proper, levees and dikes may also be seeded or sprigged 

 with vegetation. Both Olney's three-corner grass and 

 saltmarsh bulrush have been seeded and planted in 

 brackish areas to improve the food supply for water- 

 fowl and muskrats (Palmisano and Newsom 1967, 

 Ross 1972). Yellow foxtail, wild millet, Japanese 

 millet, and brown top millet are suitable for seeding 

 in fresh marsh areas for duck food (Neely 1968). 

 Smooth cordgrass is best suited for planting in a salt 

 marsh (Larimore 1968). Levees may be seeded with 

 bermuda grass or sprigged with saltmeadow cord- 

 grass (Soil Conservation Service 1976). 



Method of Preparation. Controlled burning re- 

 moves the thick mat of organic matter to allow easier 

 tilling or disking before planting or seeding. If the 

 planting or seeding project is unsuccessful, the im- 

 pact of burning is increased; without vegetative cover 

 the soil is exposed to wind and tidal erosion, and 

 oxidation. Chemical treatment has been used to 

 destroy undesirable vegetation (Soileau 1968) but it 

 is not an effective means of land preparation for seed- 

 ing or sprigging in the marsh, as chemicals may also 

 destroy or prevent growth of desirable vegetation. 

 The vegetation may be tumed by mechanical tilling. 

 If the marsh is burned, the remaining organic matter 

 may be tilled under the soil surface. TUling is generally 

 a "once over" type of soil break-up, whereas disking 

 requires going over the area several times. Ross (1972) 

 found tilling to be the best means of site preparation 

 for marsh planting projects. 



Water Manipulation. Levees, weirs, impound- 

 ments, and pumps may be used prior to planting or 

 seeding to (1) provide an optimum water level for 

 plant growth, (2) eliminate undesirable species, (3) re- 

 tain water in ponds and channels for aquatic vegeta- 

 tion, (4) allow better seed germination, (5) drain an 

 area for tilling and disking, or burning, and (6) drain 

 an area to oxidize bottom sediments and firm them 

 up to provide a better surface for plant attachment. 

 Water manipulation greatly affects the success and 

 impact of a planting or seeding project. All vegetation 

 has an optimum range of salinity and water level. If 

 this range can be met through water manipulation, 

 the chances of success are increased. 



Suitability of the Species. Planting and seeding 

 projects are usually done to provide a food source for 

 ducks, geese, or muskrats; and this determines the 

 species of vegetation to be planted. The species must 

 also be suited to the environment in which it is 

 planted, especially with reference to salinity and water 

 levels, and must be able to compete successfuUy with 

 natural vegetation and other invader species. Plantings 

 may fail because of competition from animals. 



Excessive grazing of young grass shoots by cattle, 

 geese, or muskrats, called an "eat-out," will destroy 

 the vegetation or reduce its capacity to revegetate. 

 Birds frequently eat the seeds before they germinate. 



4.7.8 CATTLE GRAZING 



To realize an economic return from wetlands, 

 cattle are allowed to graze some two million acres of 



coastal marsh (Williams 1955). Grazing may occur 

 year-round; however, mosquitoes and the chance of 

 floods reduce this practice during the period from 

 May to September. 



Both fresh and salt marsh are grazed. Maidencane 

 and southern wild rice are preferred forage in fresh 

 marsh areas; the Spartina species, seashore paspalum, 

 and sahgrass are grazed in the salt marsh. 



Grazing in the marsh depends on the number and 

 distribution of ridges. Cattle will graze up to one 

 quarter mOe from a ridge or levee (Williams 1952), 

 and this area becomes severely overgrazed. Cattle 

 walkways, or artificial ridges, placed 0.8 km (0.5 mi) 

 apart allow grazing to be more evenly distributed. 

 Cattle walkways are also used for bedding grounds, 

 supplemental feeding, and retreats in case of high 

 water. 



Walkways are characteristic of the Chenier Plain, 

 which has some 390 km (242 mi) of walkways (Soil 

 Conservation Service estimate, unpubhshed), while 

 the Mississippi Deltaic Plain, to the east, has only 

 16 km (10 mi) of walkways because natural delta 

 marsh soils generally will not support the weight of 

 cattle. 



Environmental Impacts of Cattle Grazing. The im- 

 pact of cattle grazing depends upon grazing pressure, 

 the condition of the marsh range, the suitability of 

 soils, the time of the year the marsh is grazed, and the 

 use of cattle walkways. The foDowing stocking rates 

 on salt and fresh marsh ranges are recommended by 

 the Soil Conservation Service: 



Marsh in 



climax 



vegetation % 



Salt marsh 



mid fall- 



late spring 



Fresh marsh 

 late winter- 

 mid-suramer 



75 to 100 1.6 ha(4 a)/cow 1.2 ha (3 a)/cow 



50 to 75 2.4 ha (6 a)/cow 1.6 ha (4 a)/cow 



25 to 50 3.2 ha (8 a)/cow 2.4 ha (6 a)/cow 



to 25 4.8 ha(12a)/cow 4.0 ha (10 a)/cow 



Chabreck (1968a) has identified three range 

 types: high marsh consisting of firm, well-drained 

 soils used as bedding ground; intermediate marsh con- 

 sisting of fairly firm soil with slower drainage after 

 rains; and low soft, poorly drained marsh normally 

 covered with water that is several inches deep into 

 which cattle sink up to eight inches. Cattle spend 

 50% of their time on high marsh, 30% on interme- 

 diate, and 20% on low marsh. Range types in the 

 Chenier Plain marsh are mainly high and intermediate. 

 In the low marsh the hooves of cattle destroy vegeta- 

 tion that may take several months to recover (Cha- 

 breck 1968a). 



Intensity, and time of year of grazing, are both 

 important to marsh utilization by wildlife resources. 

 Light or moderate grazing removes dense stands of 

 mature vegetation and encourages the growth of 

 Scirpus sp., a preferred duck food (Chabreck 1968a). 

 Tender, new grass growth resulting from moderate 

 grazing, also benefits snow geese. Invader species that 



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