﻿92 
  Nichols: 
  The 
  vegetation 
  of 
  Coxxecticut 
  

  

  II. 
  HABITAT 
  FACTORS 
  ALONG 
  THE 
  SEACOAST 
  

  

  The 
  character 
  of 
  plant 
  associations 
  along 
  the 
  seacoast, 
  both 
  

  

  above 
  and 
  below 
  high 
  tide 
  level, 
  shows 
  the 
  influence 
  of 
  the 
  sea 
  in 
  

  

  various 
  ways 
  and 
  to 
  various 
  degrees. 
  Some 
  of 
  the 
  ways 
  In 
  which 
  

  

  this 
  influence 
  is 
  expressed 
  are 
  summed 
  up 
  in 
  the 
  following 
  para- 
  

   graphs. 
  

  

  A. 
  Influences 
  associated 
  with 
  submergence 
  in 
  sea 
  water 
  

  

  Salinity 
  of 
  sea 
  water. 
  — 
  ^This 
  very 
  naturally 
  holds 
  first 
  rank 
  

   among 
  the 
  factors 
  responsible 
  for 
  the 
  peculiarities 
  of 
  vegetation 
  

   which 
  is 
  within 
  actual 
  reach 
  of 
  the 
  salt 
  water. 
  It 
  results 
  primarily 
  

   in 
  the 
  exclusion 
  of 
  many 
  plants 
  and 
  plant 
  associations 
  which 
  are 
  

   present 
  in 
  similar 
  situations 
  along 
  the 
  shores 
  of 
  large 
  bodies 
  of 
  

   fresh 
  water, 
  such 
  as 
  the 
  Great 
  Lakes, 
  and 
  in 
  the 
  presence 
  of 
  many 
  

   others, 
  notably 
  the 
  marine 
  algae, 
  which 
  are 
  not 
  represented 
  else- 
  

   where. 
  

  

  The 
  water 
  of 
  the 
  open 
  ocean 
  In 
  the 
  North 
  Atlantic 
  contains 
  

   about 
  3.3 
  per 
  cent 
  of 
  salt. 
  Along 
  practically 
  its 
  entire 
  length 
  

   the 
  Connecticut 
  coast 
  faces 
  on 
  Long 
  Island 
  Sound, 
  and 
  the 
  salinity 
  

   of 
  the 
  Sound 
  water 
  is 
  considerably 
  lower 
  than 
  that 
  of 
  the 
  open 
  

   ocean.* 
  This 
  difference 
  in 
  salinity 
  is 
  to 
  be 
  expected, 
  since 
  the 
  

   Sound 
  is 
  partially 
  shut 
  off 
  from 
  the 
  ocean 
  by 
  Long 
  Island 
  and 
  

   has 
  several 
  large 
  rivers 
  emptying 
  into 
  it. 
  The 
  difference 
  is 
  of 
  

   importance, 
  because 
  it 
  is 
  doubtless 
  correlated 
  with 
  the 
  absence 
  

   or 
  scarcity 
  in 
  many 
  parts 
  of 
  the 
  Sound 
  of 
  seaweeds 
  which 
  are 
  

   abundant 
  in 
  similar 
  situations 
  along 
  the 
  open 
  ocean. 
  All 
  inter- 
  

   gradations 
  are 
  to 
  be 
  found 
  along 
  the 
  coast 
  and 
  in 
  the 
  adjoining 
  

   waters 
  between 
  areas 
  in 
  which 
  the 
  water 
  is 
  strongly 
  saline 
  and 
  

   areas 
  in 
  which 
  it 
  is 
  fresh, 
  and 
  these 
  variations 
  in 
  salinity 
  are 
  

   accompanied 
  by 
  corresponding 
  variations 
  in 
  vegetation. 
  

  

  The 
  tides. 
  — 
  Marine 
  algae 
  which 
  gro\\ 
  

  

  from 
  

  

  that 
  grow 
  at 
  lower 
  levels. 
  For 
  a 
  longer 
  or 
  shorter 
  period 
  each 
  

  

  * 
  According 
  to 
  Graves 
  (08) 
  the 
  salinity 
  of 
  the 
  water 
  in 
  the 
  open 
  Sound 
  near 
  

   New 
  Haven 
  is 
  about 
  2.8 
  per 
  cent. 
  This 
  figxire 
  probably 
  represents 
  a 
  fair 
  average 
  for 
  

   the 
  entire 
  area, 
  but 
  of 
  course 
  there 
  is 
  considerable 
  difference 
  between 
  the 
  salt-content 
  

  

  of 
  the 
  water 
  westward 
  from 
  New 
  Haven, 
  toward 
  the 
  head 
  of 
  the 
  Sound, 
  and 
  east- 
  

   ward, 
  toward 
  its 
  mouth. 
  

  

  