cleared to produce pasture and farmland. On the 

 more heavily grazed cheniers, the vegetation consists 

 primarily of chickasaw plum, prickly pear cactus, and 

 salt cedar (Palmisano 1967). 



Table 4.25. Natural vegetation of the cheniers in the 

 Louisiana portion of the Chenier Plain 

 (Palmisano 1967, 1970). 



Common name 



Trees 

 Live oak 

 Hackberry 

 American elm 

 Drummond red maple 

 Baldcypress 

 Water locust 

 Prickly ash 

 Persimmon 

 Water oak 



Understory 

 Palmetto 

 Blackberry 

 Haws 



Buttonbush 

 Deciduous holly 

 Chickasaw plum 

 Groundsel tree 

 Saltmeadow cordgrass 

 Grape 



Black willow 

 Salt cedar 

 Prickly pear cactus 



Plant communities on man-made levees and spoil 

 banks include a wide range of species, many of which 

 are primary invaders on disturbed sites. The most 

 common plants include marsh elder, groundsel tree, 

 bermuda grass, saltmeadow cordgrass, saltgrass, 

 common reed, and blackberry, and the overstory 

 trees, willow and Chinese tallow. On Rockefeller 

 Wildlife Refuge, Spindler and Noble (1974) found 

 that groundsel tree and saltmeadow cordgrass were 

 dominant on spoil banks, while saltmeadow cordgrass, 

 bulltongue, giant bulrush, sawgrass, common reed, 

 and Walter's millet were prevalent in adjacent wet- 

 lands. 



On th.se elevated areas the composition of her- 

 baceous and shrubby vegetation reflects the salinity 

 of the spoil. As salts are leached from spoil sediments, 

 trees invade and plant communities change. Even- 

 tually, there is a convergence toward the climax com- 

 munity of old cheniers. 



4.13.2 CONSUMERS 



The ridge habitat, as defined, includes not only 

 forested cheniers, but spoil banks and natural and 

 man-made levees in all stages of succession. The physi- 

 cal diversity of this habitat type is reflected by a high 

 species richness (appendix 6.3). The ridge habitat is 

 not only inhabited by species typical of forest or 

 shrub associations but also by marsh species which 

 use elevated areas for nesting, basking, or other activi- 

 ties. Spoil bank areas would be expected to support 

 fewer animal species than would cheniers, because 

 they are less diverse vegetatively and are more exposed 

 to flooding. 



Populations of various terrestrial salamanders, 

 toads, and treefrogs occur in the ridge habitat. 

 Reptiles including box turtles, lizards such as the sLx- 

 Uned racerunner and Eumeces skinks, the prairie 

 kingsnake, the rough earth snake, and the pygmy 

 rattlesnake are all characteristic of upland habitats. 

 However, the alligator and a variety of aquatic turtles 

 and snakes move from inland lakes and wetland habi- 

 tats onto ridges, levees, and spoil banks to nest, bask, 

 and hibernate. 



Bird species richness is greater for the ridge habi- 

 tat than for other habitat types in terms of summer 

 residents, year-round residents, and migratory 

 transients. The relatively high number of breeding 

 birds (summer and year-round residents) may be 

 related to the heterogeneity of the ridge habitat. 

 Ridges are often the only forested islands in a sea of 

 wetlands and they provide nesting sites for typical 

 forest birds, as well as for birds from marsh or agri- 

 cultural habitats. Some beach-inhabiting species may 

 also fmd suitable nesting sites on new spoil banks. 

 Wading bird rookeries are often located on forested 

 cheniers or old levee sites. 



Typical terrestrial mammals that occur on Chenier 

 Plain ridges include the white-tailed deer. Northern 

 raccoon, swamp rabbit, least shrew, nine-banded 

 armadillo, gray and fox squirrels, marsh rice rat, 

 cotton mouse, eastern wood rat, coyote, gray fox, 

 and bobcat. 



Use of ridge habitats by migrating birds. More 

 than 60 species of land birds that spend the winter 

 months in Central and South America return to 

 North America in spring by flying directly across the 

 Gulf of Mexico (Lowery 1945, 1951). These species 

 are listed in appendbc 6.3. 



The spring migration period in coastal Louisiana 

 extends from late March to mid-May (Hebrard 1971). 

 Trans-gulf flights occur somewhat erratically in March 

 and then on a regular, almost daily basis from the 

 first week in April through the second week in May. 

 Each species has its own seasonal pattern. Birds that 

 nest in southern Louisiana generally appear first in 

 the spring, followed by those species that nest in 

 more northern latitudes. 



Most of these birds are nocturnal migrants, 

 generally migrating all night and feeding during the 

 day. This is illustrated in the temporal pattern of 



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