ABSTRACT
Initial efforts to relate fungal activity during the decomposition of plant litters in aquatic and salt marsh systems to the nutrient and carbon budgets are reviewed by Gessner et al. (1997). They showed that fungal biomass increases at an early stage of the decomposition of the plant material and forms a significant proportion of the total detrital mass (up to 15%). The effects of fungal and bacterial action on the carbon flux in decomposing plant residues in aquatic and marine systems is given in Fig. 2.8, in which the rate of decomposition is greatest in salt marshes and the importance of a high mycelial biomass is highest. Concomitant to a faster decomposition rate of Spartina than Plantanus, a higher percentage of the carbon is released as dissolved and fine particulate organic matter from Spartina. The effect that these end products have on nutrient dynamics and the support of primary and secondary productivity within the ecosystem is as yet unknown. Regulation of fungal degradation of plant residues in aquatic and salt marsh ecosystems are positively enhanced by increased fungal biomass, which is reflected in the production of conidia, and activity (measures of adenosine triphosphate ATP activity). As in the terrestrial ecosystem, the high lignin content of the resource reduces its rate of decomposition, which can be ameliorated by the exogenous supply of nitrate nitrogen in the system, (Gessner et al., 1997).
