Spatial variability of the vertical migration of fallout 137Cs in the soil of a pasture, and consequences for long-term predictions.

Various transport models are presently used to predict the long-term migration behaviour of fallout radiocesium on the soil. To examine to what extent the uncertainty of these predictions is influenced by the spatial variability of the migration rates, we determined the depth profiles of Chernobyl-derived 137Cs at 100 plots in a 100 m x 100 m pasture. These data were used to obtain the frequency distributions of the characteristic transport parameters of three widely used transport models (e.

Characterization of Microbial Consortia in Paddy Rice Soil by Phospholipid Analysis.

Microbial biomass and community structure in paddy rice soil during the vegetation period of rice were estimated by analysis of their phospholipid fatty acids (PLFA), hydroxy fatty acids of lipopolysaccharides (LPS-HYFA), and phospholipid ether lipids (PLEL) directly extracted from the soil. A clear change in the composition of the community structure at different sampling periods was observed, indicated by the principal component analysis of the PLFA. A dramatic decline of ester-linked PLFA was observed in the soil samples taken at the second sampling time.

Identification of single cultured micro-organisms based on their whole-community fatty acid profiles, using an extended extraction procedure.

Fatty acid profiles obtained from single cultured organisms have been used to estimate which taxonomic groups are actually represented. The lipid extraction was modified to liberate fatty acids with ester-linkages, as well as those with non-ester-linkages and classify them in different chemically relevant groups. The discriminatory power of fatty acids, in different chemically relevant fractions and subfractions varied considerably.

Phospholipid fatty acid profiles in selected members of soil microbial communities.

Fatty acids derived from phospholipids and lipopolysaccharides were investigated from 33 taxonomically different organisms (bacteria, fungi and plant cells) known a priori to inhabit soil (except E. coli). The extended extraction procedure used, liberated non-ester-linked fatty acids in addition to ester-linked fatty acids, hydroxy substituted fatty acids in three different fractions.

Emission of Climate-Relevant Trace Gases and Succession of Microbial Communities during Open-Windrow Composting.

Determination of different indicators of microbial biomass, community structure, and bioactivity by the fumigation extraction method, as well as determination of phospholipid fatty acids (PLFAs) and their subfractions and the measurement of trace gases, respectively, provides valuable information about microbial succession in composting processes. The emission rates of carbon dioxide (CO(inf2)), methane (CH(inf4)), and nitrous oxide (N(inf2)O) increased successively during compost maturation: initially in the presence of easily degradable nutrients, during high temperature, and after the temperature had cooled down, respectively. The emission rate patterns of these trace gases corresponded to the concentrations of PLFAs and their particular subfractions.