C/N transformation by soil organisms
 
Staff-members involved
J. Augustin, M. Joschko, P. Lentzsch, A. Ulrich, S. Wirth

Soil organisms contribute substantially to maintaining the global C and N cycles. A great role in this respect is played by the processes of mineralisation and humification of plant residues (products of plant matter formation) operating in soil, which lead to the release and deposition of nutrients or to the contamination with, or the decontamination of environmentally hazardous substances, such as greenhouse gases. There are close interactions between composition, structure and spatial distribution of the communities of soil organisms, on the one hand, and the kind and intensity of C/N transformations, on the other. These interactions, in turn, are influenced in a complex way by site conditions, specifically by soil and climate, by the quantity and composition of available substrates. The exploration, quantification and modelling of these relationships constitute an essential prerequisite for estimating the effect of changed land-use and climatic conditions on the C and N cycles, as well as for the development of effective and innovative land use systems.
In view of the complexity of this research subject, significant knowledge progress can only be attained by an intensified combination of study methods of soil biology and molecular genetics with isotope and gas exchange measurement techniques. This is done in conjunction with statistical procedures such as spatio-temporal series analysis, algorithms of response of soil organisms and models simulating the C/N dynamics. The work is focussed on the influence of land use changes on the degradation of dead plant matter in the context of site and region.

Patters in space and time of the functionality and diversity of communities of soil organisms -  Structure and function of microbial communities in agriculturally and    silviculturally used systems (soft-money projects: DFG project    "Forest conversion and soil microflora", DFG project "Cellulose-de-    composing soil microflora") -  Pattern in space and time of the functionally and diversity of communi-    ties of soil organisms (soft-money projects: Project Rentenbank /    Monsanto "Enhancing soil fauna by reduced tillage", LUA-Project    "Indication of the habitat function of soil by means of macro-    fauna", DAAD/BMVEL "Development of an indicator for soil biodiver-    sity")   Carbon sequestration potentials of soil landscapes under changed land use and CO2-C-sequestration by plant matter production -  Conversion dynamics of rhizodeposition (DFG-SPP 1090) -  Influence of soil animals on C sequestration    Function of soil landscapes as source and sink for greenhouse gases (N2O, CH4) -  Influence of reflooding of degraded peatlands of the Peene valley on    the dynamics of the C transformation processes and the emission of    greenhouse gases (CO2, N2O, CH4) (Mecklenburg-Western Pomera-    nia Project, cooperation with the Institute of Hydrological Ecology and    the University of Poznan) -  Greenhouse emission in alder swamp forests (DBU Common    Project  "Alnus")   Significance of plant matter production and matter transformation in functionally discrete contact zones for the matter balance of landscapes - Measurement and modelling of current N2O emissions - Influence of reflooding on N conversion dynamics in soil