by intense microbial activity resulting ultimately in establishment 

 of a distinctive rhizosphere microflora. The microbial equilibrium 

 of the soil is affected by the growing plant. Superimposed on the root 

 effect are the multitude of associative and antagonistic reactions 

 among the microorganisms themselves. 



Author-related mycological studies in the South Florida and Everglades 

 region, the North Sea, and Lake Champlain have suggested that yeast 

 populations in these locales may be interpreted from aspects of both 

 "standing crop" and "bloom" development. Investigations reported in 

 this paper on yeasts of the Louisiana marshland support these observa- 

 tions. It is hoped that analysis of microbial successional patterns 

 will provide information on fluctuations in microbial populations 

 associated with plant growth, ability of yeasts to compete with bacteria 

 for available nutrients, and the nature of yeast physiological ecology. 

 The predominant marshland yeast population is cellobiose-utilizing and 

 must be able to compete with the bacteria present for this carbohydrate. 

 In view of the inability of yeasts to degrade cellulose, their role In 

 the Spartina biodegradation probably involves mainly utilization of 

 products resulting from a primary attack on the plant matter by other 

 organisms. Further development of studies on the total cellulolytic 

 biomass (both bacteria and fungi) in the Spartina habitat will provide 

 essential information on the rate of turnover of plant substrate and 

 release of nutrients for microbial activities. The complexity of 

 microbial relationships in degradation of submerged cellulosic 

 substrates will require detailed investigation of the biology of the 

 organisms involved. (G.S.) 



Keywords: mycology, biodegradation, oyster grass, Spartina alterni flora , 

 coastal marshes, Louisiana 



III-C-6 



Cowley, G.T. 1973. Variations in soil fungus populations in a South 



Carolina salt marsh. Pages 441-454 i_n L.H. Stevenson and R.R. Colwell, 

 eds., Estuarine microbial ecology. University of South Carolina Press, 

 Columbia. 



Since the publication of research during the 1930s on the fungi 

 of the Dovey salt marsh soils, little new data have appeared 

 in the literature which would contribute to the understanding of 

 salt marsh soil fungus populations. The work done to date has 

 concentrated primarily on taxonomy of isolates rather than population 

 structure. This study was an attempt to assess variations in soil 

 fungus populations and to prepare the groundwork for further studies 

 on the evaluation of the effects of environmental variables. The role 

 of saprophytic fungi in salt marsh soil environments was considered. 

 Although many salt marshes are available for study in South Carolina, 

 the Hobcaw Barony salt marsh near Georgetown, South Carolina, was 

 selected because it is apparently less influenced by domestic and 



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