FOREST RESOURCES OF THE NORTH-LOUISIANA DELTA 



General Description 

 of the Unit 



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THE north-Louisiana delta survey unit in- 

 cludes the flood plains of the Mississippi 

 Basin that are north of the Red River in 

 Louisiana and south of Vicksburg in Mississippi. 

 These flood plains, shown in figure 1, extend west to 

 the hills in the former State and east to the bluffs 

 in the latter. The total land area, exclusive of 

 meandered lakes and rivers, is 3,897,000 acres, of 

 which 250,200 acres are in Mississippi. 



Topography and Drainage 



Local streams are numerous, large, winding, and 

 sluggish. During flood times, soil-laden waters 

 overflow the river banks and drop their alluvium. 

 Much soil settles near the stream margins; less, 

 farther back. In this manner low ridges or "front 

 lands" are built up along each river bank. Rivers 

 also scour away their banks on the convex side of 

 bends and build up mud and sand bars elsewhere. 

 This constant shifting of streams possibly justifies 

 the assertion that at one time or another every acre 

 of the Mississippi River bottom land was actual 

 stream bed. 



Before the construction of the present levee sys- 

 tem, much of this section was subject to a spring 

 flood nearly every year. Exceptional floods covered 

 all but the highest part of Macon Ridge and a few 

 of the higher river margins. The present levee 

 system affords much better protection. Excep- 

 tionally destructive floods, such as those in 1927, 

 may cover wide areas, but ordinary high waters 

 now cover only the extensive flats lying south of 

 Jonesville and Ferriday. Annual inundation in 

 some degree, however, either by overflow or con- 

 centration of local rain water is characteristic ol 

 the stippled areas shown in figure 1. Elsewhere 

 rainfall during the winter season covers the bottoms 



of local streams and restricted areas on the lower 

 flats. This survey unit as a whole, however, is not 

 characteristically a swamp country; swamps, 

 properly speaking, are of restricted occurrence. 



The unit is made up entirely of present flood 

 plains or first bottoms and of ancient flood plains 

 in the form of second bottoms and higher terraces. 

 The present flood plains seldom vary more than 1 2 

 to 15 feet in elevation, the higher elevations lying 

 along courses of present or former streams. Macon 

 Ridge, rising about 30 feet above the present flood 

 plain, is the unit's principal topographic feature. 



Soils 



The soils of this unit fall naturally into three 

 distinct soil groups (fig. 1). The first group is 

 characteristic of the present flood plain of the 

 Mississippi River itself, and lies east and south of 

 Macon Ridge. The second is found on the present 

 flood plains of the Ouachita and Boeuf River sys- 

 tems. The third group occurs on Macon Ridge 

 itself and on the adjacent lower terraces or second 

 bottoms to the west. 



Soils of the Mississippi River flood plain are 

 typically gray to black and vary from pure clays to 

 very fine silty sand. Sands and sandy clays make 

 up most of the natural levees or low ridges adjacent 

 to present or former streams. Alternating with 

 these sandy ridges are flat, poorly drained areas 

 where the soils vary from silty clays to impervious 

 waxy clays. South of Macon Ridge, clay soils 

 predominate. 



On the flood plains of the Ouachita and Boeuf 

 River systems reddish soils prevail. They are 

 chiefly deposits of alluvium from the Arkansas 

 River brought down through Bayou Bartholomew 

 and the Boeuf River. Those soils also vary in tex- 



