Interactive effects of elevated CO2 and nitrogen deposition on fatty acid molecular and isotope composition of above- and belowground tree biomass and forest soil fractions

© 2014 John Wiley & Sons Ltd.

Bibliographische Detailangaben
Veröffentlicht in:Global change biology. - 1999. - 21(2015), 1 vom: 31. Jan., Seite 473-86
1. Verfasser: Griepentrog, Marco (VerfasserIn)
Weitere Verfasser: Eglinton, Timothy I, Hagedorn, Frank, Schmidt, Michael W I, Wiesenberg, Guido L B
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2015
Zugriff auf das übergeordnete Werk:Global change biology
Schlagworte:Journal Article Research Support, Non-U.S. Gov't biogeochemistry biomarkers compound-specific stable isotope analysis fatty acids plant biomass soil density fractionation soil organic matter Carbon Isotopes mehr... Fatty Acids Reactive Nitrogen Species Soil Carbon Dioxide 142M471B3J
Beschreibung
Zusammenfassung:© 2014 John Wiley & Sons Ltd.
Atmospheric carbon dioxide (CO2) and reactive nitrogen (N) concentrations have been increasing due to human activities and impact the global carbon (C) cycle by affecting plant photosynthesis and decomposition processes in soil. Large amounts of C are stored in plants and soils, but the mechanisms behind the stabilization of plant- and microbial-derived organic matter (OM) in soils are still under debate and it is not clear how N deposition affects soil OM dynamics. Here, we studied the effects of 4 years of elevated (13C-depleted) CO2 and N deposition in forest ecosystems established in open-top chambers on composition and turnover of fatty acids (FAs) in plants and soils. FAs served as biomarkers for plant- and microbial-derived OM in soil density fractions. We analyzed above- and belowground plant biomass of beech and spruce trees as well as soil density fractions for the total organic C and FA molecular and isotope (δ13C) composition. FAs did not accumulate relative to total organic C in fine mineral fractions, showing that FAs are not effectively stabilized by association with soil minerals. The δ13C values of FAs in plant biomass increased under high N deposition. However, the N effect was only apparent under elevated CO2 suggesting a N limitation of the system. In soil fractions, only isotope compositions of short-chain FAs (C16+18) were affected. Fractions of 'new' (experimental-derived) FAs were calculated using isotope depletion in elevated CO2 plots and decreased from free light to fine mineral fractions. 'New' FAs were higher in short-chain compared to long-chain FAs (C20-30), indicating a faster turnover of short-chain compared to long-chain FAs. Increased N deposition did not significantly affect the quantity of 'new' FAs in soil fractions, but showed a tendency of increased amounts of 'old' (pre-experimental) C suggesting that decomposition of 'old' C is retarded by high N inputs
Beschreibung:Date Completed 10.08.2015
Date Revised 16.11.2017
published: Print-Electronic
Citation Status MEDLINE
ISSN:1365-2486
DOI:10.1111/gcb.12666