FUR-BEARING ANIMALS. At one time the fur industry in Louisiana was 

 a multi-million dollar industry; but, with the gradual disappearance 

 of the muskrat, its value has steadily declined. However, in areas 

 that still have muskrat and suitable habitat, anything more than 

 light to moderate grazing would be detrimental. (Author's introduction 

 and summary) 



Keywords: cattle grazing, marsh fauna, marsh plants, Louisiana 



V-A-8 



Palmisano, A.W., Jr. 1967. Ecological factors affecting occurrence 

 of Scirpus olneyi and Scirpus robustus in the Louisiana coastal 

 marshes. Proceedings of the twenty-first annual conference of the 

 Southeastern Association of Game and Fish Commissioners, pp. 161-172, 



Louisiana contains an estimated 4,000,000 acres of coastal marsh, 

 which provides a livelihood and recreation for thousands of people 

 through fishing, hunting and trapping. This vast area serves as the 

 wintering ground for over 6,000,000 ducks, geese and coots, nearly 

 one-fourth of the total United States waterfowl population. These 

 marshes are also the leading fur-producing habitat in the nation. 

 Over $4,000,000 worth of furs were taken in Louisiana during the 1964- 

 1965 trapping season. This figure, however, is less than half of the 

 value of muskrats ( Ondatra zibethicus ) alone in the 1946-1947 trapping 

 season, when over 8,000,000 muskrat skins worth $8,029,746 were trapped. 

 This decline in muskrat production closely parallels the reduction and 

 deterioration of prime marshlands once dominated by two sedges, 

 three-cornered sedge ( Scirpus olneyi ) and leafy three-cornered sedge 

 ( Scirpus robustus ), long recognized as choice foods for muskrats 

 and blue geese ( Chen caerulescens ) in Louisiana's coastal marshes. 



In the brackish marshes of the state, these important plants are now 

 excluded from vast areas by more competitive species such as couch 

 grass ( Spartina patens ), saltmarsh grass ( Distichlis spicata ) and in 

 some instances big cordgrass ( Spartina cynosuroides ) , all of which 

 tend to form closed stands. The reason or reasons for the inability 

 of the choice sedges to compete successfully with these grasses are 

 not clear. Therefore, this study was undertaken to investigate the 

 basic ecological factors influencing establishment and growth of 

 Scirpus olneyi and Scirpus robustus communities. 



Distribution of S. olneyi was associated with slight depressions in 

 the interior of marshes where minimum water levels ranged from -8.0 

 to +2.0 inches. The maximum soil salinity recorded in these communities 

 was 16,000 ppm and the minimum recorded was 10,100 ppm. The pH of 

 the soil ranged from 4.1 to 6.0. Soil water had higher maximum salinity 

 and pH values than the soil. 



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