37 



pear gain a foothold and stabilize ihe sands. A scrubby forest may then 

 develop. Of the trees native to the sand areas, black oak (Q. vcliitina) 

 is the commonest. In the southern areas black-jack oak (0. inariland- 

 ica) is common, and in the northern areas bur oak (0. macrocarpa) oc- 

 curs frequently. Hickory (Carya cordiformis Wang.) and white oak 

 (Q. alba) are found throughout the sand regions, but their presence gen- 

 erally indicates better soil conditions. 



The tabulation on page 11 shows that the representation of species 

 by per cents based on measurements covering 7.68 acres in five counties, 

 is as follows: black oak. 63.2; scrub oak, 25.6; white oak, 2.6; and hick- 

 ory, 8.3. 



Extensive areas of sand, in the form of dunes or river and lake de- 

 posits, are known to exist in twenty-eight counties of the central and 

 northern parts of the state. The State Soil Survey has covered twenty- 

 six of these counties, computing the sandy areas in twenty. In the re- 

 maining six, these areas have been estimated from maps completed but 

 not yet measured. In two counties where sand deposits exist, no infor- 

 mation as to their area is available. The twenty-six counties show ap- 

 proximately 221,000 acres of dune sand and 71.000 acres of river and 

 lake deposit sand. The greater part of the sand deposits of the state are 

 included in these twenty-six counties, and the total area of the state 

 covered by sand is at least 310,000 acres. (See Map II, facing p. 1.) 



The delineation of those areas in the sandy region which were origin- 

 ally forested is less reliable than for non-sandy soils. The organic car- 

 bon contents in the upland prairie loams are decidedly greater than in 

 the upland timber soils, and in the field the transition from prairie to 

 timber soil is readily apparent in the lighter color of the latter. The 

 organic carbon content of sands is not markedly greater for prairie sand 

 than for timbered sand, and in neither case is sufficient to give a decided 

 color to the soil. About 75 per cent of the sand soils are classified by 

 the Soil Survey as terrace soils. Such soils in this study are considered 

 upland soils, and are generally regarded as originally non-forested. At 

 present considerable areas of such land are forested with even-aged stands 

 of an age roughly corresponding to the period which has elapsed since the 

 region was settled. 



The total area included in the scrub oak type is 2,145.120 acres, of 

 which 20.94 per cent is estimated to have been forested originally, and 

 of which 4.26 per cent is at present forested. Within the general areas 

 covered by this 2,145,120 acres are 310,000 acres of pure sand and the 

 balance of the area has soil of a generally sandy nature. The sandy 

 loams have been cleared and the 91.011 acres of the scrub oak type now 

 wooded are largely on poor sand land. 



While forests are justified here solely on their ability to check the 

 drift of sands upon neighboring fertile soils, yet the stands native to the 

 site are stunted and scrubby. Black oak commonly attains a height of 

 50 feet with a clear bole of 10 feet and with a bushy crown. The prod- 

 ucts from such forests have little value other than for fuel and post ma- 



