title: Phytotoxicity, not nitrogen immobilization, explains plant litter inhibitory effects: evidence from solid-state 13C NMR spectroscopy.
abstract: Litter decomposition provides nutrients that sustain ecosystem productivity, but litter may also hamper root proliferation. The objectives of this work were to assess the inhibitory effect of litter decomposition on seedling growth and root proliferation; to study the role of nutrient immobilization and phytotoxicity; and to characterize decomposing litter by (13)C NMR spectroscopy. A litter-bag experiment was carried out for 180 d with 16 litter types. Litter inhibitory effects were assessed by two bioassays: seed germination and root proliferation bioassays. Activated carbon (C) and nutrient solutions were used to evaluate the effects of phytotoxic factors and nutrient immobilization. An inhibitory effect was found for all species in the early phase of decomposition, followed by a decrease over time. The addition of activated C to litter removed this inhibition. No evidence of nutrient immobilization was found in the analysis of nitrogen dynamics. NMR revealed consistent chemical changes during decomposition, with a decrease in O-alkyl and an increase in alkyl and methoxyl C. Significant correlations were found among inhibitory effects, the litter decay rate and indices derived from NMR. The results show that it is possible to predict litter inhibitory effects across a range of litter types on the basis of their chemical composition.
authors.affiliation: Dipartimento di Arboricoltura, Botanica e Patologia Vegetale, University of Naples Federico II, via Università 100, 80055 Portici (NA), Italy.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Bonanomi
authors.affiliation: Dipartimento di Scienze della Vita, University of Trieste, via Giorgieri 10, 34127 Trieste, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Incerti
authors.affiliation: Burnham Institute for Medical Research, North Torrey Pines, 92037 San Diego, CA, USA.
authors.forename: Elisa
authors.initials: E
authors.lastname: Barile
authors.affiliation: Dipartimento di Arboricoltura, Botanica e Patologia Vegetale, University of Naples Federico II, via Università 100, 80055 Portici (NA), Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Capodilupo
authors.affiliation: Dipartimento di Arboricoltura, Botanica e Patologia Vegetale, University of Naples Federico II, via Università 100, 80055 Portici (NA), Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Antignani
authors.affiliation: Dipartimento di Arboricoltura, Botanica e Patologia Vegetale, University of Naples Federico II, via Università 100, 80055 Portici (NA), Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Mingo
authors.affiliation: Dipartimento di Scienza degli Alimenti, University of Naples Federico II, via Università 100, 80055 Portici (NA), Italy.
authors.forename: Virginia
authors.initials: V
authors.lastname: Lanzotti
authors.affiliation: Dipartimento di Arboricoltura, Botanica e Patologia Vegetale, University of Naples Federico II, via Università 100, 80055 Portici (NA), Italy.
authors.forename: Felice
authors.initials: F
authors.lastname: Scala
authors.affiliation: Dipartimento di Arboricoltura, Botanica e Patologia Vegetale, University of Naples Federico II, via Università 100, 80055 Portici (NA), Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Mazzoleni
mesh_terms: D001692:Biological Transport; D002244:Carbon / Q000378:metabolism; D002247:Carbon Isotopes / Q000032:analysis; D018525:Germination; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D009584:Nitrogen / Q000378:metabolism*; D063245:Plant Development; D018515:Plant Leaves / Q000737:chemistry*; D018517:Plant Roots / Q000254:growth & development*; D010944:Plants / Q000737:chemistry*; D036226:Seedlings / Q000254:growth & development*; D012639:Seeds / Q000254:growth & development / Q000378:metabolism; D012987:Soil / Q000737:chemistry
chemical_list: D002247:Carbon Isotopes; D012987:Soil; D002244:Carbon; D009584:Nitrogen