Journal Article

PreJuSER-111945

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Stable carbon isotope analysis of fluvial sediment fluxes over two contrasting C4-C3 semi-arid vegetation transitions

Puttock, A. ; Dungait, J. A. J. ; Bol, R.FZJ* ; Dixon, E. R. ; Macleod, C. J. A. ; Brazier, R. E.

2012
Wiley Interscience New York, NY

This record in other databases:      

Please use a persistent id in citations: doi:10.1002/rcm.6257

Abstract: Globally, many drylands are experiencing the encroachment of woody vegetation into grasslands. These changes in ecosystem structure and processes can result in increased sediment and nutrient fluxes due to fluvial erosion. As these changes are often accompanied by a shift from C(4) to C(3) vegetation with characteristic δ(13) C values, stable isotope analysis provides a promising mechanism for tracing these fluxes.Input vegetation, surface sediment and fluvially eroded sediment samples were collected across two contrasting C(4) -C(3) dryland vegetation transitions in New Mexico, USA. Isotope ratio mass spectrometric analyses were performed using a Carlo Erba NA2000 analyser interfaced to a SerCon 20-22 isotope ratio mass spectrometer to determine bulk δ(13) C values.Stable isotope analyses of contemporary input vegetation and surface sediments over the monitored transitions showed significant differences (p <0.05) in the bulk δ(13) C values of C(4) Bouteloua sp. (grama) grassland, C(3) Larrea tridentata (creosote) shrubland and C(3) Pinus edulis/Juniperus monosperma (piñon-juniper) woodland sites. Significantly, this distinctive δ(13) C value was maintained in the bulk δ(13) C values of fluvially eroded sediment from each of the sites, with no significant variation between surface sediment and eroded sediment values.The significant differences in bulk δ(13) C values between sites were dependent on vegetation input. Importantly, these values were robustly expressed in fluvially eroded sediments, suggesting that stable isotope analysis is suitable for tracing sediment fluxes. Due to the prevalent nature of these dryland vegetation transitions in the USA and globally, further development of stable isotope ratio mass spectrometry has provided a valuable tool for enhanced understanding of functional changes in these ecosystems.

Keyword(s): J

Note: This research was supported by the University of Exeter and Rothamsted Research at North Wyke, NSF award DEB-0217774 to the University of New Mexico for Long-term Ecological Research and a British Society for Geomorphology student travel grant. This work represents part of the BBSRC-funded programmes at Rothamsted Research on Sustainable Soil Function and Bioenergy and Climate Change. Additional thanks go to everyone from the Sevilleta LTER/USFWS who made fieldwork for this research possible and enjoyable. Finally, thanks go to the anonymous reviewers for their helpful feedback which improved the manuscript.

---

Contributing Institute(s):

1. Agrosphäre (IBG-3)

Research Program(s):

1. Terrestrische Umwelt (P24)

Appears in the scientific report 2012

---

Database coverage:
; BIOSIS Previews ; Current Contents - Physical, Chemical and Earth Sciences ; JCR ; NCBI Molecular Biology Database ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

---