﻿184 Nichols: The vegetation of Connecticut 



Most of the plants characteristic of the bulrush — pickerel-weed — 

 cat- tail stage in the lake-swamp succession are provided with more 

 or less extensive rhizome systems, which ramify near the surface 

 of the mucky substratum, thereby tending to make the bottom 

 more solid. The building up of the substratum proceeds much 

 more rapidly as the depth of the water decreases, due partly to 

 the denser plant population of the shoreward zones, as compared 

 with those farther lakeward, and partly to the fact that mechanical 

 tissues, which naturally resist decay, are much more highly de- 

 veloped in plants with aerial organs than in plants which are 

 entirely or for the most part submerged. 



Succession in Lake Swamps. — As soon as the bottom of a 

 pond has been built up high enough so that the substratum is 

 exposed during part of the year, aquatic plants begin to give way 

 to terrestrial species. For the sake of convenience, the various 

 stages in the succession up to this point may be referred to col- 

 lectively as the Lake Series, aiid the subsequent stages as the 

 Swamp Series. But it is manifestly impossible to draw a sharp 

 line of demarcation between the two; for not only are various 

 species of the bulrush — pickerel-weed — cat-tail association quite 

 characteristic of wet swamps, but it is often easy to observe within 

 this zone, along the shore of a lake, a gradual transition from lake 

 on the one hand to swamp on the other. The bulrush — pickerel- 

 weed — cat-tail stage, then, represents a connecting link between 

 the vegetation of lakes and that of swamps. Swamps which 

 have originated through the filling in of a lake or pond, after the 

 manner above described, may be termed Lake Swamps. 



Almost always, in a succession like the one under discussion, 

 the first true land plants to appear in the succession are sedges; 

 hence, the first swamp stage is known as the Sedge Stage. To a 

 greater degree than any of the plants that have preceded them, 

 the sedges are equipped with tough rhizomes and copious slender 

 roots, through the interweaving of which the soil is more firmly 

 bound together and converted into a compact turf. By far the 

 commonest, and ecologically the most important, sedge of Con- 

 necticut swamps is Carex stricta, a species which is readily recog- 

 nized from its tussock-forming habit (Fig. 8) ; but frequently other 

 plants with grass-like foliage are equally or even more prominent. 



