Lignocellulose and lignin in the salt marsh grass Spartina alterniflora: initial concentrations and short-term, post-depositional changes in detrital matter

Abstract

Lignocellulose was found to comprise the bulk of various anatomical structures of the salt marsh grass Spartina alterniflora, as well as of detritus derived from this plant; although concentrations of both lignin and lignocellulose varied with plant height-form, age, and anatomical structure. Changes in the relative concentrations of lignin and polysaccharide in lignocellulose due to long-term degradation by natural marsh microflora were determined using standard gravimetric assay procedures and a new procedure utilizing specifically-radiolabelled 14C-(cellulose)-lignocellulose and 14C-(lignin)-lignocellulose prepared from S. alterniflora. Results obtained with the two methods agreed, thus validating the new procedures. Mineralization of the cellulose moiety was more rapid than mineralization of the lignin moiety resulting in relative enrichment of S. alterniflora detritus in lignin. Rates of mineralization of both moieties decreased over time such that extent of mineralization was a function of the logarithm of aging time.