iir 



d. Alluvial strips along the secondary streams throughout the 

 state. Soils are mixed loams and fertile. Basswood is a common tree 

 in the northern region and black walnut grows freely. 



e. Sand-plains and dunes. — These are found along the middle Illi- 

 nois River in Mason county, southern Whiteside, and western Lee, Hen- 

 derson, Kankakee, Grundy, and Iroquois counties. While found on and 

 near bottoms they yet may have a desert vegetation. Black-jack oak 

 (Querciis marilandica) is found on the poorer sites, with black oak, 

 hickory, and white oak on the better ones. The types d and e are really 

 intermediate between bottomland and upland types. 



UPLAND 



a. Ocark upland. — This is upland south of the limit of ice invasion, 

 extending from southern Jackson county through southern Williamson, 

 Saline, Pope, and Gallatin counties. Characterized by beech, hard maple, 

 red, black, white, and shingle oaks, hickories, tulip-poplar, ash, red gum 

 and black, elm, wild black cherry, black walnut, and cucumber-tree. 



b. Loessial uplands bordering the Mississippi, Illinois, and Wabash 

 river flood-plains. In the south, along the Mississippi and Wabash 

 rivers, are found all species common to the Ozark upland and, in locali- 

 ties, considerable basswood in addition. 



c. Gray silt loam uplands of the Illinois glaciation, in the interior 

 of the state extending from the Ozark uplands north to the Wisconsin 

 moraine and black soil belt. Characterized by post, black, shingle, white, 

 and pin oaks and hickory. 



d. Ycllozv silt loam uplands of central and northern Illinois. 

 Characterized by a good growth of black, white, and burr oak, and 

 hickory, with black walnut and black cherry on the better and scrub 

 oak on the poorest soils. 



The tamarack swamps of Lake county, the white pine of Ogle 

 county, and the shortleaf jjine in Union, Jackson, and Randolph counties 

 are of ecological interest but are not important timber types. 



Included in these forest areas at present are stands of every size 

 and all ages from saplings to over-mature virgin stands. In general the 

 bottomland stands throughout the state show a greater diversity of 

 species than the upland stands and are not usually even-aged. Again, 

 in uplands of the southern part of the state, removal by species or by 

 occasional larger trees has resulted in stands of uneven age. In the 



