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by overflow areas on such streams as the Kaskaskia, Big Muddy, 

 Cache, and Little Wabash. Sand, silt, loam, or clay may be on the 

 surface of these bottomlands, but the subsoil is usually clay. The 

 forest type characteristic of this class of lands comprises many rapid- 

 growing and valuable species in mixtures varying with the soil and 

 soil moisture. 



BOTTOMLAND TYPE 



General Characteristics. — The most important trees of the southern 

 Illinois bottomlands are pin oak, elm, sweet gum, the hickories, white 

 oaks, soft maple, ash, willow, and cottonwood. Big shellbark, mocker- 

 nut, water, pecan, and bitternut hickories are the chief representatives 

 of that genus. Practically all of the lowland white oaks are present, 

 including swamp white, white, cow, overcup, and bur oaks. The follow- 

 ing species, while characteristic, are either fewer in number or more 

 restricted in their distribution : cypress, river birch, swamp Spanish 

 oak, hackberry, sycamore, honey locust, coffeetree, black and tupelo 

 gums, and catalpa. The broad level stretches subject to occasional 

 overflow are covered with a mixture in which either pin oak or sweet 

 gum predominates. Wetter situations are often occupied by elm and 

 soft maple. Willow and cottonwood are characteristic of newly-made 

 land, especially along the larger watercourses, while river birch and 

 sycamore follow the smaller streams. The best quality white oaks 

 and shagbark hickory grow where drainage conditions are most favor- 

 able, often on low, sandy ridges. There is little underbrush, since 

 as a rule the stands are dense. Where it does occur, it usually consists 

 of tree species, mixed with hawthorn, buttonbush, cat-briar, Hercules 

 club, pawpaw, boxelder, and redbud. Vines, poison ivy, and rank 

 weeds also obstruct passage through the woods. 



Mississippi River. — The proportion of forest land for the Missis- 

 sippi bottoms grows less going northward, varying from forty and 

 forty-five per cent in Alexander and Union counties to twelve per cent 

 in Randolph. North of Randolph the forest is confined to a strip 

 along the river and a few scattered woodlots. The Alexander County 

 bottoms also contain more beech, hackberry, black gum, cypress, and 

 tupelo than those farther north. Sweet gum, which forms twenty- five 

 per cent of the stand in Alexander County, is rarely found north of 

 Raddle in northern Jackson County. On the whole, the Mississippi 

 bottomlands are thoroughly cut over, and few good stands of saw- 

 timber remain. The merchantable timber averages about 2,000 to 

 2,500 board feet per acre, while the best stands will contain 8,000 to 

 12,000 board feet. 



