4 ILLINOIS NATURAL HISTORY SURVEY MANUAL 3 



forests have been destroyed, but forest remnants that have es- 

 caped destruction harbor a large number of shrub species, and 

 non-arable and abandoned portions of the prairie support a 

 smaller number. The completeness with which prairies and 

 forests have been sacrificed to the interests of agriculture and 

 industry has affected as markedly the abundance and distribu- 

 tion of shrubs as of trees, grasses and herbs. But, fortunately 

 for the plant lover, many kinds of shrubs survive in out-of-the- 

 way, neglected corners, in woodlots, along streams, roadsides 

 and fence rows, and in young forest growth that has been per- 

 mitted to spring up following destruction of the original forest. 



The Prairie. — In the great expanse of land once grass covered 

 but now given over to plowed fields, small differences in soil, 

 elevation and exposure provide opportunity for the existence 

 of a wide variety of shrubs such as the Prairie Willow, Dwarf 

 Pussy Willow, Meadow Spirea, Prairie Rose, Leadplant and 

 Wolfberry. Stream margins support numerous wallows, and 

 prairie groves and timber along larger streams encourage 

 thickets of varied composition. Plow-broken land, when aban- 

 doned, is often covered with sumac and brambles. 



The Forest Margin. — In general, the richest growth of 

 shrubs takes place at the forest edge. Here the transition from 

 forest to prairie is accompanied by changes in soil, moisture, 

 sunlight, shade, protection and other factors that furnish con- 

 ditions ideal for many types of shrubs. 



The Forest. — Within the forest itself the number of kinds of 

 shrubs is large, also. Here shrubs, especially adapted to life in 

 deep shade, still air and a humid atmosphere, form a dense, low 

 understory beneath such lesser trees as Ironwood, Blue Beech 

 and Redbud. Here, also, climbing woody vines are numerous. 



Lake Michigan Moorlands. — ^This region, which extends 

 some distance inland along the shore of Lake Michigan, is 

 characterized especially by its sandy soil, which ages ago was 

 arranged by the action of the lake and later by wind into great, 

 flat reaches, shallow swales and swelling dunes. Low-lying por- 

 tions have remained until recently as marshes. In this region 

 Common Juniper, Speckled Alder, Alder-Leaved Buckthorn, 

 Jersey-Tea, Buffaloberry, Bearberry and American Cranberry- 

 bush are characteristic shrubs. 



Cold Bogs. — ^An exceedingly interesting habitat is the bog 

 area in Lake and McHenry counties. Many small lakes and 



