4.14.3 CONSUMERS 



4.15 AGRICULTURAL HABITATS 



Vertebrate species composition in the upland 

 forest habitat is similar to that of the swamp forest 

 habitat, with the omission of most aquatic or semi- 

 aquatic forms. Eleven species of amphibians include 

 terrestrial salamanders and arboreal frogs, as well as 

 terrestrial frogs and toads. There are fewer species 

 of reptiles here than in the swamp forest habitat. 

 A variety of birds, including raptors and song birds, 

 occur in the upland forest habitat. Mammals found 

 in the upland forest habitat are similar to those found 

 in the swamp forest habitat, except for the absence 

 of aquatic furbearers such as the nutria, otter, and 

 muskrat. Lists of representative vertebrates found in 

 the upland forest habitat are found in appendix 6.3. 



The loblolly pine-shortleaf pine type forest 

 usually supports a limited white-tailed deer popula- 

 tion, moderate squirrel populations, and low numbers 

 of bobwhite quaU (Parker et al. 1975). However, cer- 

 tain areas where the number of hardwoods is signifi- 

 cant can support increased numbers of deer and 

 squirrels. 



The upland forest habitat supports a large 

 number of insect species. Several of these, including 

 the southern pine beetle, Ips engraver beetle, hickory 

 bark beetle, and various oak borers,cause considerable 

 damage. 



4.14.4 IMPACTS OF FORESTRY PRACTICES 



In upland forests along the Gulf coastal plain, 

 mechanized site preparation practices pose a threat to 

 soil and water quality (McClurkin and Duffy 1975). 

 Even though data are scarce, logging experience and 

 agricultural engineering show that the use of heavy 

 equipment in these practices compacts and destroys 

 forest soil structure. This reduces the amount of 

 infiltration of water and increases surface runoff. 

 Exposed soils are subject to increased erosion. Where 

 large volumes of fresh organic matter are incorporated 

 into the soil, as through clearcutting, there is a drastic 

 increase in the carbohydrate to nitrogen ratio. Acids 

 released during decomposition of this excess material 

 leach nutrients from the soil. Since Uttle biomass is 

 left after clearcutting to take up these nutrients, they 

 may substantially change the water quality of nearby 

 streams (McClurkin and Duffy 1975). 



Of all forestry practices, fertilization has the 

 greatest potential for causing changes in water quahty. 

 If fertilizers are not taken up by the existing vegeta- 

 tion, they may leak into shallow ground-water aqui- 

 fers, drainage ditches, or streams. Eutrophic con- 

 ditions result when fertilizers accumulate in ponds or 

 in downstream wetlands. 



Grazing may significantly modify the upland 

 forest habitat. Cattle destroy young seedlings, and 

 heavily grazed areas are subject to extreme erosion 

 along cattle trails and where herbs and grasses have 

 been overcropped. 



Rice fields and pastures, the dominant agri- 

 cultural habitats in the Chenier Plain, make up about 

 16% of the area (fig. 446). The extent of these habi- 

 tats varies from 3.6% in the Chenier Basin to more 

 than 20% in East Bay and Mermentau basins. Rice 

 fields and pastures have slowly and steadily increased 

 at the expense of natural areas. 



The relative proportion of rice fields to pasture- 

 lands varies widely from year to year as market con- 

 ditions fluctuate and crops are rotated for optimum 

 production. The most common practice is to plant 

 half the farm with rice and use the other half as 

 pasture for beef cattle. A preferred practice is to graze 

 the land for 2 to 4 years before replanting rice. This 

 rotation of rice and cattle increases the organic matter 

 in the soil, the available nitrogen, and other plant 

 nutrients (Black and Walker 1955). 



Agricultural systems differ considerably from 

 natural systems for the following reasons: 



1. Agriculture requires large fossil fuel inputs 

 for cultivation, fertilization, water level 

 regulation, harvesting, and curing. 



2. Agricultural habitats are necessarily highly 

 simplified; most producers and consumers 

 are eliminated in favor of selected organisms. 



Eutrophic and toxic effects result when fertilizers 

 and pesticides enter natural water bodies and wet- 

 lands. Some pesticides or their products can remain 

 in these habitats for years. For example, the fire ant 

 poison Mirex, appHed to a Mississippi experimental 

 plot at 1.0 lb/a in 1962, was still present in 1974 at a 

 level of one part per million (Carlson et al. 1976). 



Agricultural habitats, on the other hand, can 

 benefit some wildUfe species (especially waterfowl) 

 by providing alternative food sources. This benefit 

 becomes increasingly important as natural areas 

 are reduced. 



4.15.1 FUNCTIONAL OVERVIEW OF AGRICUL- 

 TURAL HABITATS 



The basic components and functions of the agri- 

 cultural habitats in the Chenier Plain are illustrated in 

 fig. 4-47. Rice field and pasture habitats are readily 

 interchangeable. The major agricultural producers, 

 rice plants and pasture grasses, are dependent upon 

 sunlight, but production levels are dependent on 

 cultivation and harvest techniques, fertilizer and 

 pesticide apphcations, and the availability of fossO 

 fuels to operate machinery. Plants are used to feed 

 cattle or are harvested for human consumption. In 

 addition, both habitats are used by a variety of 

 mammals, birds, reptiles, amphibians,and crustaceans. 

 Crayfish cultivation is sometimes practiced along with 

 rice production. Both rice fields and pastures are sub- 

 ject to runoff of rainwater which can carry with it 

 significant levels of nutrients and/or toxins. 



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