Effects of pH and plant source on lignocellulose biodegradation rates in two wetland ecosystems, the Okefenokee Swamp and a Georgia salt marsh1,2,3

摘要: The microbial mineralization of synthetic [ L4C]lignin, specifically radiolabeled 14C-ligninl-lignocellulose and L4C-polysaccharide]-lignocellulose from a variety aquatic herbaceous woody plants was investigated in water sediment salt marsh on Sapelo Island, Georgia, the Okefenokee Swamp, an acidic peat-forming freshwater swamp southern Georgia. Rates degradation lignocellulose were depressed relative to those marsh. About 50% difference rates attributable low ambient pH (3.9) (pH 7.1). lignin component only minimally affected within range 4-8, whereas polysaccharide increased severalfold with increasing pH. Differences biodegradability various lignocelluloses also observed; mineralized several times faster than wood. In two large very different detritus-based wetland ecosystems, coastal marshes lie 100 km each other. Due their geographical proximity, environmental conditions such as insolation, rainfall, seasonal temperature regimes do not differ’significantly between ecosystems. Both have dense concentrations macrophytes which are composed primarily structural polymers referred (Hodson et al. 1982, 1983). However, accumulations peat Swamp striking contrast relatively organic content sediments, suggesting major differences transformations fate vascular plant detritus Salt marshes, one at dominated by