42 



ECOLOGICAL RELATIONS OF THE FLORA. 

 Quadrats. 



Plants. 



A spidium thelypteris . 

 Phragmites communis . 



Iris veriscolor 



Salix nigra 



Polygonum persicaria . 

 Lobelia spicata 



1 



15 

 90 



108 



10 

 105 



4 



129 



6 



70 



78 



35 



60 



102 



5 

 102 



107 



Av. 



14 



85 



1 



102 



If evenly spaced, each plant would have had about 100 sq. cm. to 

 itself — a sparse vegetation considering the linear-leaf habit of the 

 majority of the species. 



Bush Swamp Formation — Ahius Association: Wherever the ground 

 was dryer than in the main portion of the meadow, due to the mounds 

 formed by the vegetation, the bush swamp formation began. The 

 pioneers seemed to be Rosa Carolina and Spiraea salicifolia, but these 

 by no means dominated the resulting thicket (Plate VI b). In these 

 thickets a dense shade prevailed and mosses (Amblystegium riparium 

 longifoliuni and Polytrichium sp.) with mushrooms, (Marasmius rotula, 

 Omphalia, Russula veternosa media) formed the bottom laj^er. On 

 the borders of the thicket the vegetation was plainly terraced, the 

 shorter forms being toward the front and the taller ones in the 

 center. 



. The ground around the thickets was completely built up so that there 

 was no marshy vegetation in the series. Yet it was no doubt the case 

 that in spring and wet seasons these plants were submerged for a time. 

 This feature, together with its origin, classes the bush swamp with the 

 helophytes, although it may pass directly into a mesophytic woods or 

 wooded swamp, depending on the water relation. A pecuharity in 

 the development of this feature was shown by the trunks of Larix 

 laricina found in the peat and in some cases still standing. These 

 trees had been destroyed by fire or by lumbering but they inchcated 

 a phase of the development of the forest not shown by anything on the 

 Point. The presence of Andromeda, Menyanthes, Utricularia, Thuja, 

 etc., also point to an oxylophytic formation or at least oxylophytic 

 conditions. The better drainage and the resulting aeration of the soil 

 in these hammocks were doubtless in large part responsible for the 

 fact that this oxylophytic formation disappeared and was replaced by 

 the nlants of the shrubbv growth-form. 



