Professor Dr Nicolas Brüggemann seminar

Professor Dr Nicolas Brüggemann from the Institute for Bio- and Geosciences in Jülich, Germany, will give a seminar entitled "Use and fast detection of naturally and artificially stable-isotope-labeled compounds in ecosystem research" at the James Hutton Institute in Dundee. It will be broadcast live to the Aberdeen site.

Abstract

Stable isotope analysis can provide invaluable insight into ecosystem processes, such as plant carbon uptake and allocation, water fluxes, gas exchange, or the fate of excess nitrogen. While many physical or chemical processes lead to measurable differences in the isotopic composition of key compounds due to kinetic or equilibrium isotopic fractionation, the application of artificially enriched stable isotope tracer compounds can provide additional information about key processes, such as carbon input into the soil by plant roots, in cases where natural isotopic differences are too small, where several sources and/or sinks are involved, or where kinetics of processes are to be determined. The rapid development of infrared laser absorption spectroscopy in the recent years has enabled real-time isotope-specific analysis of a range of compounds, such as CO₂, H₂O, CH₄, or N₂O, both on the natural abundance and isotopically enriched level with a time resolution of several seconds or even better. Here, examples are shown for the application of naturally and artificially labelled isotope tracer substances in ecosystem research, such as tracing carbon fluxes from photosynthetic uptake to root and rhizosphere respiration, quantification of atmosphere–plant and atmosphere–soil CO₂ influx and efflux, or partitioning of evapotranspiration into its component fluxes evaporation and transpiration. An outlook will be given on new developments, such as analysis of CO₂ and H₂O isotopic fluxes with the eddy covariance technique using laser-based analysers.

Biography

Nicolas is head of the Plant-Soil-Atmosphere Exchange Processes Research Group at Forschungszentrum Jülich, Institute of Bio- and Geosciences – Agrosphere (IBG-3) and Professor of Terrestrial Biogeochemistry at the University of Bonn (since 2010). Prior to this he was heading the Centre of Stable Isotopes of the Institute of Meteorology and Climate Research, Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology, Garmisch-Partenkirchen. His research concentrates on nutrient cycling in terrestrial ecosystems, plant–soil–atmosphere matter fluxes and interactions, greenhouse gas exchange and stable isotope analysis in ecosystem research. He utilises a range of techniques, including isotope-ratio mass spectroscopy, isotope-specific laser infrared absorption spectroscopy and stable isotope labelling methods.

Currently, a major focus of his work is on the interactions between biotic and abiotic processes in soils, and especially on the effect of plants on soil organic and inorganic matter turnover. He is member of the editorial board of Nutrient Cycling in Agroecosystems. Dr Brüggemann spent a year at Stanford University at the Organic Chemistry Department (1995-1996), received a diploma degree in chemistry from the University of Hannover, Germany (1997) and a doctorate degree in forest and environmental sciences from the University of Freiburg, Germany (2001).