Silica in Relation to Leaf Decomposition of Juncus roemerianus

Abstract

Silica content was examined in relation to the age of living and dead-standing leaves of the intertidal rush, Juncus roemerianus. The percentage of silica increases as the leaf decomposes, the leaves ranging from one to eight years of age. Saprophytic fungi are the primary decomposition organisms. As the cellulose cell walls of the structural and supportive tissues come under attack, the fungal mycellium increases within the leaf. This is directly indicated by an increase in ash content as the leaf dry mass weight approaches zero. Dead-standing leaves at eight years of age are essentially a siliceous cast of the leaf. This study suggests an alternative view to the decomposition process of Juncus roemerianus and estuarine energetics.