HR: 1340h
AN: B23D-1584    [Abstracts]
TI: Analysis and Modelling of Soil Carbon Dynamics and the Influence of Microbes in an Experimental Mesocosm Design
AU: * Schulze, S
EM: Stefany.Schulze@bgc-jena.mpg.de
AF: Max Planck Institute for Biogeochemistry, Hans-Knoell-Str. 10, Jena, 07745, Germany
AU: Reichstein, M
EM: Markus.Reichstein@bgc-jena.mpg.de
AF: Max Planck Institute for Biogeochemistry, Hans-Knoell-Str. 10, Jena, 07745, Germany
AU: Gleixner, G
EM: Gerd.Gleixner@bgc-jena.mpg.de
AF: Max Planck Institute for Biogeochemistry, Hans-Knoell-Str. 10, Jena, 07745, Germany
AB: Soil is by far the largest carbon pool in terrestrial ecosystems, two to five times larger than total carbon in the current atmosphere, five times more than in living biomass on land. A lot of research has been done, but largely often concentrating on soil respiration as a overall measure of activity, but still little is known about soil carbon pool dynamics, and the influence of microbes. With the proposed experiment we want to quantify the relative usage of carbon from FOM (fresh organic matter) and/or SOM (soil organic matter) for microbes. Does microbial biomass change pool usage with varying conditions? How does temperature and moisture influence these pathways and how do they interact? A natural double label (¹³C, ¹⁴C) will be applied to mark carbon pools. The old C pool in the soil is labelled with a ¹⁴C signal and to follow the new C a ¹³C signal is used as marker (vegetation change). Two diurnal temperature treatments will be combined with two water treatments (constantly at field capacity and drying-rewetting respectively) to gain information on short direct effects of temperature (diurnal cycle) and longer-term effects (treatments). During the experiment the soil physical conditions and respiration rate will be continuously monitored. The amount and δ¹³C, δ¹⁴C values from phospholipid fatty acid (PLFA), added ¹³C labelled biomass, CO₂, soil and soil solution will be used to quantify constitution of carbon from different. Experiment results will be further used for modelling pool behaviour to describe temporal and spatial C dynamics.
DE: 0402 Agricultural systems
DE: 0428 Carbon cycling (4806)
DE: 0463 Microbe/mineral interactions
DE: 0486 Soils/pedology (1865)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting