UPLAND FORESTS (19) 



Upland forests occur on the Pleis- 

 tocene Terrace north of Lake Pontchar- 

 train, in Mississippi, and on a series 

 of narrow natural levee ridges that 

 extend as peninsulas into wetland areas 

 (Figure 38) . This habitat occupies 

 about 71,000 ha (175,000 acres) of the 

 MDPR in 1978, or 2.02% of the region 

 (Table 5) . 



Upland forest habitat was formerly 

 much greater, occupying most of the 

 natural levees. The upland forest hab- 

 itat has probably been more drastically 

 reduced, in a relative sense, in the 

 MDPR than any other natural habitat. 

 Most of this area has been developed for 

 agriculture and urban-industrial use 

 because it is the most elevated land in 

 a region in which development has often 

 been limited by high land. 



Upland forest habitat grades into 

 bottomland hardwood as elevation de- 

 clines and flooding frequency increases 

 on the lateral slopes of the natural 

 levee ridges. Bottomland hardwood hab- 

 itat in turn grades into swamp forest 

 habitat with further decline in eleva- 

 tion toward the interdistributary 

 basins. This gradual change is illus- 

 trated in Figure 39, which shows the 

 spectrum of flood tolerance of various 

 trees . 



The natural levee ridges on which 

 the remaining upland forest habitat is 

 found are composed of Mississippi River 

 alluvial soils. The higher soils are 

 characteristically silty loams, which 

 are well oxygenated. At lower elevation 

 the soils are more clayey and firm when 

 moist (Monte 1978) . The maximum eleva- 

 tion of the natural levee ridges in the 

 MDPR is less than 6 m above sea level, 

 and most levee areas are less than 3 m 

 (Monte 1978) . 



Natural climax vegetation on well- 

 drained and undeveloped Pleistocene 

 Terrace sites is dominated by mixed 

 deciduous and evergreen trees that are 

 less tolerant to flooding than are many 

 bottomland hardwood species. These 

 include oaks (Que reus virginiana , ^. 



alba , Q. nigra ) , shagbark hickory ( Carya 

 ovata ) , hackberry ( Celtis laevigata ) , 

 sweetgum ( Liquidambar styraclf lua ) , 

 pecan ( Carya illinoensis ) , magnolia 

 ( Magnolia sp.), and various pines. Some 

 of the pine woodlands are now cultivated 

 for lumber and pulpwood. 



Ridges supporting upland vegeta- 

 tion are prominent in marsh zones 

 because they support woody vegetation 

 and they are often visibly dominated by 

 mature (sometimes stunted and dying) 

 live oak trees. Natural levees serve as 

 homes and migration routes for some ter- 

 restrial animals that may venture into 

 the marsh for food during low water. 

 During very high tides and storm surges, 

 the levee ridges may be the only exposed 

 land, and they can become densely popu- 

 lated. 



From prehistoric times until the 

 present, natural levees have also pro- 

 vided human beings with the only firm 

 living and transportation space avail- 

 able. The cultural pressure on natural 

 levee ridges is intense, and undisturbed 

 natural levee habitat is scarce. Natural 

 levee ridge habitat includes all the old 

 Mississippi River distributary ridges, 

 such as the Bayou Lafourche ridge, the 

 Metairie-New Orleans ridge and the old 

 Bayou Teche ridge, upon which Morgan 

 City is located. 



The Caminada ridges in the lower 

 Barataria hydrologic unit are not natu- 

 ral levees, but stranded beach ridges 

 (cheniers) parallel to the coast line. 

 Such ridges also occur in Southern 

 Hancock County, Mississippi (Otvos 

 1981). 



URBAN-INDUSTRIAL (20) 



The urban-industrial system is not 

 often thought of as a habitat, since 

 human settlements have acquired the 

 connotations of artificial and even un- 

 natural environments. Humans and their 

 artifacts are, however, constrained by 

 many of the same factors that limit 

 other forms of life. Thus this study 

 treated the habitat in which human 

 beings live and work as analogously as 



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