THE BOGS AND BOG FLORA OF THE HURON RIVER 
VALLEY. 
EDGAR NELSON TRANSEAU. 
(WITH SIXTEEN FIGURES) 
[Continued from p. 375.] 
THE BOG AS A HABITAT FOR PLANTS. 
WHEN we consider the bog as a habitat for plants, there is at once — 
brought to mind the marked contrast between its characteristics and 
those of the other plant habitats of its vicinity. In both its atmos- ~ 
pheric and edaphic conditions it is unique. The various factors 
entering into the plant environment will be discussed as physical, 
chemical, and biotic agents. 
A. Puysicat Factors.—1. Wind.—Because of the fact that so 
large a number of our bogs lie in depressions surrounded by hills, 
the influence of the wind is somewhat lessened. It is only in the - 
case of the larger basins that its effects become marked. It has been 
noted by several students of bogs (41, 5) p- 373 59) 47) that in the 
region of prevailing westerly winds the greatest development of bog 
areas and peat deposits occurs on the western sides of lake basins. 
Where the deposition has taken place in a large lake basin, which 
is now only partially filled, we commonly find open water occurring 
toward the eastern side. The peat deposits at Portage, Parks, and 
West Lakes in the vicinity of Ann Arbor are massed on the western — 
shores, while the eastern margins exhibit an ordinary lake beach. At 
the bogs north of Delhi, although nine-tenths of the original basin has 
been filled, the two small lakes are near the eastern margin. T. J 
facts noted in this region all favor the idea of the bog plants being 
unable to gain a foothold on the eastern side in the presence of wave 
action. The shoreward thrust of the ice is of importance at times In 
this connection. 
Farther north in Michigan the wind frequently shows its ext 
effect in these bog areas in the presence of “windfalls.” Owing = 
the character of the substratum, such areas are more readily affected 
[DECEMBER 
reme 
418 
