﻿208 Nichols: The vegetation of Connecticut 



open ditch, or fosse, which at certain seasons of the year may- 

 be filled with water to a depth of one or two feet. This ditch is 

 a widespread feature of bogs and its significance is not yet wholly 

 clear. But of the various explanations offered, that suggested by 

 Davis* seems to the writer most plausible. Davis attributes the 

 formation of the fosse to " the fluctuation of the water level through 

 rather brief intervals and the constant recurrence of these fluctu- 

 ations. These are attendant upon the variations in the rainfall, 

 and the water level in the lakes and depressions may vary one, two, 

 or more feet every few years, and may remain at the low water 

 stage for several years in succession. . . . It is also a matter of 

 observation that, during dry times, the water does disappear from 

 these marginal ditches for long periods during the summer and 

 autumn, the bottoms becoming quite dry, and this has the effect of 

 destroying much of the hydrophytic vegetation which has estab- 

 lished itself and also of thoroughly decomposing and disintegrating 

 the organic matter which has accumulated during periods of high 

 water." In this way the surface is lowered " below that of the area 

 directly above the zone of permanent water, which, being covered 

 by a thicker layer of vegetable debris, is kept wet by the upward 

 capillary movement of the water from below its surface," 



The Tree Stage in Bogs. — The most distinctive feature of the 

 tree stage in Connecticut bogs, considered collectively, is the 

 presence of the black spruce. Commonly associated with this, 

 and sometimes forming considerable forests in the older, better 

 drained portions of the bog, grows the tamarack. The tamarack 

 is not so tolerant of shade as the black spruce, but its more rapid 

 and greater height growth enable it to maintain its own in the 

 competition for light. More or less extensive tamarack forests 

 formerly occurred in bogs at New Fairfield, Suffield, and else- 

 where. Due to the rather open character of such forests, and the 

 slight shade produced by the tamarack, the spruce, together with 

 much of the undergrowth present in the adjoining parts of the open 

 bog persists here. The black spruce itself seldom forms a stand of 

 sufficient height and density to merit the title of forest; but in the 

 cool highlands of northwestern Connecticut, about Bingham Pond 



* 1907, loc. cit., p. 151. For references to other explanations see Cooper, loc. cit.. 



