 
  remains, 
  extending 
  from 
  low 
  

   tide 
  level 
  up 
  to 
  the 
  level 
  at 
  which 
  the 
  salt 
  marsh 
  grass 
  becomes 
  

   established 
  ; 
  (3) 
  a 
  layer 
  of 
  muddy 
  peat 
  with 
  more 
  or 
  less 
  abundant 
  

  

  