The relative importance of exogenous and substrate-derived nitrogen for microbial growth during leaf decomposition

Simple item page
dc.contributor.authorCheever, B. M.en
dc.contributor.authorWebster, Jackson R.en
dc.contributor.authorBilger, E. E.en
dc.contributor.authorThomas, S. A.en
dc.contributor.departmentBiological Sciencesen
dc.date.accessed2014-03-11en
dc.date.accessioned2014-03-27T13:05:59Zen
dc.date.available2014-03-27T13:05:59Zen
dc.date.issued2013-07en
dc.description.abstractHeterotrophic microbes colonizing detritus obtain nitrogen (N) for growth by assimilating N from their substrate or immobilizing exogenous inorganic N. Microbial use of these two pools has different implications for N cycling and organic matter decomposition in the face of the global increase in biologically available N. We used sugar maple leaves labeled with N-15 to differentiate between microbial N that had been assimilated from the leaf substrate (enriched with N-15) or immobilized from the water (natural abundance N-15:N-14) in five Appalachian streams ranging in ambient NO3-N concentrations from about 5 to 900 g NO3-N/L. Ambient NO3- concentration increased sugar maple decomposition rate but did not influence the proportion of microbial N derived from substrate or exogenous pools. Instead, these proportions were strongly influenced by the percentage of detrital ash-free dry mass (AFDM) remaining. Substrate-derived N made up a large proportion of the microbial N after the first 24 h in all streams. Detrital and microbial isotopic N-15 signatures approached that of the water as decomposition progressed in all streams, suggesting that exogenous N may be the predominant source of N for meeting microbial requirements even when exogenous N concentrations are low. Our results support predictions of more rapid decomposition of organic matter in response to increased N availability and highlight the tight coupling of processes driving microbial N cycling and organic matter decomposition.en
dc.description.sponsorshipNSF DEB-0823293, DEB-02218001, DEB-478406en
dc.identifier.citationB. M. Cheever, J. R. Webster, E. E. Bilger, and S. A. Thomas 2013. The relative importance of exogenous and substrate-derived nitrogen for microbial growth during leaf decomposition. Ecology 94:1614-1625. http://dx.doi.org/10.1890/12-1339.1en
dc.identifier.doihttps://doi.org/10.1890/12-1339.1en
dc.identifier.issn0012-9658en
dc.identifier.urihttp://hdl.handle.net/10919/46815en
dc.identifier.urlhttp://www.esajournals.org/doi/pdf/10.1890/12-1339.1en
dc.language.isoen_USen
dc.publisherEcological Society of Americaen
dc.rightsIn Copyrighten
dc.rights.holderEcological Society of Americaen
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectn-15en
dc.subjectassimilationen
dc.subjectchloroform fumigationen
dc.subjectheterotrophic microbesen
dc.subjectimmobilizationen
dc.subjectnitrogen availabilityen
dc.subjectnitrogen cyclingen
dc.subjectorganic matteren
dc.subjectdecompositionen
dc.subjectstreamsen
dc.subjectforest litter decompositionen
dc.subjectsoil-nitrogenen
dc.subjectwoodland streamen
dc.subjectchloroformen
dc.subjectfumigationen
dc.subjectphosphorus dynamicsen
dc.subjectfoliar litteren
dc.subjectnutrienten
dc.subjectcarbonen
dc.subjectreleaseen
dc.subjectligninen
dc.titleThe relative importance of exogenous and substrate-derived nitrogen for microbial growth during leaf decompositionen
dc.title.serialEcologyen
dc.typeArticle - Refereeden
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
12-1339%2E1.pdf
Size:
557.68 KB
Format:
Adobe Portable Document Format
Description:
Main article
Download
Collections
Scholarly Works, Biological Sciences