ECONOMIC BOTANY OF ALABAMA. 



Of the commoner beneficial mineral ingredients of 

 soils, lime is perhaps about equally common in both di- 

 visions, though varying greatly from one subdivision or 

 region' to another. The same might be said of phos- 

 phorus. Nitrogen and potassium are generally less 

 abundant in the coastal plain soils, except in the ''black 

 belt". 



On the average the coastal plain is considerably less 

 elevated and less hilly than the hill country. The latter 

 ranges from about 200 to 2,400 feet above sea-level, and 

 the former from sea-level to nearly 1,000 feet. This top- 

 ographic difference is due partly to the simple fact that 

 the coastal plain is nearer the coast, but partly also 

 to the fact that its rocks are younger and have never 

 become as indurated as some of those in the highlands. 

 The coastal plain exhibits a great variety of topography, 

 perhaps more in Alabama and Mississippi than anywhere 

 else (there being even some small "mountains" near the 

 boundary between these two states), but on the whole 

 its topographic forms are what would be called young. 

 That is to say, most of the streams have not yet carved 

 out wide valleys, and in the more level portions of the 

 area there are many swamps and ponds, which erosion 

 processes are tending slowly but surely (unless other 

 physiographic processes, such as solution of underlying 

 limestone, or warping of the earth's crust, interfere) to 

 do away with. 



As the coastal plain, by reason of its position next to 

 the coast, has almost certainly been submerged beneath 

 the sea at a later date than the hill country, its surface 

 is on the average not weathered so deeply, and the vege- 

 tation is of a newer, more "pioneer" type. The greater 

 abundance of evergreens in the coastal plain and scarcity 

 of potassium in the soil may be partly due either to this 

 fact, or to the prevalence of summer rains already men- 

 tioned, or to both. 



