Incorporation of natural monoacids from plant residues into an hydromorphic forest podzol

Abstract

Summary The monoacid part of soil lipids was studied in a hydromorphic sandy podzol under pine trees ( Pinus maritima sp.). The undecomposed forest‐litter layer (L), the fragmented mycelium‐invaded litter layer (F) and the A1 soil horizon were sampled, and analysed for total lipid and total monoacid contents. Total monoacids were separated into straight‐chain components and terpenic components. Straight‐chain monoacids were determined as free acids and esters of fatty alcohols and of glycerol. Among these components, branched alkanoic acids occurred in the A1 soil horizon. Alkenoic acids were mainly determined as glycerides. Free n‐alkanoic acids were mainly produced in soil from terminal oxidation of plant n‐alkanes and plant n‐alkanols. Free alkanoic acids with the longest carbon chains and alkanoic acids esterified as glycerides were concentrated in the A1 soil horizon. Terpenic monoacids were mainly diterpenic components from pine resin. Their concentration decreased markedly during the decomposition of plant debris.