Transect C. The larger decrease in nonvegetated ground occurred 
from 1954 to 1955, rather than from 1955 to 1956, on two vegetative 
types of Transects A and one of Transect C--types consisting of 
Saltmeadow cordgrass with small amounts of Olney's three-square. 
Two vegetative types not shown in figures 2-9 had the following 
percentages of nonvegetated ground: 
Transect A, reed type 
Transect C, saltmeadow cordgrass 
in buggy trail 
1954 1955 1956 
69.0 46.7 45.7 
63-3 57.2 22.3 
The extent of nonvegetated ground increased for Transect D 
from 1954 to 1956 and remained approximately the same for Tran- 
sect E. 
Probabilities of chance occurrence of t values of a similar 
magnitude for these changes in amount of nonvegetated ground are 
as follows: 
Transect A 1954 to 
1955 to 
Transect B 1955 to 
Transect. C 1954°to 
1955 to 
Transect D 1954 to 
1955 to 
1955 
1956 
1956 
1999 
1956 
1995) 
1956 
0.01 
0.02 
0.06 
0.01 
0.12 
0.01 
(105 samples) 
(105 samples) 
( 51 samples) 
( 46 samples) 
( 46 samples) 
( 16 samples) 
( 16 samples) 
The extent of large openings increased from 1954 to 1955 for all 
vegetative types of Transect A, but decreased by 1956. Large openings 
10 
