a 

 Table 8-1. Systems for the Classification of Palustrine Areas 



Wetlands Classified According To the Form of The 

 Land Surface Upon Which They Have Become Established 



1. Depressed surfaces or hollows: 



A. Lake basins of the tarn type 



B. Shallow lake basins of the ordinary type 



C. Hollows not permanently filled with water 



D. Hollows in sand dunes 



E. Hollows formed by dams of various sorts 



II. Surfaces not hollowed out: 



A. Poorly drained till plains 



B. Broad divides 



C. Floors of glacial drainage valleys 



D. Lake and stream terraces 



E. Deltas of streams 



F. Slopes over which seepage spring waters flow 



G. Northern bogs in which peat forms on slopes 

 ("climbing bogs") often called raised bogs 



Wetlands Classified According To the Manner 

 In Which Their Peat Deposits Have Developed 



I. Those built up by successive generations of plants, starting from 

 what is now the bottom of the peat 



II. Those which have been formed by growth at the sides or at the top of 

 the basin or both: 



A. Inwash of dead and decaying vegetation from the shores into the 

 deeper parts of the lake basin 



B. Drifting of such materials from tributary streams 



C. Vegetation may grow out from shores to form 



floating mats, which ultimately cover entire water surface 



D. Floating, rootless plants which may develop abundantly at 

 or near water surface 



^Adapted from Davis 1906. 



(Continued) 



8-3 



10-80 



