2.. 
water table oocurring at a depth les than 18 Inches are subject 
to heaving and their reforestation reqires the use of cuttings 
or special planting technique. 
SsaUpport grass vegetation. The adaptation 
of soils within this group varies depending upon the drainage and 
depth of overwash deposit of silt. The application of mineral 
fertilizers was fond to be essential In order to restablish 
the original prairie cover on these soils, 
Ogn     a      el                osits include peat, muck, 
mprl an beach sand, These typos support a number of water- 
loving associations such as sedge., cat-tails, t lows, ad 
cottonwood. The distribution of these forms Is determined by 
the nature of the dposits. Cottonwood, alder, willow and white 
cedar are the principal speclo to be considered in reforesting 
these sites. 
In numerous Instances the mutual relationship of organisms 
and soil conditions is sharply defined an apparent even to the 
casual observer; In other cases, the correlation is masked by 
mants activity and my only be disclosed throg     a study of 
analytical data. The post-settlement period has brought manifold 
changes in the composition of plant-animal comscnities. The 
cutting of the valuable species and the destruction of natural 
reproduction by grazsng resulted in the invasion of infested 
sprouts and a gneral degeneration of the forest. The original 
al-aged associations of trees and herbacecus plants gave place to 
even-aged stands largely depleted of ground cover, The prairie and 
meadow grasses were replaced by cultivated plants with a xubse- 
quent modification In the status of birds and me.mals The