occupied by sea ox-eye daisy, saltwort, and poor 

 man's pepper. Several meters further inland helio- 

 trope, frogfruit, and aster grew just above the marsh 

 elevation. 



One important function served by beach plants is 

 the stabilization of sand dunes. As plants grow, they 

 interrupt air flow and cause windborne particles to 

 be deposited. Their roots secure the dunes and help 

 bind loosely-packed sand grains together (Oertel 

 1975). Stabilization of sand dunes as a management 

 practice is widespread, although it is not practiced 

 along the Chenier Plain beaches. A general discussion 

 of dune stabilization practices is, however, included 

 in appendix 6.3. 



4.12.3 CONSUMERS 



In most beach communities, minute detritivores 

 and predators occupy the lower forebeach in the 

 spaces between sand grains. These microbes and small 

 animals (predominantly Crustacea) are supported by 

 organic carbon which filters into sand grains from 

 Gulf waters. Stirring of the beach sediments by the 

 surf insures an adequate oxygen supply for respira- 

 tion. Shore birds, such as plovers, sandpipers, and 

 willets utilize these small animals as a food source. 

 Small fishes consume small crustaceans, as weU as 

 larger benthic macrofauna such as coquinas and other 

 bivalves. 



Reptiles and amphibians are scarce in the beach 

 habitat; only the Gulf coast toad, Woodhouse's toad, 

 and six-lined racerunner are found there. Fish-eating 

 birds, such as the American white pelican, herons, 

 egrets, gulls, and terns are well represented, and there 

 are about 25 species of shorebirds. These birds often 

 concentrate on mudflats during low tides. Some sea- 

 birds nest on remote sections of beach (e.g., laughing 

 gull and least tern), several species of swallows feed 

 in the air over beaches, and other land birds.including 

 grackles and the Savannah sparrow, use the area. Of 

 the birds of prey that may occur on beaches, the 

 osprey and merlin are listed by the National Audubon 

 Society as having declining populations. The en- 

 dangered peregrine falcon also occurs in this habitat 

 during migration. Only three mammals, the Virginia 



opossum, nine-banded armadillo, and Northern rac- 

 coon occur in the beach habitat. A listing of represen- 

 tative vertebrate species which occupy the beach habi- 

 tat is found in appendbc 6.3. 



4.13 RIDGE HABITAT 



Since natural relief in the Chenier Plain is rare, 

 even a relatively low surface feature can be enormously 

 beneficial. Therefore, the importance of the ridge 

 habitat relates to its elevation rather than to its rela- 

 tively small area (table 4.24). 



Cheniers represent the largest and longest of the 

 elevated coastal areas, rising 3 m (10 ft) above mean 

 sea level and extending for many miles. Their orienta- 

 tion is uniformly east and west. Large cheniers are 

 often forested with live oaks. They are used by man 

 for residential and agricultural purposes and serve as 

 avenues for the movement of terrestrial animals into 

 wefland areas. Cheniers and ridges support a rich 

 assortment of plants and animals, and provide roosting 

 and nesting sites for migrating birds. 



Natural stream and man-made levees are generally 

 perpendicular to the coast, while spoil banks are con- 

 structed in all directions. These artificial ridges are 

 much younger and generally smaller than cheniers 

 and are colonized by vines, herbs, willow trees, 

 Chinese tallow trees, and various shrubs. Since these 

 man-made levees and spoil banks are usually con- 

 structed with soils taken from adjacent wetlands or 

 canals, they are liighly organic and shrink and settle 

 with time. If dug in a straight line (as they usually 

 are), canals or borrow pits can affect the surrounding 

 wetlands by draining water and nutrients rapidly into 

 the inland open water habitat. Sometimes canals and 

 barrow pits are dug in a staggered fasliion to allow 

 cattle access to adjacent marshes. 



4.13.1 PRODUCERS 



Cheniers are well above normal tidal influence 

 and support a variety of trees, shrubs, and small plants 

 (table 4.25). Historically, cheniers have supported live 

 oak forests, but many of these forests have been 



Table 4.24. Area (km^ ) of natural and artificial ridge habitat in the Chenier Plain by basin. 



216 



