FOREST 



RESOURCES 



O F 



THE 



NORTH-LOUISIANA 



DELTA 



Forest Description 



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THE forest area of the survey unit is in general 

 a mixed hardwood forest, whei^e the typical 

 stand is made up of trees of many sizes and 

 ages. More than 20 percent still bears uncut old- 

 growth timber. Nearly 80 percent has at one time 

 or another been cut over for sawJogs or other forest 

 products. At the time of cutting, these areas were 

 largely stripped of the timber that had the quality 

 required by the lumber, veneer, and cooperage in- 

 dustries. Nevertheless, at the present time nearly 

 64 percent of the total board-foot volume in the 

 survey unit is found on areas once cut over. Al- 

 though a part of this volume is in residual trees left 

 at the time of logging, more than 40 percent is found 

 in trees less than 19 inches in diameter. In addi- 

 tion, nearly 8 million cords of wood are found in 

 trees below sawlog size. Growth of trees less than 

 19 inches in diameter is rapid. Because this rapid- 

 growing component of the forest is increasing its 

 volume very much faster than it is being used, a 

 relatively large growing stock is being built up on 

 which future operations may depend. With shifts 

 in market, changes in technical processes of manu- 

 facture, and improvement in timber quality as a 

 result of growth, this growing stock of residual and 

 second-growth timber can eventually serve as the 

 basis for commercial cuttings. 



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forest types are shown in a broad and generalized 

 manner on the map at the end of this report. Areas 

 of the other two types are too small or scattered to 

 be included. Because the distribution of these 

 types was seen to be closely related to topography, 

 the forest area was classified in the field into four 

 topographic-situation classes, defined as follows: 



Swamp. — Forested areas normally under water during the 

 greater portion of the year. 



Terrace. — Nonswampy ancient flood plains now above the 

 level of all but exceptional floods. 



River margin. — Relatively high sandy areas adjacent to 

 present or recent stream courses and comprising the most 

 recent alluvial deposits in the delta. 



Bottomland. — Present flood plains which cannot be classified 

 as swamp or river margin. 



As shown in table 4, three-fourths of the forest 

 area in this unit is bottom land. The red gum- 

 water oak type is almost wholly confined to these 

 bottom-land areas — as is the hackberry-elm-ash 

 type, which is largely a residual type left after the 

 red gum-water oak type has been commercially 

 logged. Where the red gum-water oak type occurs 

 on front lands, the land when cleared is usually 

 valuable for agriculture even without drainage. 

 The overcup oak-bitter pecan type is found on the 

 poorly drained, waxy clay soils of the backwater 

 areas in the bottom land, as well as in shallow 

 sloughs and local basins scattered throughout the 

 bottom land and on the terrace. Even when 

 drained, the soils of this latter type are usually 

 undesirable for agriculture. The cypress-tupelo 

 type is found mainly in deep swamps and on the 

 fertile buckshot soil of deep wet sloughs. 



The cottonwood-willow type is in reality two 

 separate but closely related river-margin types. 

 The two species seldom grow together except in 

 young stands. Cottonwood in pure stands usually 

 grows on high, sandy river margins, or on old fields. 



Forest Types 



The species association in the eight principal 

 forest types as disclosed in the analysis of the field 

 data is given in table 3. The relative importance of 

 each species ^ or species group is expressed as a per- 

 cent of the cubic-foot volume of all species occurring 

 in the type. The areas dominated by six of these 



' Latin names of species mentioned in the text are given 

 on p. 48. 



II 



52142°— .38- 



