FIG. 7-6 Profile of a bog pUnf sere (from Dansereau and Segedas-Vienne 1952). 



BOG FOREST 



I 1 



Water Folse bottom Sedge peat 



Sphagnum peot Woody peot 



m Enmi] 



mzi 



Parent rock Altered rock Humus loyer Live sphagnum Mesic mosses 



B- horizon A-horizon 



thos, and nekton, as do lakes ; in addition, neuston is 

 present. Species that constitute these life-forms are 

 mostly different from those in lakes. In ponds pul- 

 monate snails replace the gilled snails of lakes, and 

 clams are of lesser importance. Air-breathing adult 

 beetles and bugs, mostly absent from the lake biocies, 

 are often abundant. Adult stages of aquatic insects 

 and terrestrial forms occur in the surrounding marsh. 

 Fish spend most of their lives in the ponds, but go 

 into the marshes to reproduce. Amphibians, reptiles, 

 birds, and mammals are usually numerous. 



Food-chains in ponds and marshes are based in 

 part on detritus, bacteria, and phytoplankton, true 

 also of lakes ; and, in part, on rooted plants, the 

 periphyton that covers them as well as other objects 



in the water, and filamentous algae. Biomass and 

 productivity are usually greater in ponds than in 

 lakes. Ponds, however, may become stagnant during 

 dry periods, especially in late summer, with great ad- 

 verse affect upon their carrying capacity. Pond and 

 marsh management for high economic yield of fish, 

 waterfowl, and muskrats requires control of the water 

 level and control over plant succession ; an incidental 

 problem is mosquito control. The unique adapta- 

 tions and behavioral adjustments of animals to meet 

 the critical periods of summer stagnation and winter 

 freezing, characteristic of ponds, are most interesting. 

 Ponds and marshes are available to all ecologists for 

 the study of the life-cycles and adjustments of animals 

 in the pond-marsh biocies. 



Ponds, marshes, swamps, and bogs 95 



