title: Changes in lignin content of leaf litters during mulching.
abstract: Alkaline nitrobenzene oxidation, ozonation and methoxyl content determinations were applied to decomposing leaf litter of Ginkgo biloba L., Cinnamomum camphora sieb., Zelkova serrata Makino and Firmiana simplex W. F. Wight, respectively, during mulching to investigate the properties and estimate changes in lignin composition and content. Since the Klason lignin residue originated from components highly resistant to degradation by acid, the methoxyl content of Klason residue was used to estimate the lignin content of leaf litter. Quantitative analysis of presumed lignin-derived fragments, by use of alkaline nitrobenzene oxidation and ozonation methods, suggested that the estimated lignin content approximates that of the real lignin content of leaves, which is greatly overestimated by the Klason procedure. The estimated lignin contents ranged from 3.9 to 10.0% while the Klason lignan residue varied from 37.1 to 46.7% in un-mulched leaf litter. The absolute amounts of the measured lignin somewhat decreased during mulching, while the structure of lignin remaining in leaf litters after mulching was considered not to be very different from its original structure.
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Zhenfu
authors.initials: Z
authors.lastname: Jin
authors.forename: Takuya
authors.initials: T
authors.lastname: Akiyama
authors.forename: Byung Yeoup
authors.initials: BY
authors.lastname: Chung
authors.forename: Yuji
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Kenji
authors.initials: K
authors.lastname: Iiyama
authors.forename: Satomi
authors.initials: S
authors.lastname: Watanabe
mesh_terms: D000383:Agriculture / Q000379:methods*; D018533:Biomass; D027423:Cinnamomum camphora / Q000737:chemistry; D020441:Ginkgo biloba / Q000737:chemistry; D008031:Lignin / Q000032:analysis* / Q000737:chemistry*; D019660:Malvaceae / Q000737:chemistry; D009578:Nitrobenzenes / Q000737:chemistry; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry*; D034401:Ulmaceae / Q000737:chemistry
chemical_list: D009578:Nitrobenzenes; D010126:Ozone; D008031:Lignin