title: Exposure of wood in floodplains affects its chemical quality and its subsequent breakdown in streams.
abstract: In stream ecosystems, coarse organic matter from the riparian vegetation, a key food resource, is often retained in the floodplains before reaching the channel. During floodplain exposure, organic matter can be affected by abiotic and biotic processes ("preconditioning"), which alter its quality and affect its subsequent decomposition in streams. We analyzed the effect of floodplain preconditioning on wood quality (lignin, C, N, P, K, among others), and its subsequent aquatic breakdown, paying special attention to microbial activity. We simulated preconditioned standard wooden sticks on one arid stream floodplain for 3 and 4 months, and then monitored their breakdown in three different streams, together with control (non-preconditioned) sticks. Preconditioning reduced lignin mass and C:N and lignin:N ratios, caused the leaching of soluble nutrients such as P and K, as well as N immobilization by microbes. These changes enhanced the breakdown of wood in the first week of immersion, but had no effect on breakdown rates after 4 months of incubation in the streams, although N immobilization was diminished. Our results suggest that terrestrial preconditioning could alter the role of wood as a long-lasting nutrients and energy source for freshwater ecosystem.
authors.affiliation: Department of Ecology and Hydrology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Campus de Espinardo, 30100 Murcia, Spain. Electronic address: rubendel.campo@um.es.
authors.forename: Rubén
authors.initials: R
authors.lastname: Del Campo
authors.affiliation: Department of Ecology and Hydrology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Campus de Espinardo, 30100 Murcia, Spain.
authors.forename: Rosa
authors.initials: R
authors.lastname: Gómez
mesh_terms: D001673:Biodegradation, Environmental; D017753:Ecosystem; D004784:Environmental Monitoring; D018515:Plant Leaves; D045483:Rivers / Q000737:chemistry*; D014934:Wood / Q000032:analysis / Q000737:chemistry*
keywords: Abiotic factors; C processing; Floods; Microbial activity; Terrestrial decomposition; Wood